IMPLANT FOR TREATMENT OF AN OCULAR CONDITION
20230190643 · 2023-06-22
Inventors
- Andres Garcia (Durham, NC, US)
- Rozemarijn Suzanne Verhoeven (Pittsboro, NC, US)
- Tomas Navratil (Carrboro, NC)
- Rhett Schiffman (Morrisville, NC, US)
Cpc classification
A61L2430/16
HUMAN NECESSITIES
A61K47/10
HUMAN NECESSITIES
A61L27/18
HUMAN NECESSITIES
A61K31/573
HUMAN NECESSITIES
A61L27/18
HUMAN NECESSITIES
A61L27/54
HUMAN NECESSITIES
International classification
A61K9/00
HUMAN NECESSITIES
A61K47/10
HUMAN NECESSITIES
A61L27/18
HUMAN NECESSITIES
A61L27/54
HUMAN NECESSITIES
Abstract
The present disclosure relates to the field of pharmaceutical compositions, ocular implants, and systems and methods for treating an ocular condition. In certain aspects, the disclosure provides ocular implant systems for treating post-operative inflammation. In certain aspects, the ocular implants taught herein are rapid release extended treatment implants.
Claims
1. An extended treatment rapid delivery system for treating post-operative ocular inflammation in an eye of a patient in need thereof, comprising: A) a biocompatible polymer matrix based ocular implant rapid delivery vehicle; and B) at least one therapeutic agent homogeneously dispersed within the polymer matrix, wherein said ocular implant rapid delivery vehicle is formulated to substantially disintegrate within 24 hours of being placed into the eye, and wherein said disintegration of the ocular implant rapid delivery vehicle results in substantially all of the at least one therapeutic agent being released into the eye within 24 hours, and wherein the at least one therapeutic agent provides a therapeutic effect to the eye of the patient for at least 2 days, and wherein said ocular implant rapid delivery vehicle is formulated to reduce post-operative corneal thickening in a patient in need thereof.
2-8. (canceled)
9. The extended treatment rapid delivery system of claim 1, wherein the biocompatible polymer matrix comprises poly(ethylene glycol).
10. The extended treatment rapid delivery system of claim 1, wherein the biocompatible polymer matrix comprises a mixture of two or more poly(ethylene glycol) polymers of different molecular weight.
11. The extended treatment rapid delivery system of claim 1, wherein the biocompatible polymer matrix comprises a mixture of two or more poly(ethylene glycol) polymers of different molecular weight, wherein one of said polymers has a molecular weight of about 3,350 and one of said polymers has a molecular weight of about 100,000.
12. The extended treatment rapid delivery system of claim 1, wherein the biocompatible polymer matrix comprises a mixture of two or more poly(ethylene glycol) polymers of different molecular weight, wherein one of said polymers has a molecular weight of about 3,350 and is present in an amount of about 10-20 weight percent of the total polymer and one of said polymers has a molecular weight of about 100,000 and is present in an amount of about 80-90 weight percent of the total polymer.
13. (canceled)
14. The extended treatment rapid delivery system of claim 1, wherein the biocompatible polymer matrix comprises a mixture of two or more poly(ethylene glycol) polymers of different molecular weight, wherein one of said polymers has a molecular weight of about 3,350 and is present in an amount of about 7-10 weight percent of the ocular implant and one of said polymers has a molecular weight of about 100,000 and is present in an amount of about 57-76 weight percent of the ocular implant, and wherein the at least one therapeutic agent is present in an amount of about 15-35 weight percent of the ocular implant.
15. The extended treatment rapid delivery system of claim 1, wherein the biocompatible polymer matrix comprises a mixture of two or more poly(ethylene glycol) polymers of different molecular weight, wherein one of said polymers has a molecular weight of about 3,350 and is present in an amount of about 4-7 weight percent of the ocular implant and one of said polymers has a molecular weight of about 100,000 and is present in an amount of about 35-54 weight percent of the ocular implant, and wherein the at least one therapeutic agent is present in an amount of about 40-60 weight percent of the ocular implant.
16. The extended treatment rapid delivery system of claim 1, wherein the biocompatible polymer matrix comprises a mixture of two or more poly(ethylene glycol) polymers of different molecular weight, wherein one of said polymers has a molecular weight of about 3,350 and is present in an amount of about 9-10 weight percent of the ocular implant and one of said polymers has a molecular weight of about 100,000 and is present in an amount of about 75-80 weight percent of the ocular implant, and wherein the at least one therapeutic agent is present in an amount of about 10-15 weight percent of the ocular implant.
17. The extended treatment rapid delivery system of claim 1, wherein the biocompatible polymer matrix comprises a mixture of two or more poly(ethylene glycol) polymers of different molecular weight, wherein one of said polymers has a molecular weight of about 3,350 and is present in an amount of about 10-11 weight percent of the ocular implant and one of said polymers has a molecular weight of about 100,000 and is present in an amount of about 82-85 weight percent of the ocular implant, and wherein the at least one therapeutic agent is present in an amount of about 5-8 weight percent of the ocular implant.
18. The extended treatment rapid delivery system of claim 1, wherein the biocompatible polymer matrix comprises a mixture of two or more poly(ethylene glycol) polymers of different molecular weight, wherein one of said polymers has a molecular weight of about 3,350 and is present in an amount of about 6-8 weight percent of the ocular implant and one of said polymers has a molecular weight of about 100,000 and is present in an amount of about 49-63 weight percent of the ocular implant, and wherein the at least one therapeutic agent is present in an amount of about 29-45 weight percent of the ocular implant.
19-23. (canceled)
24. The extended treatment rapid delivery system of claim 1, wherein the at least one therapeutic agent comprises a corticosteroid.
25. The extended treatment rapid delivery system of claim 1, wherein the at least one therapeutic agent comprises difluprednate.
26-55. (canceled)
56. A method for treating or preventing post-operative ocular inflammation in the eye of a human patient, comprising: administering the extended treatment rapid delivery system of claim 1, via intracameral injection or subconjunctival injection, to the eye of a human patient that has undergone ocular surgery or who is about to undergo ocular surgery.
57-58. (canceled)
59. A method for treating or preventing post-operative ocular inflammation in the eye of a human patient, comprising: administering the extended treatment rapid delivery system of claim 1, via intracameral injection or subconjunctival injection, to the eye of a human patient that has undergone cataract surgery or who is about to undergo cataract surgery.
60-61. (canceled)
62. A method for making the extended treatment rapid delivery system of claim 1, comprising: i) providing a mold, wherein the mold comprises a plurality of recessed areas formed therein; ii) disposing a volume of liquid material in the plurality of recessed areas, wherein said liquid material is a suspension of at least one crystalline therapeutic agent in a poly(ethylene glycol) melt; iii) forming a plurality of substantially uniform implants; and iv) harvesting the implants, wherein each of said implants substantially mimics the recessed areas.
63. An extended treatment rapid delivery system for treating post-operative ocular inflammation in an eye of a patient in need thereof, comprising: A) a biocompatible polymer matrix based ocular implant rapid delivery vehicle; and B) at least one therapeutic agent homogeneously dispersed within the polymer matrix, wherein said ocular implant rapid delivery vehicle is formulated to reduce corneal thickening, wherein the corneal thickening is associated with administration of a hydrophilic implant.
64. (canceled)
65. The extended treatment rapid delivery system of claim 63, wherein the biocompatible polymer matrix comprises a mixture of two or more poly(ethylene glycol) polymers of different molecular weight.
66. The extended treatment rapid delivery system of claim 63, wherein the biocompatible polymer matrix comprises a mixture of two or more poly(ethylene glycol) polymers of different molecular weight, wherein one of said polymers has a molecular weight of about 3,350 and one of said polymers has a molecular weight of about 100,000.
67. The extended treatment rapid delivery system of claim 63, wherein the biocompatible polymer matrix comprises a mixture of two or more poly(ethylene glycol) polymers of different molecular weight, wherein one of said polymers has a molecular weight of about 3,350 and is present in an amount of about 10-20 weight percent of the total polymer and one of said polymers has a molecular weight of about 100,000 and is present in an amount of about 80-90 weight percent of the total polymer.
68. The extended treatment rapid delivery system of claim 63, wherein the biocompatible polymer matrix comprises a mixture of two or more poly(ethylene glycol) polymers of different molecular weight, wherein one of said polymers has a molecular weight of about 3,350 and is present in an amount of about 11 weight percent of the total polymer and one of said polymers has a molecular weight of about 100,000 and is present in an amount of about 89 weight percent of the total polymer.
69-76. (canceled)
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
[0158] Provided herein are pharmaceutical compositions for treating or preventing an ocular condition. In embodiments, the pharmaceutical composition comprises: a biocompatible polymer matrix and a therapeutic agent, which is included in the polymer matrix. The therapeutic agent may be dispersed homogeneously throughout the polymer matrix.
[0159] As described herein, multiple pharmaceutical compositions have been fabricated and/or contemplated in the form of an implant, resulting in highly effective pharmaceutically active products, including ocular therapeutic treatments, including: (1) sustained release ocular implants, as well as (2) immediate/rapid delivery and extended treatment ocular implants.
[0160] In various embodiments, these pharmaceutical compositions include a therapeutic agent dispersed throughout a polymer matrix formed into an ocular implant. In some aspects, the ocular implant degrades slowly in a human eye and gradually, or in a sustained way, releases the active therapeutic agent. In other aspects, the ocular implant dissolves immediately upon being exposed to the physiological conditions of an eye, and the active therapeutic agent is available to treat the loci for an extended amount of time.
[0161] In a particular embodiment, the pharmaceutical composition of the present disclosure comprises: i) a biocompatible polymer or polymers, and ii) a therapeutic agent such as, for example, a drug effective for use in the prevention and/or treatment of an ocular condition, such as post-operative inflammation and/or pain.
[0162] Definitions
[0163] “About” means plus or minus a percent (e.g., ±10% or ±5%) of the number, parameter, or characteristic so qualified, which would be understood as appropriate by a skilled artisan to the scientific context in which the term is utilized. Furthermore, since all numbers, values, and expressions referring to quantities used herein, are subject to the various uncertainties of measurement encountered in the art, then unless otherwise indicated, all presented values may be understood as modified by the term “about.”
[0164] As used herein, the articles “a,” “an,” and “the” may include plural referents unless otherwise expressly limited to one-referent, or if it would be obvious to a skilled artisan from the context of the sentence that the article referred to a singular referent.
[0165] Where a numerical range is disclosed herein, then such a range is continuous, inclusive of both the minimum and maximum values of the range, as well as every value between such minimum and maximum values. Still further, where a range refers to integers, every integer between the minimum and maximum values of such range is included. In addition, where multiple ranges are provided to describe a feature or characteristic, such ranges can be combined. That is to say that, unless otherwise indicated, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein. For example, a stated range of from “1 to 10” should be considered to include any and all subranges between the minimum value of 1 and the maximum value of 10. Exemplary subranges of the range “1 to 10” include, but are not limited to, 1 to 6.1, 3.5 to 7.8, and 5.5 to 10.
[0166] As used herein, the term “polymer” is meant to encompass both homopolymers (polymers having only one type of repeating unit) and copolymers (a polymer having more than one type of repeating unit).
[0167] “Biodegradable polymer” means a polymer or polymers, which degrade in vivo, under physiological conditions. The release of the therapeutic agent occurs concurrent with, or subsequent to, the degradation of a biodegradable polymer over time.
[0168] The terms “biodegradable” and “bioerodible” are used interchangeably herein. A biodegradable polymer may be a homopolymer, a copolymer, or a polymer comprising more than two different polymeric units.
[0169] As used herein, the term “biocompatible” means a material, such as a polymer, that is compatible with living tissue. Biocompatible polymers may be biodegradable, bioerodible, or dissolvable.
[0170] As used herein, the term “polymer matrix” refers to a homogeneous mixture of polymers. In other words, the polymer matrix does not include a mixture of polymers wherein one portion of the polymer matrix is different from the other portion by ingredient, density, and etc. For example, the polymer matrix does not include a composition containing a core and one or more outer layers, nor a composition containing a drug reservoir and one or more portions surrounding the drug reservoir. The mixture of polymers may be of the same type, e.g. two different PEG polymers, or of different types, e.g. PEG polymers combined with PCL polymers.
[0171] “Ocular condition” means a disease, ailment, or condition, which affects or involves the ocular region.
[0172] The term “hot-melt extrusion” or “hot-melt extruded” is used herein to describe a process, whereby a blended composition is heated and/or compressed to a molten (or softened) state and subsequently forced through an orifice, where the extruded product (extrudate) is formed into its final shape, in which it solidifies upon cooling.
[0173] The term “non-extruded implant” or “non-hot melt extruded implant” refers to an implant that was not manufactured in a process that utilizes an extrusion step.
[0174] As used herein, “drug release” refers to the release of the at least one therapeutic agent, or drug, from an implant. The drug release may be sustained release, controlled release, or rapid release.
[0175] “Sustained release” or “controlled release” refers to the release of at least one therapeutic agent, or drug, from an implant at a predetermined rate. Sustained release implies that the therapeutic agent is not released from the implant sporadically, in an unpredictable fashion. The term “sustained release” may include a “burst phenomenon” associated with deployment. In some example embodiments, an initial burst of at least one therapeutic agent may be desirable, followed by a more gradual release thereafter. The release rate may be steady state (commonly referred to as “timed release” or zero order kinetics), that is the at least one therapeutic agent is released in even amounts over a predetermined time (with or without an initial burst phase), or may be a gradient release.
[0176] In some embodiments, the ocular implant polymer matrix fully disintegrates, dissolves, dissociates, dissolutes, and/or otherwise completely diminishes, upon placement into the eye under normal physiological conditions. In these embodiments, the ocular implant is often termed a “rapid delivery vehicle” or “rapid release vehicle.” The ocular implant fully, or nearly completely, dissolves upon placement into the eye and consequently releases the entirety of the therapeutic agent payload dispersed within said ocular implant polymer matrix. Consequently, in these embodiments, it is the pharmacokinetics associated with the therapeutic agent contained within the ocular implant that allows for the achievement of an extended treatment concentration of drug, in the surrounding tissues of the eye that prevents and/or treats a condition of the eye, such as for example: post-operative inflammation, allergy, pain, combinations thereof, and the like. For example, factors such as the therapeutic agent content, the water solubility of the therapeutic agent, the route of administration, and the physicochemical properties of the therapeutic agent all factor to control the “extended treatment” availability of the therapeutic agent to the loci of the eye. In some aspects, the physiochemical attributes of difluprednate, in combination with the rapid delivery ocular implant (e.g. a PEG based implant that immediately dissolves upon placement into an aqueous environment) and its subsequent subconjunctival or intracameral placement, leads to an extended treatment bioavailability of difluprednate for at least 2 days, or 7 days, or 14 days, or 20 days, or at least about 28 days in an eye.
[0177] “Therapeutically effective amount” means a level or amount of a therapeutic agent needed to treat an ocular condition; or the level or amount of a therapeutic agent that produces a therapeutic response or desired effect in the subject to which the therapeutic agent was administered. Thus, a therapeutically effective amount of a therapeutic agent, such as a difluprednate, is an amount that is effective in reducing at least one symptom of an ocular condition. Achieving a therapeutically effective amount may be achieved through sustained release of a therapeutic agent from an implant or through extended treatment when a therapeutic agent is rapidly released from an implant and the therapeutic agent provides extended treatment over time.
[0178] As used herein, the term “baseline” refers to a proper reference measurement established prior to surgery. The baseline measurement can be obtained by any suitable method. In some embodiments, “baseline” refers to the thickness of the cornea prior to surgery. In other embodiments, “baseline” refers to the thickness of the cornea prior to administration of an ocular implant. In still other embodiments, “baseline” refers intraocular pressure measured prior to surgery. In yet other embodiments, “baseline” refers to the intraocular pressure of a healthy eye.
[0179] As used herein, PEG is used to represent poly(ethylene glycol) of all molecular weights including polyethylene oxides.
[0180] Ocular Anatomy
[0181] In particular embodiments, the implants described herein are subconjunctival implants manufactured for placement into the subconjunctival region of the human eye.
[0182] In particular embodiments, the implants described herein are intracameral implants manufactured for placement into the intracameral region of the human eye.
[0183] In certain embodiments, the steady and sustained release of therapeutic agent from the implant achieves a concentration of drug in the surrounding tissues of the eye that prevents and/or treats a condition of the eye, such as for example post-operative inflammation, allergy, pain, combinations thereof, and the like.
[0184] Therapeutic agents for the treatment of ocular inflammation are typically administered to the eye in solution-based formulations. For example, DUREZOL® is an emulsion which is applied topically to the eye as eye drops, and U.S. Patent Application Publication 2016/0120879 describes injectable suspensions which are administered into the anterior chamber of the eye. However, such solution-based formulations suffer from imprecise localization of the active at the site of inflammation, which reduces efficacy. Additionally, injectable suspensions can result in adverse events, such as blurred vision, due to localization of the suspension near the cornea. Further, the therapeutic agents contained within the suspension can polymerize after administration, which also reduces efficacy.
[0185] In contrast to solution-based formulations, the implants disclosed herein are formulated to remain localized at the site of administration, which improves efficacy and reduces the incidence of adverse events associated with translocation of injectable suspensions. The implants disclosed herein are formulated to prevent aggregation of the therapeutic agents. Further, the implants exhibit improved dose uniformity compared to solution-based formulations.
[0186] Biocompatible Polymers
[0187] In certain embodiments, the implants described herein are engineered to provide maximal approximation of the implant to the human eye. In certain embodiments, the implants are made of polymeric materials.
[0188] In embodiments, the polymer materials used to form the implants described herein are biodegradable. In embodiments, the polymer materials may be any combination of polylactic acid, glycolic acid, polycaprolactone (PCL), and co-polymers thereof, which provides sustained-release of the therapeutic agent into the eye over time.
[0189] Suitable polymeric materials or compositions for use in the implants include those materials which are compatible, which is biocompatible, with the eye so as to cause no substantial interference with the functioning or physiology of the eye. Such polymeric materials may be biocompatible, biodegradable, or bioerodible In particular embodiments, examples of useful polymeric materials include, without limitation, such materials derived from and/or including organic esters and organic ethers, which when degraded result in physiologically acceptable degradation products. Also, polymeric materials derived from and/or including, anhydrides, amides, orthoesters and the like, by themselves or in combination with other monomers, may also find use in the present disclosure. The polymeric materials may be addition or condensation polymers. The polymeric materials may be cross-linked or non-cross-linked. For some embodiments, besides carbon and hydrogen, the polymers will include at least one of oxygen and nitrogen. The oxygen may be present as oxy, e.g. hydroxy or ether, carbonyl, e.g. non-oxo-carbonyl, such as carboxylic acid ester, and the like. The nitrogen may be present as amide, cyano and amino.
[0190] In embodiments, the implant polymer matrix is selected from: (1) PEG with no other polymers mixed in (disclosed in further detail herein) to form a rapid release delivery vehicle, meaning, less than about, 12 hours, 8 hours, 4 hours, 2 hours, or 1 hour for the implant to dissolve and release its active cargo; (2) PEG/PLGA mixed polymer matrix particles (disclosed in further detail herein) that give a longer release and degradation profile for the implants, which extend for up to 1 day, 2 days, 5 days, 10 days, and 14 days; and (3) PEG/PCL mixed polymer matrix particles (disclosed in further detail herein), which extend release for more than 14 days, 20 days, or 28 days.
[0191] In one embodiment, polymers of hydroxyaliphatic carboxylic acids, either homopolymers or copolymers, and polysaccharides are useful in the implants. Polyesters can include polymers of D-lactic acid, L-lactic acid, racemic lactic acid, glycolic acid, polycaprolactone, co-polymers thereof, and combinations thereof.
[0192] Some characteristics of the polymers or polymeric materials for use in embodiments of the present disclosure may include biocompatibility, compatibility with the selected therapeutic agent, ease of use of the polymer in making the therapeutic agent delivery systems described herein, a desired half-life in the physiological environment, and hydrophilicity.
[0193] In one embodiment, the biocompatible polymer matrix used to manufacture the implant is a polyether, for example a polyethylene glycol (PEG). PEGs are prepared by polymerization of ethylene oxide and are available in a wide range of molecular weights. PEG has found medical use as an excipient in pharmaceutical products, in lubricating eye drops, film coatings, and ointment bases. PEG may be synthesized at a variety of molecular weights. Used herein are PEGs with molecular weights that include 500-100,000,000 Da, 2,000 Da, 3,000 Da, 3,300 Da, 3,350 Da, 100,000 Da, 3,000 Da, 35,000 Da, 100,000 Da, and 1,000,000 Da. In some aspects, PEGs with molecular weights from 500 to 1,000,000 Daltons are used. PEG is represented by the general structure (1).
##STR00001##
[0194] In one embodiment utilizing PEGs, the ocular implant formulations will be comprised of micronized difluprednate, the active ingredient, and a blend of two PEGs with different average molecular weights, the inactive ingredients. The PEGs will have an average molecular weight of 100,000 daltons (Da) (PEG 100K) and 3,350 Da (PEG 3,350). These water-soluble PEGs function as both a diluent and a binder for the micronized difluprednate to form an injectable, solid implant formulation.
[0195] PEG 100K is a relatively large and hard polymer. Because of these physical characteristics, implants comprising PEG 100K as the sole polymer in a polymer matrix typically do not contain a homogenous dispersion of a therapeutic agent, and the amount of therapeutic agent between batches is not uniform. PEG 3,350 is a relatively small and soft polymer. PEG 3,350 is difficult to handle during processing, which typically results in non-uniform dosages of therapeutic agent between batches. However, the inventors discovered that the combination of PEG 100K and PEG 3,350, at the ratios disclosed herein, can in some aspects be critical to fabricating implants with dose uniformity.
[0196] In embodiments, the PEGs are long-chain polymers of ethylene oxide with a formula of OH—(CH.sub.2—CH.sub.2—O).sub.n—H, where n is the average number of oxyethylene groups present in the molecule. These polymers have been used extensively in approved products across multiple routes of administration including oral, topical, ophthalmic, rectal, vaginal, intrasynovial, intra-articular, intramuscular, and intravenous (Inactive Ingredients Database). PEGs are generally considered to have low toxicity by all routes of administration, and have been shown to be very safe in a large battery of tests using a large range of routes and molecular weights (Herold 1982, Smyth 1947, Smyth 1950, Smyth 1970, Webster 2009).
[0197] In one embodiment, the biocompatible polymer matrix used to manufacture the implant is a synthetic aliphatic polyester, for example a polycaprolactone. PCL is formed by ring opening polymerization of ε-caprolactone. Polycaprolactone degrades by hydrolysis of its ester linkages. Polycaprolactone has found use in medical devices such as sutures, tissue scaffold, or as dental splints. Polycaprolactone may be synthesized at a variety of molecular weights. Preferred molecular weights, in some aspects, include 2,000 Da, 14,000 Da, and 45,000 Da. In some aspects, PCL with a molecular weight of from 2000 to 45,000 Daltons are used. Polycaprolactone is represented by the general structure (2).
##STR00002##
[0198] In one embodiment, the biocompatible polymer matrix used to manufacture the implant is a synthetic aliphatic polyester, for example, a polymer of lactic acid and/or glycolic acid, and includes poly-(D,L-lactide) (PLA), polyglycolic acid (PGA), and/or the copolymer poly-(D,L-lactide-co-glycolide) (PLGA).
[0199] PLGA and PLA polymers are known to degrade via backbone hydrolysis (bulk erosion) and the final degradation products are lactic and glycolic acids, which are non-toxic and considered natural metabolic compounds. Lactic and glycolic acids are eliminated safely via the Krebs cycle by conversion to carbon dioxide and water.
[0200] PLGA is synthesized through random ring-opening co-polymerization of the cyclic dimers of glycolic acid and lactic acid. Successive monomeric units of glycolic or lactic acid are linked together by ester linkages. The ratio of lactide to glycolide can be varied, altering the biodegradation characteristics of the product. By altering the ratio it is possible to tailor the polymer degradation time. Importantly, drug release characteristics are affected by the rate of biodegradation, molecular weight, and degree of crystallinity in drug delivery systems. By altering and customizing the biocompatible polymer matrix, the drug delivery profile can be changed.
[0201] PCL, PLA, PGA, and PLGA are cleaved predominantly by non-enzymatic hydrolysis of its ester linkages throughout the polymer matrix, in the presence of water in the surrounding tissues. PCL, PLA, PGA, and PLGA polymers are biocompatible, because they undergo hydrolysis in the body to produce the original monomers. Lactic and glycolic acids are nontoxic and eliminated safely via the Krebs cycle by conversion to carbon dioxide and water. The biocompatibility of PCL, PLA, PGA and PLGA polymers has been further examined in both non-ocular and ocular tissues of animals and humans. The findings indicate that the polymers are well tolerated.
[0202] Examples of PLA polymers, which may be utilized in an embodiment of the disclosure, include the RESOMER® Product line available from Evonik Industries identified as, but are not limited to, R 207 S, R 202 S, R 202 H, R 203 S, R 203 H, R 205 S, R 208, R 206, and R 104. Examples of suitable PLA polymers include both acid and ester terminated polymers with inherent viscosities ranging from approximately 0.15 to approximately 2.2 dL/g when measured at 0.1% w/v in CHCl.sub.3 at 25° C. with an Ubbelhode size 0 c glass capillary viscometer.
[0203] The synthesis of various molecular weights of PLA is possible. In one embodiment, PLA, such as RESOMER® R208S, with an inherent viscosity of approximately 1.8 to approximately 2.2 dl/g, can be used. In another embodiment, PLA, such as RESOMER® R203S, with an inherent viscosity of approximately 0.25 to approximately 0.35 dl/g can be used
[0204] Resomer's R203S and R208S are poly(D,L-lactide) or PLA ester-terminated polymers with the general structure (3):
##STR00003##
[0205] Examples of PLGA polymers, which may be utilized in an embodiment of the disclosure, include the RESOMER® Product line from Evonik industries, including RG 502, RG 502 H, RG 503, RG 503 H, RG 504, RG 504 H, RG 505, RG 506, RG 653 H, RG 752 H, RG 752 S, RG 753 H, RG 753 S, RG 755, RG 755 S, RG 756, RG 756 S, RG 757 S, RG 750 S, RG 858, and RG 858 S. Such PLGA polymers include both acid and ester terminated polymers with inherent viscosities ranging from approximately 0.14 to approximately 1.7 dl/g when measured at 0.1% w/v in CHCl.sub.3 at 25° C. with an Ubbelhode size 0 c glass capillary viscometer. Example polymers used in various embodiments of the disclosure may include variation in the mole ratio of D,L-lactide to glycolide from approximately 50:50 to approximately 85:15, including, but not limited to, 50:50, 65:35, 75:25, and 85:15.
[0206] The synthesis of various molecular weights of PLGA with various D,L-lactide-glycolide ratios is possible. In one embodiment, PLGA, such as RESOMER® RG 752 S, with an inherent viscosity of approximately 0.16 to approximately 0.24 dl/g can be used as the matrix material of the present implants.
[0207] Resomer RG752S is a poly(D,L-lactide-co-glycolide) or ester-terminated PLGA copolymer (lactide:glycolide ratio of 75:25) with the general structure (4):
##STR00004##
[0208] The polymers used to form the implants of the disclosure have independent properties associated with them that when combined provide the properties needed to provide release of a therapeutically effective amount.
[0209] A few of the primary polymer characteristics that control therapeutic agent release rates are: polymer solubility, the molecular weight distribution, polymer end group, for example, acid or ester, and the ratio of polymers and/or copolymers in the polymer matrix. The present disclosure provides examples of polymer matrices that possess desirable therapeutic agent release characteristics by manipulating one or more of the aforementioned properties to develop a suitable ocular implant.
[0210] Drug Release Profile Manipulation
[0211] The rate of drug release from biocompatible implants depends on several factors. For example, the surface area of the implant, the therapeutic agent content, the water solubility of the therapeutic agent, and the speed of polymer degradation or dissolution.
[0212] The versatility of PCL, PEG, PGA, PLA, and PLGA allows for construction of delivery systems to tailor the drug release for treating a variety of front and back of the eye diseases.
[0213] When the versatility of PCL, PEG, PGA, PLA, and PLGA polymers are combined with the manufacturing techniques of the present disclosure, for example PRINT® (Envisia Therapeutics Inc.) particle fabrication technology, then a host of custom tailored and highly consistent and predictable drug release profiles can be created, which were not possible based upon the technology of the prior art, such as for example extrusion.
[0214] That is, with the present mold based particle fabrication technology, implants can be manufactured that exhibit a drug release profile that has highly reproducible characteristics implant to implant. The drug release profiles exhibited by various implants of the present disclosure are consistent implant to implant and demonstrate variation that is not statistically significant. Consequently, the drug release profiles demonstrated by embodiments of the implants exhibit coefficients of variation that are within a confidence interval and not biologically relevant. The ability to produce implants that demonstrate such a high degree of consistent drug release is advancement over the state of the art.
[0215] Drug Release Kinetics
[0216] Drug release is influenced by many factors including: polymer composition, therapeutic agent content, implant morphology, porosity, tortuosity, surface area, method of manufacture, and deviation from sink conditions, just to name a few. The present mold based manufacturing techniques—utilized in embodiments of the disclosure—are able to manipulate implant morphology, porosity, tortuosity, and surface area in ways that the prior art methods were incapable of doing. For instance, the highly consistent drug release profiles, highly consistent implant morphologies, and highly consistent homogeneous drug dispersions achievable by the present methods, were not available to prior art practitioners relegated to utilizing a heat extrusion based method of manufacture.
[0217] In general, therapeutic agent release occurs in 3 phases: (a) an initial burst release of therapeutic agent from the surface, (b) followed by a period of diffusional release, which is governed by the inherent dissolution of therapeutic agent (diffusion through internal pores into the surrounding media) and lastly, (c) therapeutic agent release associated with biodegradation of the polymer matrix. The rapid achievement of high therapeutic agent concentrations, followed by a longer period of continuous lower-dose release, makes such delivery systems ideally suited for acute-onset diseases that require a loading dose of therapeutic agent followed by tapering doses.
[0218] More recent advancements in drug delivery systems have allowed for biphasic release characteristics with an initial high (burst) rate of therapeutic agent release followed by sustained zero-order (linear) kinetic release (i.e., therapeutic agent release rate from the polymer matrix is steady and independent of the therapeutic agent concentration in the surrounding milieu) over longer periods. In addition, when desired for treating chronic diseases such as elevated IOP, these therapeutic agent delivery systems can be designed to have steady state release following zero order kinetics from the onset.
[0219] In aspects, the mono-polymeric PEG implants of the present disclosure, however, do not follow the above bi and tri phase release profiles. The PEG implants of the present disclosure, in embodiments, are rapid release, where the PEG monomers disassociate with each other when exposed to biologic conditions and the therapeutic agent captured therein is released into the surrounding tissues.
[0220] Therapeutic Agents
[0221] Suitable therapeutic agents for use in various embodiments of the disclosure may be found in the Orange Book published by the Food and Drug Administration, which lists therapeutic agents approved for treating post-operative inflammation.
[0222] In some embodiments, the therapeutic agents that can be used according to the disclosure include: steroids, corticosteroids, NSAIDs, allergy medications, antihistamines, antibiotics, pharmaceutically acceptable salts thereof, biologic molecules, and combinations thereof.
[0223] Suitable examples of the aforementioned steroids include, but are not limited to, 21-acetoxypregnenolone, alclometasone, algestone, amcinonide, beclomethasone, betamethasone, budesonide, chloroprednisone, clobetasol, clobetasone, clocortolone, cloprednol, corticosterone, cortisone, cortivazol, deflazacort, desonide, desoximetasone, dexamethasone, diflorasone, diflucortolone, difluprednate, enoxolone, fluazacort flucloronide, flumethasone, flunisolide, fluocinolone acetonide, fluocinonide, fluocortin butyl, fluocortolone, fluorometholone, fluperolone acetate, fluprednidene acetate, fluprednisolone, flurandrenolide, fluticasone propionate, formocortal, halcinonide, halobetasol propionate, halometasone, halopredone acetate, hydrocortamate, hydrocortisone, loteprednol etabonate, mazipredone, medrysone, meprednisone, methylprednisolone, mometasone furoate, paramethasone, prednicarbate, prednisolone, prednisolone 25-diethylamino-acetate, prednisolone sodium phosphate, prednisone, prednival, prednylidene, rimexolone, tixocortol, triamcinolone, triamcinolone acetonide, triamcinolone benetonide, triamcinolone hexacetonide, fluocinolone.
[0224] Suitable examples of the aforementioned corticosteroids include, but are not limited to, cortisone, prednisolone, fluorometholone, dexamethasone, difluprednate, medrysone, loteprednol, fluazacort, hydrocortisone, prednisone, betamethasone, prednisone, prednisolone, fluocinolone acetonide, methylprednisolone, triamcinolone hexacetonide, paramethasone acetate, diflorasone, fluocinonide, rimexolone, derivatives thereof, and mixtures thereof.
[0225] Suitable examples of the aforementioned NSAIDs include, but are not limited to, aspirin, diclofenac, flurbiprofen, ibuprofen, ketorolac, naproxen, bromfenac, and suprofen.
[0226] Suitable examples of the aforementioned allergy medications and antihistamines include, but are not limited to, loratadine, hydroxyzine, diphenhydramine, chlorpheniramine, brompheniramine, cyproheptadine, terfenadine, clemastine, triprolidine, carbinoxamine, diphenylpyraline, phenindamine, azatadine, tripelennamine, dexchlorpheniramine, dexbrompheniramine, methdilazine, and trimeprazine doxylamine, pheniramine, pyrilamine, chlorcyclizine, thonzylamine, and derivatives thereof.
[0227] Suitable examples of the aforementioned antibiotics include, but are not limited to, cefazolin, cephradine, cefaclor, cephapirin, ceftizoxime, cefoperazone, cefotetan, cefutoxime, cefotaxime, cefadroxil, ceftazidime, cephalexin, cephalothin, cefamandole, cefoxitin, cefonicid, ceforanide, ceftriaxone, cefadroxil, cephradine, cefuroxime, ampicillin, amoxicillin, cyclacillin, ampicillin, penicillin G, penicillin V potassium, piperacillin, oxacillin, bacampicillin, cloxacillin, ticarcillin, azlocillin, carbenicillin, methicillin, nafcillin, erythromycin, tetracycline, doxycycline, minocycline, aztreonam, chloramphenicol, ciprofloxacin hydrochloride, clindamycin, metronidazole, gentamicin, lincomycin, tobramycin, vancomycin, polymyxin B sulfate, colistimethate, colistin, azithromycin, augmentin, sulfamethoxazole, trimethoprim, and derivatives thereof.
[0228] In one embodiment, the implants of the present disclosure utilize dexamethasone, fluticasone, bromfenac sodium, loteprednol etabonate, or difluprednate.
[0229] In a particular embodiment, the implants of the present disclosure utilize difluprednate.
[0230] Difluprednate
[0231] Difluprednate is a synthetic GR agonist, and a difluorinated derivative of prednisolone. Difluprednate may be provided in a micronized form in order to ensure consistent biopharmaceutical properties when incorporated into the final dosage form. The chemical structure of difluprednate is found below:
##STR00005##
[0232] Difluprednate undergoes deacetylation in vivo to 6α,9-difluoroprednisolone 17-butyrate (deacetyl difluprednate; DFB), an active metabolite of difluprednate.
[0233] Pharmaceutical Compositions
[0234] In embodiments, the pharmaceutical composition is comprised of the biocompatible polymer matrix and at least one therapeutic agent.
[0235] The biocompatible polymer matrix is comprised of polymers meeting the desired characteristics. For example, desired characteristics may include a specific therapeutic agent release rate or a specific duration of action. The biocompatible polymer matrix may be comprised of one polymer, two polymers, or many polymers, such as three, four, five polymers, or more polymers.
[0236] In some embodiments, the compositions may comprise polymers utilizing the same monomer, such as compositions comprising various PEG homopolymers, or compositions comprising various PCL homopolymers. However, even if the polymers of the composition utilize the same monomer, the polymers may differ in other characteristics, such as, for example, inherent viscosity or molecular weight.
[0237] In other embodiments, the compositions may comprise polymers utilizing different monomers, such as compositions comprising a PEG homopolymer and a PCL homopolymer. However, even if the polymers of the compositions utilize different monomers, the polymers may be similar in other characteristics, such as for example, inherent viscosity or molecular weight.
[0238] In one embodiment, the pharmaceutical composition comprises a biocompatible polymer matrix and at least one therapeutic agent homogeneously dispersed throughout the polymer matrix. Further, the presently discussed pharmaceutical compositions comprising a biocompatible polymer matrix and at least one therapeutic agent, may, in certain embodiments, also exclude other polymers. That is, in some embodiments, the aforementioned polymer matrix only includes one polymer and active therapeutic agent.
[0239] In embodiments, the therapeutic agent is blended with the biocompatible polymer matrix to form the pharmaceutical composition. The amount of therapeutic agent used in the pharmaceutical composition depends on several factors such as: biocompatible polymer matrix selection, therapeutic agent selection, rate of release, duration of release desired, configuration of pharmaceutical composition, and ocular pharmacokinetics, to name a few.
[0240] For example, the therapeutic agent may comprise approximately 0.1 to approximately 60.0 weight percent of the pharmaceutical composition. In some embodiments, the therapeutic agent comprises approximately 5.0 to approximately 55.0 weight percent of the pharmaceutical composition. In other embodiments, the therapeutic agent comprises approximately 20.0 to approximately 55.0 weight percent of the pharmaceutical composition.
[0241] Implants having various compositions, sizes, and shapes were fabricated and tested as set forth in the disclosure; however, it will be appreciated that these are non-limiting examples of implant designs contemplated by the present disclosure.
[0242] Fabrication of an Ocular Implant
[0243] Various methods may be used to produce the implants. Methods include, but are not limited to, solvent casting, phase separation, interfacial methods, molding, compression molding, injection molding, extrusion, co-extrusion, heat extrusion, die cutting, heat compression, and combinations thereof. In certain embodiments, the implants are molded.
[0244] In particular embodiments, the implants of the present disclosure are fabricated through the PRINT® particle fabrication technology (Envisia Therapeutics Inc., North Carolina). In particular, the implants are made by molding the materials intended to make up the implants in polymeric mold cavities.
[0245] The molds can be polymer-based molds and the mold cavities can be formed into any desired shape and dimension. Uniquely, as the implants are formed in the cavities of the mold, the implants are highly uniform with respect to shape, size, and composition. Due to the consistency among the physical and compositional makeup of each implant of the present pharmaceutical compositions, the pharmaceutical compositions of the present disclosure provide highly uniform release rates and dosing ranges. The methods and materials for fabricating the implants of the present disclosure are further described and disclosed in issued patents and pending patent applications, each of which are incorporated herein by reference in their entirety: U.S. Pat. Nos. 8,518,316; 8,444,907; 8,420,124; 8,268,446; 8,263,129; 8,158,728; 8,128,393; 7,976,759; U.S. Pat. Application Publications Nos. 2013-0249138, 2013-0241107, 2013-0228950, 2013-0202729, 2013-0011618, 2013-0256354, 2012-0189728, 2010-0003291, 2009-0165320, 2008-0131692; and pending U.S. application Ser. No. 13/852,683 filed Mar. 28, 2013 and Ser. No. 13/950,447 filed Jul. 25, 2013.
[0246] The mold cavities can be formed into various shapes and sizes. For example, the cavities may be shaped with curved edges, sharp or square edges, circular or arched perimeters, flat sides, substantially parallel sides, pointed ends, cylindrical, prism, rectangular prism, triangular prism, pyramid, square pyramid, triangular pyramid, cone, cylinder, torus, or rod. The cavities may have the same shape or may have different shapes. In certain aspects of the disclosure, the shapes of the implants are a cylinder, rectangular prism, and rod. In a particular embodiment, the implant is a rod having substantially a square, rectangular, circular, or oval cross-section taken normal to the long axis of the implant.
[0247] The mold cavities can be dimensioned from nanometer to micrometer to millimeter dimensions and larger. For certain embodiments of the disclosure, mold cavities are dimensioned in the micrometer and millimeter range. For example, cavities may have a smallest dimension of between approximately 50 nanometers and approximately 750 μm. In some aspects, the smallest mold cavity dimension may be between approximately 1 μm and approximately 500 μm. In other aspects, the smallest mold cavity dimension may be between approximately 225 μm and approximately 400 μm. For example, mold cavities may have a largest dimension of between approximately 1,000 μm and approximately 10,000 μm. In other aspects, the largest mold cavity dimension may be between approximately 2,000 μm and approximately 6,000 μm. In other aspects, the largest mold cavity dimension may be between approximately 4,000 μm and approximately 6,000 μm.
[0248] The implants can have an aspect ratio of width-to-length from 1:1 to greater than 1:30. In some embodiments, the width-to-length aspect ratio of the implant is between 1:2 to 1:25. In some embodiments, the width-to-length aspect ratio of the implant is between 1:5 to 1:20. In some embodiments, the width-to-length aspect ratio of the implant is between 1:10 to 1:20. In some embodiments, the width-to-length aspect ratio of the implant is between 1:15 to 1:20.
[0249] In one embodiment, a rod with dimensions of about 130 μm×about 180 μm×about 1,500 μm (H×W×L) is fabricated.
[0250] In one embodiment, a rod with dimensions of about 225 μm×about 225 μm×about 4,000 μm (H×W×L) is fabricated.
[0251] In another embodiment, a rod with dimensions of about 225 μm×about 225 μm×about 2,925 μm (H×W×L) is fabricated.
[0252] In another embodiment, a rod with dimensions of about 300 μm×about 300 μm×about 6,000 μm (H×W×L) is fabricated.
[0253] In another embodiment, a rod with dimensions of about 330 μm×about 330 μm×about 6,000 μm (H×W×L) is fabricated.
[0254] In a further embodiment, a rod with dimensions of about 400 μm×about 400 μm×about 6,000 μm (H×W×L) is fabricated.
[0255] Once fabricated, the implants may remain on an array for storage, or may be harvested immediately for storage and/or utilization. Implants may be fabricated using sterile processes, may be sterilized after fabrication, or may be fabricated using sterile processes and sterilized after fabrication. Thus, the present disclosure contemplates kits that include a storage array that has fabricated implants attached thereon. These storage array/implant kits provide a convenient method for mass shipping and distribution of the manufactured implants. In embodiments, fabricated implants are packaged individually.
[0256] Delivery Devices
[0257] In embodiments, a delivery device may be used to insert the implant into the eye or eyes for treatment or prevention of ocular diseases.
[0258] Suitable devices can include a needle or needle-like applicator. In some embodiments, the smallest dimension of an implant may range from approximately 50 μm to approximately 750 μm, and therefore a needle or needle-like applicator with a gauge ranging from approximately 19 to 27 may be utilized depending on the cross-sectional dimension of the implant to inner diameter of the needle as detailed elsewhere herein. The delivery device may be a syringe with an appropriately sized needle or may be a syringe-like device with a needle-like applicator.
[0259] For example, in embodiments in which an implant is sized and structure to allow for administration in a 27 gauge needle (e.g., for a rod-shaped implant having dimensions of 225 μm×about 225 μm×about 2,925 μm), the applicator needle has a gauge of 27 and a length of 13 mm. In other embodiments in which an implant is sized and structured to allow for administration in a 21 gauge needle (e.g. for a rod-shaped implant having dimensions of 300 μm×about 300 μm×about 6,000 μm), the applicator needle has a gauge of 21 and a length of 25 mm. In other embodiments in which an implant is sized and structured to allow for administration in a 25, 26, or 27 gauge needle (e.g., for a rod-shaped implant having dimensions of 130 μm×about 180 μm×about 1,500 μm), the applicator needle has a gauge of 25, 26, or 27 and length of 13 mm.
[0260] Delivery routes include punctual, intravitreal, subconjunctival, intracameral, lens, intrascleral, fornix, anterior sub-Tenon's, suprachoroidal, posterior sub-Tenon's, subretinal, anterior chamber, and posterior chamber, to name a few.
[0261] In embodiments, an implant or implants are delivered to the subconjunctival region of a patient's eye to prevent and/or treat post-operative inflammation.
[0262] In embodiments, an implant or implants are delivered to the intracameral region of a patient's eye to prevent and/or treat post-operative inflammation.
[0263] Kits
[0264] In embodiments, the implant and delivery device may be combined and presented as a kit for use.
[0265] The implant may be packaged separately from the delivery device and loaded into the delivery device just prior to use.
[0266] Also, the implant may be loaded into the delivery device prior to packaging. In this case, once the kit is opened, the delivery device is ready for use.
[0267] Components may be sterilized individually and combined into a kit, or may be sterilized after being combined into a kit.
[0268] Further, as aforementioned, a kit may include an array with implants bound thereon.
[0269] Use of Ocular Implant for Treatment
[0270] In one aspect of the disclosure, there is presented a method of preventing and/or treating post-operative inflammation. The method comprises placing a biocompatible implant in an eye, degrading or dissolving the implant, and releasing a therapeutic agent which is effective to prevent and/or treat post-operative inflammation.
[0271] In aspects of the disclosure, the eye is that of an animal. For example, a dog, cat, horse, cow (or any agricultural livestock or domesticated pet), or human.
[0272] In one aspect of the disclosure, there is presented a method of preventing and/or treating post-operative pain. The method comprises placing a biocompatible implant in an eye, degrading or dissolving the implant, and releasing a therapeutic agent which is effective to prevent and/or treat post-operative pain. The pain treated or prevented may or may not be associated with inflammation.
[0273] Corneal Thickening
[0274] Not to be bound by a particular theory, corneal thickening (also known as corneal edema) refers to inflammation which is induced in response to an ocular operation, such as surgery or administration of an ocular implant. This effect is characterized by the buildup of excess aqueous fluid in corneal tissue. Corneal thickening is well known in the art to be a factor which hinders the improvement of vision days after surgery. See Donnenfeld, et al, Am. J. of Ophthalmology, Vol 152 (4); 2011: 609-617, which is herein incorporated by reference in its entirety. Implants comprising hydrophilic polymers, such as PEGs, can also induce corneal thickening by causing cells located near the site of administration to uptake excess aqueous fluid thereby becoming inflamed. Thus, corneal thickening which occurs after ocular administration of a hydrophilic polymer can exacerbate the corneal thickening effect observed after cataract surgery and further impair vision.
[0275] Corticosteroids are known to cause thinning of the cornea after ocular administration. Thus, corticosteroids are typically administered in an emulsified formulation after cataract surgery to reduce corneal thickening. However, emulsified corticosteroid formulations are not able to reduce corneal thickening to a baseline at least a month after surgery. See Donnenfeld, et al, Am. J. of Ophthalmology, Vol 152 (4); 2011: 609-617.
[0276] In some embodiments, the inventors discovered implant formulations which overcome the limitations in the prior. Thus, in some embodiments, the implants described herein are able to reduce post-operation corneal thickening in the range of from about 1% to about 100%. That is, in some embodiments, implants can be formulated to offset post-operative corneal thickening.
[0277] In some embodiments, the implants described herein are able to reduce corneal thickening to a baseline established prior to surgery within about 30 days or less. Accordingly, in some embodiments, the implants described herein can reduce post-operative corneal thickening to a baseline within about 1 day after administration of said implant. In other embodiments, the implants described herein are able to reduce post-surgery corneal thickening below a baseline established prior to surgery by about 1% to about 10%. In further embodiments, the implants can maintain reduced post-operative corneal thickening for at least about 42 days. See
[0278] In some embodiments, implants described herein can be formulated to reduce corneal thickening observed after surgery and/or after administration of an implant. See
[0279] Course of Treatment
[0280] Over the course of treatment, the biocompatible polymer matrix degrades or dissolves releasing the therapeutic agent. Once the therapeutic agent has been completely released, the polymer matrix is expected to be degraded or dissolved. Complete polymer matrix degradation may take longer than the complete release of the therapeutic agent. Polymer matrix degradation may occur at the same rate as the release of the therapeutic agent. Polymer matrix dissolution provides for rapid release of the therapeutic agent.
[0281] Current treatments for prevention and/or treatment of post-operative inflammation require the patient to place drops in their eyes each day. The pharmaceutical composition of the disclosure is designed for release of an effective amount of therapeutic agent, eliminating the need for daily drops. The effective amount of the therapeutic agent may be provided through sustained release or rapid release. For example, the pharmaceutical composition may be designed to release an effective amount of therapeutic agent for less than one day to approximately one day, two days, three days, four days, five days, six days, seven days, eight days, nine days, ten days, eleven days, twelve days, thirteen days, fourteen days, 28 days, or longer. In aspects, the pharmaceutical composition is designed to release an effective amount of therapeutic agent for one day, two days, three days, five days, seven days, ten days, twelve days, or longer. In other aspects, the pharmaceutical composition is designed to release an effective amount of therapeutic agent for seven days, ten days, twelve days, or fourteen days.
[0282] Methods of the present disclosure for treating or preventing a condition include inserting more than 5 implants to treat or prevent the condition for more than 2 weeks. Methods of the present disclosure for treating or preventing a condition include inserting more than 10 implants to treat or prevent the condition for more than 2 weeks. Methods of the present disclosure for treating or preventing a condition include inserting more than 25 implants to treat or prevent the condition for more than 2 weeks. Methods of the present disclosure for treating or preventing a condition include inserting more than 50 implants to treat or prevent the condition for more than 2 weeks. Methods of the present disclosure for treating or preventing a condition include inserting more than 100 implants to treat or prevent the condition for more than 2 weeks. Methods of the present disclosure for treating or preventing a condition include inserting more than 500 implants to treat or prevent the condition for more than 2 weeks. Methods of the present disclosure for treating or preventing a condition include inserting more than 1,000 implants to treat or prevent the condition for more than 2 weeks. Methods of the present disclosure for treating or preventing a condition include inserting more than 10,000 implants to treat or prevent the condition for more than 2 weeks. Methods of the present disclosure for treating or preventing a condition include inserting more than 100,000 implants to treat or prevent the condition for more than 2 weeks. Methods of the present disclosure for treating or preventing a condition include inserting more than 1,000,000 implants to treat or prevent the condition for more than 2 weeks. The polymer composition and ratios of each implant in these collections of implants can be varied between implants within a single dose such that an aggregate degradation profile of the collection of implants is achieved for delivery of the therapeutic agent for greater than 2 weeks, greater than 1 month, greater than 3 months, greater than 4 months, greater than 6 months, greater than 9 months and greater than 12 months.
[0283] Delivery of implants disclosed herein may include delivery through a 27 gauge needle or smaller. In some delivery methods, the needle is 28 gauge, 29 gauge, 30 gauge, 31 gauge, 32 gauge, 33 gauge, or 34 gauge needle. In other aspects, a 21 or 22 gauge needle is used. In other aspects, a 25 or 26 gauge needle is used.
[0284] The following non-limiting examples illustrate certain aspects of the present disclosure.
EXAMPLES
Example 1: Preparation of Polymer Matrix/Therapeutic Agent Blends
[0285] A series of polymer matrix/therapeutic agent blends were prepared prior to molding implants. All blends contained difluprednate as the therapeutic agent. Table 1 details the composition of one series of blends.
TABLE-US-00001 TABLE 1 Polymer Matrix/Therapeutic Agent Blend Ratios Therapeutic Polymer Matrix Target, % Agent PLGA PEG PCL Target, % ID DLG1A 502H PEG3300 14K Difluprednate 642-64-1 40.0 10.0 50.0 642-64-2 60.2 9.8 30.0 642-64-3 70.0 30.0 642-64-4 50.0 50.0
Example 2: Fabrication of Molds
[0286] A series of molds of various dimensions were obtained for the PRINT® particle replication technology from Envisia Therapeutics Inc., North Carolina.
[0287] Molds obtained included molds with cavity sizes and shapes as follows: a) a rod shape with dimensions of about 225 μm×about 225 μm×about 4,000 μm, b) a rod shape with dimensions of about 300 μm×about 300 μm×about 6,000 μm, and c) a rod shape with dimensions of about 400 μm×about 400 μm×about 6,000 μm.
Example 3: Implant Fabrication
[0288] A series of implants were fabricated utilizing the polymer matrix/therapeutic agent blends of Example 1 and the molds of Example 2. Under aseptic conditions, a portion of polymer matrix/therapeutic agent blend was spread over a PET sheet and was heated on a hot plate for approximately 30 to 90 seconds until fluid. Once heated, the blend was covered with the mold of Example 2 which had the desired dimensions. Light pressure was applied using a hand roller to spread the blend over the mold area. The mold/blend laminate was then passed through a commercially available thermal laminator using the parameters in Table 2 below. The blend flowed into the mold cavities and assumed the shape of the mold cavities. The blend was allowed to cool to room temperature creating individual implants in the mold cavities. The mold was then removed leaving a two-dimensional array of implants on the PET film. Individual implants were removed from the PET film utilizing forceps.
TABLE-US-00002 TABLE 2 Implant Fabrication Conditions Process Parameter Hot Plate 80-180 Temperature, ° C. Hot Plate Time, 30-180 seconds
[0289] Table 3 details the implants that were produced with the blends of Example 1 and the molds of Example 2 using the fabrication process of Example 3. The same ID used for the blend was also used for the resulting implant.
TABLE-US-00003 TABLE 3 Implant Configurations ID Implant Dimensions 642-64-1 225 μm × 225 μm × 4,000 μm 642-64-2 225 μm × 225 μm × 4,000 μm 642-64-3 225 μm × 225 μm × 4,000 μm 642-64-4 225 μm × 225 μm × 4,000 μm
Example 4: Analysis of Difluprednate Content
[0290] Individual implants were placed into 2 mL HPLC vials and acetonitrile was added. The solution was diluted with an equal volume of water. The difluprednate concentration was determined using HPLC as described in Example 5 below. The mass of individual implants was also determined. Table 4 details the test results for the implants fabricated in Example 3.
TABLE-US-00004 TABLE 4 Difluprednate Content for Implants Diflu- Difluprednate, μg Overall Implant, μg prednate ID AVE STDEV % RSD AVE STDEV % RSD % 642- 129.2 5.8 4.5 252.2 14.1 5.6 51.2 64-1 642- 85.5 6.9 8.0 279.8 16.4 5.8 30.6 64-2 642- 60.3 1.5 2.5 211.2 6.7 3.2 28.6 64-3 642- 144.2 28.0 19.4 266.4 43.5 16.3 54.1 64-4
Example 5: HPLC Method for Determination of Difluprednate
[0291] Mobile phase A was prepared by combining approximately 900 mL water, approximately 100 mL acetonitrile, and approximately 1 mL trifluoroacetic acid. Mobile phase B was prepared by combining approximately 900 mL acetonitrile, approximately 100 mL water, and approximately 1 mL trifluoroacetic acid. A series of standards were prepared by diluting a known difluprednate standard.
[0292] For analysis conditions, the column was a Phenomenex Luna Phenyl-hexyl, 3 μm, 100×4.6 mm, flow rate was 1.0 mL per minute, wavelength was 244 nm, temperature was 55° C., injection volume was 5 μL, and the run time was 14 minutes. The gradient is detailed in Table 5.
TABLE-US-00005 TABLE 5 HPLC Gradient for Difluprednate Analysis Time, minutes Mobile Phase A, % Mobile Phase B, % 0 70 30 1 70 30 9 30 70 9.1 70 30 14 70 30
[0293] To determine therapeutic agent content in an implant, the measured μg/mL determined from the response associated with the standard curve was multiplied by the volume used to dissolve the implant.
Example 6: In Vitro Difluprednate Release Studies
[0294] In vitro release of difluprednate was determined for the implants of Example 3. In this study, single implants were placed into HPLC vials and were incubated in a volume of 1× PBS (phosphate buffered saline) containing 1% sodium dodecyl sulfate media at 37° C. At each time point of interest, the media was removed for analysis. The media was then replaced with fresh media. The media that was removed was analyzed for difluprednate released via the HPLC method of Example 5.
[0295]
Example 7: Preparation of Polymer Matrix/Therapeutic Agent Blends
[0296] A series of polymer matrix/therapeutic agent blends were prepared prior to molding implants. All blends contained difluprednate as the therapeutic agent. Table 6 details the composition of one series of blends.
TABLE-US-00006 TABLE 6 Polymer Matrix/Therapeutic Agent Blend Ratios Therapeutic Polymer Matrix Target, % Agent PEG PCL Target, % ID PEG3300 2K 14K Difluprednate 642-69-1 50.0 50.0 642-69-2 25.0 25.0 50.0 642-69-3 50.0 50.0 642-69-4 10.0 40.0 50.0 642-69-5 25.0 25.0 50.0
[0297] Table 7 details the implants that were produced with the blends of Example 7 and the molds of Example 2 using the fabrication process of Example 3. The same ID used for the blend was also used for the resulting implant.
TABLE-US-00007 TABLE 7 Implant Configurations ID Implant Dimensions 642-69-1 225 μm × 225 μm × 4,000 μm 642-69-2 225 μm × 225 μm × 4,000 μm 642-69-3 225 μm × 225 μm × 4,000 μm 642-69-4 225 μm × 225 μm × 4,000 μm 642-69-5 400 μm × 400 μm × 6,000 μm
[0298] Implants were analyzed for difluprednate content according to Example 4 and Example 5. Results for the implants of Example 7 are shown in Table 8.
TABLE-US-00008 TABLE 8 Difluprednate Content for Implants Diflu- Difluprednate, μg Overall Implant, μg prednate ID AVE STDEV % RSD AVE STDEV % RSD % 642- 99.2 3.0 3.0 206.0 4.5 2.2 48.1 69-1 642- 105.0 4.6 4.4 206.5 6.7 3.3 50.1 69-2 642- 115.1 6.5 5.7 227.0 7.6 3.3 51.6 69-3 642- 102.9 2.7 2.6 220.0 8.3 3.8 46.7 69-4 642- 630.5 56.3 8.9 1,197.8 95.3 8.0 51.7 69-5
Example 8: In Vitro Difluprednate Release Studies
[0299] In vitro release of difluprednate was determined for the implants of Example 7. Implants were testing according to the method of Example 6.
[0300]
[0301]
[0302] Further details of the study are shown in
[0303]
[0304] The data demonstrates that for the blends under investigation, for example 642-69-4 and 642-69-5, a smaller implant containing about the same percentage therapeutic agent but an overall lower therapeutic agent content releases the therapeutic agent for a shorter time period when compared to a larger implant. Also, the data demonstrates that use of a higher molecular weight PCL slows the release of therapeutic agent, allowing the implant to release therapeutic agent for a longer time span. When combining use of a higher and lower molecular weight PCL into the same implant configuration, the release rate of therapeutic agent is intermediate to that of each respective PCL. To increase the release rate of higher molecular weight PCL samples, PEG can also be utilized. The data demonstrates that the release rate for the therapeutic agent can be adjusted.
[0305] Further details of the study are shown n
[0306]
Example 9: Implants Utilized for In Vivo Studies
[0307] A twelve day in vivo study utilizing New Zealand White Rabbits was conducted to determine the ocular tolerability and also determine residual difluprednate in the implant at the study termination. Table 9 details the IDs of the implants, number of implants utilized for dosing, and number of eyes dosed for the studies. Tables in the previous examples provide information as to composition and dimension for the implants. Topical administration of DUREZOL® (difluprednate ophthalmic emulsion) (Alcon Laboratories, Inc.) was used as a positive control. The dosing paradigm for the positive control was one drop per eye, four times daily for the duration of the study. For a negative control the surgery was conducted, but no implant was used. Implants were placed either subconjunctivally or intracamerally. For subconjunctival placement, the implants were either directly injected into the subconjunctival tissue or a pocket was created in the subconjunctival region through a 1-2 mm incision in the conjunctiva at the place of interest. An appropriately sized needle was used to deliver the implant directly into the tissue or into the pocket. The pocket was able to contain up to three implants. For eyes containing greater than three implants, the appropriate number of pockets were created (i.e. two pockets to hold two implants each for a total of four implants delivered). For intracameral placement, implants were delivered through the limbus to the intracameral location using an appropriately sized needle as described elsewhere herein.
[0308] The Hackett-McDonald Scoring System was used to determine the Total Ocular Exam Score. A “perfect score” is equal to 0; however, a composite score that does not equal zero does not indicate a clinically unacceptable pharmaceutical composition. Residual difluprednate was determined in the retrieved implants using the method described in Example 4 and Example 5.
[0309]
[0310] Table 10 and
TABLE-US-00009 TABLE 9 In Vivo Implants Therapeutic Therapeutic Agent Agent Total Implants Eyes Content/ Content/ Dosed/Eye Dosed Implant Dose Delivery ID # # μg μg Route 642-69-2 4 4 105 420 Subcon- junctival 642-69-2 2 4 105 210 Intra- cameral 642-69-5 3 4 636 1908 Subcon- junctival Positive Not 4 60 60 Topical Control Appli- drops cable Negative Not 4 0 0 No Control Appli- implant cable
TABLE-US-00010 TABLE 10 Delivered and Retrieved Difluprednate for In Vivo Study Therapeutic Agent Therapeutic Therapeutic Therapeutic Total Agent Agent Agent Content/Dose Recovered Recovered Delivered ID Animal μg μg % % 642-69-2 34L 385 130.4 33.9 66.1 34R 420 170.4 40.6 59.4 35L 420 106.4 25.3 74.7 35R 420 230.5 54.9 45.1 Average 38.7 61.3 STDEV 12.5 12.5 642-69-2 36L 210 151.2 72.0 28.0 36R 210 144 68.6 31.4 37L 210 152.6 72.7 27.3 37R 210 141.3 67.3 32.7 Average 70.1 29.9 STDEV 2.6 2.6 642-69-5 38L 1892 1402.4 74.1 25.9 38R 1892 1390.8 73.5 26.5 39L 1892 1365.3 72.2 27.8 39R 1892 1313.9 69.4 30.6 Average 72.3 27.7 STDEV 2.1 2.1
Example 10: Polymer Matrix/Therapeutic Agent Blend Ratios
[0311] A series of polymer matrix/therapeutic agent blends were prepared prior to molding implants. All blends contained difluprednate as the therapeutic agent. Table 11 details the composition of one series of blends.
TABLE-US-00011 TABLE 11 Polymer Matrix/Therapeutic Agent Blend Ratios Therapeutic Polymer Matrix Target, % Agent PEG PCL Target, % ID PEG35K PEG100K 2K 14K 45K Glycerol Difluprednate 0053-1-1 34.3 14.7 8.8 8.8 3.5 30.0 0053-1-2 14.7 6.3 22.8 22.8 3.5 30.0 0053-1-3 22.1 9.5 17.5 17.5 3.5 30.0 0053-1-4 22.1 9.5 17.5 17.5 3.5 30.0 0053-1-5 14.7 6.3 22.8 22.8 3.5 30.0 0053-1-6 52.5 14.0 3.5 30.0 0053-4-1 34.3 14.7 8.8 8.8 3.5 30.0 0053-4-2 14.7 6.3 22.8 22.8 3.5 30.0 0053-4-3 22.1 9.5 17.5 17.5 3.5 30.0 0053-4-4 52.5 14.0 3.5 30.0 0053-4-5 24.5 10.5 31.5 3.5 30.0 0053-4-6 14.7 6.3 45.5 3.5 30.0 0053-4-7 66.5 3.5 30.0 0053-4-8 10.5 4.5 32.5 2.5 50.0 0053-4-9 5.3 2.3 40.0 3.5 50.0 0053-4-10 66.5 3.5 30.0 0053-4-11 14.7 6.3 45.5 3.5 30.0 0053-4-12 24.5 10.5 31.5 3.5 30.0 0053-4-13 27.0 11.6 14.0 14.0 3.5 30.0
Example 11: Implant Fabrication
[0312] Table 12 details the implants that were produced with the blends of Example 10 and the molds of Example 2 using the fabrication process of Example 3. The same ID used for the blend was also used for the resulting implant.
TABLE-US-00012 TABLE 12 Implant Configurations ID Implant Dimensions 0053-1-1 225 μm × 225 μm × 4,000 μm 0053-1-2 225 μm × 225 μm × 4,000 μm 0053-1-3 225 μm × 225 μm × 4,000 μm 0053-1-4 225 μm × 225 μm × 4,000 μm 0053-1-5 225 μm × 225 μm × 4,000 μm 0053-1-6 225 μm × 225 μm × 4,000 μm 0053-4-1 400 μm × 400 μm × 6,000 μm 0053-4-2 400 μm × 400 μm × 6,000 μm 0053-4-3 400 μm × 400 μm × 6,000 μm 0053-4-4 400 μm × 400 μm × 6,000 μm 0053-4-5 400 μm × 400 μm × 6,000 μm 0053-4-6 400 μm × 400 μm × 6,000 μm 0053-4-7 400 μm × 400 μm × 6,000 μm 0053-4-8 400 μm × 400 μm × 6,000 μm 0053-4-9 400 μm × 400 μm × 6,000 μm 0053-4-10 225 μm × 225 μm × 4,000 μm 0053-4-11 225 μm × 225 μm × 4,000 μm 0053-4-12 225 μm × 225 μm × 4,000 μm 0053-4-13 400 μm × 400 μm × 6,000 μm
Example 12: Analysis of Difluprednate Content
[0313] Implants were analyzed for difluprednate content according to Example 4 and Example 5. The mass of individual implants was also determined. Table 13 details the test results for the implants fabricated in Example 11.
TABLE-US-00013 TABLE 13 Difluprednate Content for Implants Difluprednate, μg Overall Implant, μg Difluprednate ID AVE STDEV % RSD AVE STDEV % RSD % 0053-1-1 73.9 4.1 5.5 222.1 22.5 10.1 33.3 0053-1-2 58.2 2.2 3.8 195.4 3.6 1.8 29.8 0053-1-3 59.4 1.8 3.0 209.9 5.1 2.4 28.3 0053-1-4 56.0 1.7 3.1 199.5 3.7 1.8 28.1 0053-1-5 57.5 1.8 3.1 192.0 3.5 1.8 30.1 0053-1-6 71.3 4.8 6.7 236.1 9.5 4.0 30.2 0053-4-1 296.1 13.6 4.6 1,255.2 93.2 7.4 24.3 0053-4-2 298.4 32.2 10.8 1,139.3 129.3 11.3 26.1 0053-4-3 275.1 48.3 17.6 1,057.6 127.9 12.1 26.5 0053-4-4 321.7 33.4 10.4 1,326.1 161.1 12.1 26.7 0053-4-5 325.2 33.7 10.4 1,172.0 119.0 10.2 27.8 0053-4-6 305.0 21.1 6.9 1,114.8 102.3 9.2 26.9 0053-4-7 264.0 18.7 7.1 1,002.3 95.0 9.5 26.0 0053-4-8 495.9 71.9 14.5 1,143.9 140.8 12.3 43.8 0053-4-9 474.1 45.9 9.7 1,100.5 113.4 10.3 45.0 0053-4-10 45.3 2.6 5.7 191.2 7.5 3.9 23.7 0053-4-11 54.2 2.6 4.8 202.5 8.0 3.9 26.8 0053-4-12 58.0 1.8 3.0 224.1 3.8 1.7 25.9 0053-4-13 292.7 20.7 7.1 1096.2 116.1 10.6 26.8
Example 13: In Vitro Difluprednate Release Studies
[0314] The in vitro release of difluprednate was determined for the implants of Example 11 according to the method of Example 6. Test results are shown in
[0315] All implants in
[0316] All samples in
Example 14: Implants Utilized for In Vivo Studies
[0317] A thirteen day in vivo study utilizing New Zealand White Rabbits was conducted to determine the ocular tolerability and effect on induced ocular inflammation over the course of the study for a select group of samples in Example 11. Table 14 details the IDs of the implants, number of implants utilized for dosing, and number of eyes dosed for the studies. Tables in the previous examples provide information as to composition and dimension for the implants. Topical administration of DUREZOL® (difluprednate ophthalmic emulsion) (Alcon Laboratories, Inc.) was used as a positive control. The dosing paradigm was one drop per eye, four times daily for the duration of the study. For a negative control the surgery was conducted and a placebo implant (no difluprednate) was inserted.
[0318] Implants were placed subconjunctivally as described in Example 9. Two models were evaluated: paracentesis and corneal incision. In the paracentesis model, approximately 100 μL aqueous humor was withdrawn from samples on days 2 and 6. In the corneal incision model, 100 μL, aqueous humor was withdrawn from animals on day 2. Additionally, corneal incision model groups had a 2.7 mm incision in the superior cornea sutured with 8-0 or 9-0 Vicryl on day 2.
[0319] The Total Ocular Exam Score was also scored as described in Example 9. All corneal incision groups had any scoring related to inflammation surrounding sutures omitted from the Total Ocular Exam Score.
TABLE-US-00014 TABLE 14 In Vivo Implants Therapeutic Agent Implants Eyes Therapeutic Agent Total Dosed/Eye Dosed Content/Implant Content/Dose ID # # μg μg Method of Delivery Placebo 3 0 0 Subconjunctival Injection Implant Positive 0 50 50 Topical Drops Control 53-1-3 2 59.5 118.9 Subconjunctival Injection 53-1-3 4 59.5 237.8 Subconjunctival Injection 53-4-4 2 343 686 Subconjunctival Injection 53-4-13 3 349 1046 Subconjunctival Injection 53-4-8 1 492 492 Subconjunctival Injection 53-4-9 ~1.9 485 922 Subconjunctival Injection 53-4-9 ~3.6 496 1786 Subconjunctival Injection 53-4-6 2 or 3 393 786 Subconjunctival Injection Placebo 3 0 0 Subconjunctival Injection Implant Positive 0 50 50 Topical Drops Control 53-4-13 2.75 325 894 Subconjunctival Injection 53-4-8 1 569 569 Subconjunctival Injection
Example 15: Polymer Matrix/Therapeutic Agent Blend Ratios
[0320] A series of polymer matrix/therapeutic agent blends were prepared prior to molding implants. All blends contained difluprednate as the therapeutic agent. Table 15 details the composition of one series of blends.
TABLE-US-00015 TABLE 15 Polymer Matrix/Therapeutic Agent Blend Ratios Polymer Matrix Therapeutic Target, % Agent PEG Target, % ID PEG35K PEG100K PEG1MM Glycerol Difluprednate 00053.23-1 45.0 5.0 50.0 00053-23.2 50.0 50.0 00053-23-3 50.0 50.0 00053-23-4 49.0 21.0 30.0 00053-23-5 35.0 15.0 50.0 00053-23-6 35.0 15.0 50.0 00053-28-1 48.7 20.9 30.4 00053-28-2 34.9 15.0 50.1 00053-28-3 50 50.0
Example 16: Implant Fabrication
[0321] Table 16 details the implants that were produced with the blends of Example 15, the molds of Example 2, and using the fabrication process of Example 3. The same ID used for the blend was also used for the resulting implant.
TABLE-US-00016 TABLE 16 Implant Configurations ID Implant Dimensions 00053.23-1 225 μm × 225 μm × 4,000 μm 00053-23.2 225 μm × 225 μm × 4,000 μm 00053-23-3 225 μm × 225 μm × 4,000 μm 00053-23-4 225 μm × 225 μm × 4,000 μm 00053-23-5 225 μm × 225 μm × 4,000 μm 00053-23-6 225 μm × 225 μm × 4,000 μm 00053-28-1 300 μm × 300 μm × 6,000 μm 00053-28-2 300 μm × 300 μm × 6,000 μm 00053-28-3 300 μm × 300 μm × 6,000 μm
Example 17: Analysis of Difluprednate Content
[0322] The difluprednate concentration of the implants was determined via detection of using HPLC as described in Example 5. The mass of individual implants was also determined. Table 17 details the test results for the implants fabricated in Example 16.
TABLE-US-00017 TABLE 17 Difluprednate Content for Implants Difluprednate, μg Overall Implant, μg Difluprednate ID AVE STDEV % RSD AVE STDEV % RSD % 00053.23-1 90.6 2.9 3.3 203.7 6.5 3.2 44.5 00053-23.2 93.7 4.2 4.4 227.6 11.5 5.1 41.2 00053-23-3 92.0 0.9 1.0 228.2 1.3 0.6 40.3 00053-23-4 51.1 1.1 2.1 218.4 1.5 0.7 23.4 00053-23-5 89.0 2.9 3.3 234.9 3.9 1.7 37.9 00053-23-6 91.8 2.5 2.7 245.3 2.9 1.2 37.4 00053-28-1 215.9 15.3 7.1 812.4 80.2 9.9 26.6 00053-28-2 384.3 12.0 3.1 821.4 22.2 2.7 46.8 00053-28-3 385.7 32.1 8.3 818.8 64.5 7.9 47.1
Example 18: Implants Utilized for In Vivo Studies
[0323] A twenty-four day in vivo study utilizing New Zealand White Rabbits was conducted to determine the ocular tolerability and effect on induced inflammation over the course of the study for a select group of samples in Example 9. Table 18 details the IDs of the implants, number of implants utilized for dosing, and number of eyes dosed for the studies. Tables in the previous examples provide information as to composition and dimension for the implants. Topical administration of DUREZOL® (difluprednate ophthalmic emulsion) (Alcon Laboratories, Inc.) was used as a positive control. The dosing paradigm for the positive control was one drop per eye, four times daily for the duration of the study. For a negative control the surgery was conducted and a placebo implant containing no difluprednate was inserted.
[0324] Implants were placed subconjunctivally as described in Example 9. Two models were evaluated: paracentesis and corneal incision. In the paracentesis model, approximately 100 μL aqueous humor was withdrawn from samples on days 2 and 6. In the corneal incision model, 100 μL aqueous humor was withdrawn from samples on day 2. Additionally, corneal incision model groups had a 2.7 mm incision in the superior cornea sutured with 8-0 or 9-0 Vicryl on day 2.
[0325] The Total Ocular Exam Score was also scored as described in Example 9. All corneal incision groups had any scoring related to inflammation surrounding sutures omitted from the Ocular Safety Index.
TABLE-US-00018 TABLE 18 In Vivo Implants Implants Eyes Therapeutic Agent Therapeutic Agent Dosed/Eye Dosed Content/Implant Total Content/Dose ID # # μg μg Placebo Implant 2 6 0 0 Positive Control (Topical) 0 6 50 200 Positive Control (Injected) 0 6 50 50 53-23-5 2 6 105 210 53-28-1 2 6 216 432 53-28-2 3 6 384 1152 53-28-3 3 6 386 1158 53-4-8 2 6 556 1112
Example 19: ENV905 Difluprednate Ophthalmic Implant Studies
[0326] The present example demonstrates an embodiment of the disclosure, termed ENV905, which is a difluprednate ophthalmic implant for the treatment of inflammation and pain associated with ocular surgery.
[0327] ENV905 (difluprednate) ophthalmic implant is an injectable difluprednate implant formulation using a biocompatible polyethylene glycol (PEG)-based drug delivery system. The implant is designed for ophthalmic administration via subconjunctival (SCJ) or intracameral (IC) injection, with a single dose administered following ocular surgery targeting duration of action of 28 days. The PEG-based drug delivery system is comprised of a blend of two PEGs that function as both diluent and binder, and was designed for rapid dissolution of the implant and concurrent release of difluprednate following administration.
[0328] The bioavailability and sustained therapeutic effect of ENV905 over 28 days is governed by multiple factors, including route of administration and the physicochemical properties of the drug substance difluprednate.
[0329] The present example illustrates the functionality of various formulations of ENV905 ocular implants. Included in the various embodiments of ENV905 ocular implants tested are ENV905-1 (also designated by sample ID No. “115-8-7”) and ENV905-2 (also designated by sample ID No. “115-16-1”).
[0330] Each formulation was designed according to its intended route of administration, either IC (ENV905-1) or SCJ (ENV905-2). These two embodiments are designed to decrease ocular inflammation and pain for 28 days following a single administration via SCJ or IC injection, with the intended range of doses from approximately 40 to 80 μg (IC) or 400 to 800 μg (SCJ) difluprednate.
[0331] Characterization and Overview of ENV905
[0332] ENV905 is a biocompatible implant formulation containing the corticosteroid difluprednate in a PEG-based drug delivery system. ENV905 is formulated as a solid, rod-shaped implant of dimensions between 225-350 μm in width by 2,925-6,000 μm in length.
[0333] The aforementioned ENV905-1 formulation embodiment is designed for intracameral delivery into the anterior chamber of the eye. The IC implant ENV905-1 will enable targeted delivery of difluprednate directly into the anterior chamber, providing a potentially dose-sparing effect compared to DUREZOL®. The IC ENV905-1 implant was designed to rapidly disintegrate in the anterior chamber, providing a therapeutic effect over approximately 28 days.
[0334] The aforementioned ENV905-2 formulation embodiment is designed for implantation in the subconjunctival space. The SCJ implant ENV905-2 was designed to rapidly disintegrate in the subconjunctival space, providing a therapeutic effect over approximately 28 days. The two formulation embodiments differ in size and dose of difluprednate, while maintaining the same formulation characteristics of PEG excipients. The characteristics of these implants can be found, inter alia, in the below Tables 19 and 20.
TABLE-US-00019 TABLE 19 ENV905-1: Intracameral Ophthalmic Implant Formulation (Nominal Ranges) ENV905-1 Intracameral Implant Formulation Nominal Dimensions: 225 μm × 225 μm × 2,925 μm Amount Component/Property Function (μg/implant) % w/w Difluprednate Active 24 to 56 15 to 35 Total PEG (PEG 3,350 and Diluent/ 104 to 136 65 to 85 PEG 100,000) Binder PEG 3,350 11.4 to 15.0 7.2 to 9.4 PEG 100,000 92.6 to 121.0 57.9 to 75.7 Ratio of PEG 3,350/PEG 11%/89% w/w 100,000 Total Implant Mass — 128 to 192 —
TABLE-US-00020 TABLE 20 ENV905-2: Subconjunctival Ophthalmic Implant Formulation (Nominal Ranges) ENV905-2 Subconjunctival Implant Formulation Nominal Dimensions: 300 μm × 300 μm × 6,000 μm Amount Component/Property Function (μg/implant) % w/w Difluprednate Active 320 to 480 40 to 60 Total PEG (PEG 3,350 and Diluent/ 320 to 480 40 to 60 PEG 100,000) Binder PEG 3,350 35.2 to 52.8 4.4 to 6.6 PEG 100,000 284.8 to 427.2 35.6 to 53.4 Ratio of PEG 3,350/PEG 11%/89% w/w 100,000 Total Implant Mass — 640 to 960 —
TABLE-US-00021 TABLE 21 ENV905-3: Intracameral Ophthalmic Implant Formulation (Nominal Ranges) ENV905-3 Intracameral Implant Formulation Nominal Dimensions: 225 μm × 225 μm × 2,925 μm Amount Component/Property Function (μg/implant) % w/w Difluprednate Active 16 to 24 10 to 15 Total PEG (PEG 3,350 and Diluent/ 136 to 144 85 to 90 PEG 100,000) Binder PEG 3,350 15.0 to 15.8 9.4 to 9.9 PEG 100,000 121.0 to 128.2 75.7 to 80.1 Ratio of PEG 3,350/PEG 11%/89% w/w 100,000 Total Implant Mass — 152 to 168 —
TABLE-US-00022 TABLE 22 ENV905-4: Intracameral Ophthalmic Implant Formulation (Nominal Ranges) ENV905-4 Intracameral Implant Formulation Nominal Dimensions: 225 μm × 225 μm × 2,925 μm Amount Component/Property Function (μg/implant) % w/w Difluprednate Active 8 to 12 5.0 to 7.5 Total PEG (PEG 3,350 and Diluent/ 148 to 152 92.5 to 95.0 PEG 100,000) Binder PEG 3,350 16.3 to 16.7 10.2 to 10.5 PEG 100,000 131.7 to 135.3 82.3 to 84.6 Ratio of PEG 3,350/PEG 11%/89% w/w 100,000 Total Implant Mass — 156 to 164
TABLE-US-00023 TABLE 23 ENV905-5: Intracameral Ophthalmic Implant Formulation (Nominal Ranges) ENV905-5 Intracameral Implant Formulation Nominal Dimensions: 130 μm × 180 μm × 1,500 μm Amount Component/Property Function (μg/implant) % w/w Difluprednate Active 16 to 24 29.6 to 44.4 Total PEG (PEG 3,350 and Diluent/ 30 to 38 55.6 to 70.4 PEG 100,000) Binder PEG 3,350 3.3 to 4.2 6.1 to 7.7 PEG 100,000 26.7 to 33.8 49.4 to 62.6 Ratio of PEG 3,350/PEG 11%/89% w/w 100,000 Total Implant Mass — 46 to 62
[0335] ENV905 implants can be loaded into the needle of a single-use implant applicator and delivered directly into either the subconjunctival space or the anterior chamber. ENV905 was designed to deliver therapeutic levels of difluprednate for approximately 28 days in certain aspects.
[0336] ENV905 implants, of various configurations, have been well tolerated in efficacy and tolerability studies in albino rabbits following administration by their respective routes of delivery. This generalization will be supported by the below data.
[0337] Following subconjunctival insertion, ENV905-2 implants remain at the insertion site, cause no apparent discomfort, and rapidly disintegrate. Following IC insertion, ENV905-1 implants localize to the inferior iridocorneal angle upon insertion, remain largely immobile, and quickly disintegrate. ENV905 has been shown to decrease ocular inflammation in New Zealand white (NZW) rabbit models of post-operative inflammation, with excellent safety and tolerability profiles following both SCJ and IC administration.
[0338] Potential Mechanism of Action for ENV905 Embodiments
[0339] Without wishing to be bound to a particular mechanistic theory of action, the following description provides one possible mechanism of action for the ENVA905 ocular implants disclosed herein.
[0340] Corticosteroids inhibit the inflammatory response to a variety of inciting agents. They inhibit edema, fibrin deposition, capillary dilation, leukocyte migration, capillary proliferation, fibroblast proliferation, deposition of collagen, and scar formation associated with inflammation.
[0341] Corticosteroid activity is mediated by intracellular activation of GR. Binding of the corticosteroid ligand results in translocation of the ligand-bound GR from the cell cytosol into the nucleus, where it functions as a transcription factor and binds to the glucocorticoid response elements in the promoter regions of responsive genes or interacts directly with other transcription factors. The actions results in consequent anti-inflammatory effects due to down-regulation of pro-inflammatory molecule production.
[0342] In the eye, corticosteroids are thought to act by the induction of phospholipase A2 inhibitory proteins, collectively called lipocortins. It is postulated that these proteins control the biosynthesis of potent mediators of inflammation such as prostaglandins and leukotrienes by inhibiting the release of their common precursor arachidonic acid. Arachidonic acid is released from membrane phospholipids by phospholipase A2. Difluprednate is structurally similar to other corticosteroids (DUREZOL® Package Insert). DUREZOL® is a topical corticosteroid that is indicated for the treatment of inflammation and pain associated with ocular surgery as well as the treatment of endogenous anterior uveitis. DUREZOL® is formulated as a 0.05% difluprednate sterile preserved emulsion, and the treatment regimen is instillation of one drop into the conjunctival sac 4 times daily for 14 days, followed by a tapering regimen as clinically indicated.
[0343] The ENV905-1 and ENV905-2 embodiments can decrease ocular inflammation and/or pain for 28 days following a single administration via SCJ or IC injection, by effectively delivering difluprednate to targeted areas of the eye, rather than via the problematic topical application required for DUREZOL®.
[0344] Nonclinical Pharmacology of Difluprednate in Ocular Formulations
[0345] Difluprednate, a corticosteroid pro-drug of the active metabolite 6α,9-difluoroprednisolone 17-butyrate (DFB), is marketed as a 0.05% sterile preserved emulsion for topical ocular delivery. DUREZOL® is administered as a 4 times per day drop (approximately 100 μg per day) in patients recovering from ocular surgery or patients with endogenous anterior uveitis.
[0346] Corticosteroid eye drops have been in use since the 1950s for controlling ocular inflammation. Extensive clinical experience attests to the efficacy of these compounds for treating anterior segment inflammation (Gaudio 2004). Controlling inflammation is one of the key objectives following ocular surgery. Difluprednate is a potent corticosteroid that is regularly used by physicians following ocular surgery in the US standard of care. A glucocorticoid (GC) receptor-binding test was performed to evaluate GC receptor-binding activity (GCRBA) of glucocorticoids. Difluprednate's active metabolite DFB had the highest affinity for the GR with the lowest inhibition constant (K.sub.i) when compared with prednisolone, betamethasone, fluorometholone, and dexamethasone (Table 21) (Tajika 2011b). The greater binding affinity may be attributed to the unique molecular structure of difluprednate. Difluprednate is a derivative of prednisolone, but differs substantially due to structural modifications. The addition of two fluorines and a C-17 butyrate directly increase the affinity of difluprednate for the GR (Donnenfeld 2011).
TABLE-US-00024 TABLE 21 K.sub.i Values of Difluprednate, Its Metabolite, and Various Glucocorticoids Compound K.sub.i Value (mol/L) Difluprednate (DFBA) 7.8 × 10.sup.−10 ± 3.6 × 10.sup.−11 Desacetyl Difluprednate (DFB) 6.1 × 10.sup.−11 ± 1.2 × 10.sup.−11 Prednisolone 3.4 × 10.sup.−9 ± 7.3 × 10.sup.−10 Betamethasone 1.7 × 10.sup.−9 ± 3.2 × 10.sup.−10 Dexamethasone 1.9 × 10.sup.−9 ± 2.3 × 10.sup.−10
[0347] Studies of topical difluprednate in rabbits show that it is effective in models of post-operative inflammation when applied 4 times daily (QID; DUREZOL® NDA 22-212). Difluprednate has been studied in humans, and the efficacy and safety of topical ocular administration of DUREZOL® is established (Korenfeld 2009, Foster 2010).
[0348] Proposed Manufacturing Protocol of ENV905
[0349] Based upon the data contained in the present disclosure, the inventors anticipate large scale production of the ENV905 product. Both PEG 3,350 and PEG 100,000 will be manufactured in a current Good Manufacturing Practices (cGMP)-compliant process and comply with current National Formulary (NF) compendia specifications (USP 37-NF 32 Monographs for Polyethylene Glycol and Polyethylene Oxide). The ENV905 implant will be compounded and packaged in a low bioburden environment and may be terminally sterilized by gamma irradiation.
[0350] Description of Manufacturing Process and Process Controls for ENV905
[0351] Manufacture of ENV905 (difluprednate) ophthalmic implant is a well-controlled, multi-step process used to produce implants composed of micronized difluprednate contained within a biocompatible PEG drug delivery system.
[0352] The process begins with the fabrication and sterilization of the mold template that will be used to form the final implant geometry. The mold is formed by patterning a series of cavities into an ultraviolet (UV) curable polymer material. The resulting mold is a flexible sheet with an array of cavities of uniform size and shape. The mold sheet is then sterilized by gamma irradiation at Steris Isomedix, Inc. prior to use. A polyethylene terephthalate (PET) backing sheet used in the molding process is also sterilized by gamma irradiation at Steris Isomedix.
[0353] Micronized difluprednate is first compounded with the two PEGs at a specified ratio to create a homogeneous blend. The blend is then heated above the melting point of the PEGs to allow for the PEGs to freely flow creating a homogenous solid dispersion with the micronized difluprednate. The ENV905 (difluprednate) ophthalmic implant is then formed by thermally molding the resulting difluprednate/PEG blend into the desired geometrical shape using the pre-sterilized mold and backing sheet. This manufacturing step is performed in an International Standard for Organization (ISO) 5 environment. The final implant is prism-shaped with a size defined by the mold sheet cavities. The formed implants are then manually transferred in an ISO 5 environment into a pre-sterilized container closure. The packaged implants will then be terminally sterilized via gamma irradiation.
[0354] Implant Mold Fabrication
[0355] The final shape of the ENV905 (difluprednate) ophthalmic implant is defined by a molding process which uses a polymer mold template which consists of a polymer coating (referred to as SAE-04) that is applied to a backing sheet of PET. The SAE-04 material is a UV-curable silicone that can be patterned to form mold cavities in the desired shape and size of the implant.
[0356] The mold-making process begins with a master template fabricated on a silicon wafer through a process known in the microelectronics industry as photolithography. This master template consists of an array of uniformly sized and shaped features having nominally the same size and geometry as the final implant.
[0357] Through a series of replication steps referred to as mold making, the master template is then used to create a polymer mold template. First, the PET backing sheet is coated with a thin layer of an acrylate polymer to serve as an adhesive promoting tie-layer. This acrylate layer ensures that the SAE-04 mold adheres to the PET backing layer. Liquid SAE-04 monomer is premixed with a photo-initiator referred to as TMP (diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide) to drive the polymerization reaction during mold making. A small volume of SAE-04 solution is dispensed onto the PET backing sheet to form a film, and is covered with the master template. The sample is then exposed to UV light (λ.sub.avg=265 nm) for 60 to 120 seconds to polymerize the mold film while in contact with the pattern on the master template. This creates a series of rectangular cavities in the mold film. The solidified mold and PET backing layer are then peeled off of the master template to create a free-standing mold.
[0358] The mold is then inspected visually for macroscopic defects and mold cavity dimensions are verified using optical profilometry to measure the cavity depth. The mold is then double-bagged in self-sealing sterilization pouches and shipped to an external vendor for sterilization using gamma irradiation.
[0359] Preparation of Difluprednate/PEGs Blend for ENV905
[0360] All manufacturing procedures are performed at ambient temperature unless otherwise specified. Micronized difluprednate, PEG 3,350, and PEG 100,000 are all received as dry powders. The individual components are weighed and mixed at a given ratio. They are first thoroughly mixed as a dry powder blend by mechanical agitation. To ensure a homogenous blend, the dry powder blend is then heated above the melting points of the polymers. The polymers can then freely flow and form a homogeneous solid dispersion with the micronized difluprednate. The homogenous difluprednate/PEG blend solidifies as it cools down back to room temperature.
[0361] Preparation of Molded Implant
[0362] Individual implants are formed by heating the difluprednate/PEG blend and allowing it to flow into the cavities of the mold. Table 24 includes proposed processing parameters. This process takes place in two BSC hoods (ISO 5 environment). The difluprednate/PEG blend is placed on the PET sheet and placed on a hot plate for 120-180 seconds. Once heated, the blend is covered with the Fluorocur® (FCR) mold sheet. Light pressure is applied using a hand roller to laminate the two sheets together. The mold/blend laminate is then passed through a commercially available thermal laminator at a specified temperature, speed, and pressure. Under these conditions the difluprednate/PEG blend is able to flow into the mold cavities, filling the cavities, and assuming the shape of the mold cavities. The laminate containing the difluprednate/PEG blend in the mold cavities is then allowed to cool back down to room temperature. The difluprednate/PEG blend then solidifies forming individual, discrete implants. The mold can then be removed, leaving a two-dimensional array of discrete implants on the PET film.
TABLE-US-00025 TABLE 24 ENV905 Implant Fabrication Conditions Process Parameter Proposed Range Hot Plate Temp (° C.) 120-160 Hot Plate Time (sec) 120-180 Laminator Temp (° F.) 260-320 Laminator Speed (ft/min) 0.1-1.sup. Laminator Pressure (psi) 40-80 Number of Lamination Passes 4-8 Cooling time (min:sec) NLT 3:00
[0363] Implant Packaging
[0364] It is envisioned that in an embodiment the packaging for the ENV905 implants will be a blister pack comprised of a thermoformed film with each well containing individual dosage units, foil or foil laminate lidding, and a pressure-seal coating. Individual implants will be manually removed from the PET backing sheet using stainless steel tweezers. Alternatively, sterile vials may be used. Each implant will be visually inspected for macroscopic defects before placing it in its final packaging. It is envisioned that the ENV905 implants will be preloaded into an ENV905 Implant Applicator, with the needle hub assembly of the Applicator functioning as a container closure for the implants.
[0365] Sterility Assurance
[0366] Terminal moist heat sterilization is not a viable method due to the fact that ENV905 is a solid dosage form designed to disintegrate in aqueous environments. Therefore, studies to evaluate gamma irradiation were conducted on early ENV905 formulations to determine if ionizing radiation was a viable option for a terminally sterilized drug product. ENV905 implants were exposed to gamma irradiation with a dose of 46 kGy per ISO 11137-2:2012 (Sterilization of Health Care Products—Radiation—Part 2: Establishing the Sterilization Dose). The implant formulations used for these studies consisted of a blend of difluprednate and PEGs. The compositions and sizes of the implant formulations used in the study are provided in Table 25 below.
TABLE-US-00026 TABLE 25 Difluprednate Implant Formulations (ENV-1I-115-8) Mean Implant Difluprednate PEG Ratio Formula- Dimensions Content (μg) SD % (PEG 3,350/ tion ID (μm) (n = 10) (μg) RSD PEG 100,000) ENV-1I- 225 × 225 × 97.2 2.6 2.7 q.s. ad 115-8-3 4,000 11%/89% ENV-1I- 225 × 225 × 74.1 1.3 1.7 q.s. ad 115-8-5 2,925 11%/89% ENV-1I- 225 × 225 × 38.9 1.0 2.5 q.s. ad 115-8-7 2,925 11%/89%
[0367] Implants were individually packaged in HPLC vials with air headspace and polytetrafluoroethylene (PTFE)-lined screw caps. Ten individual implants (n=10) were tested for difluprednate assay. The results are summarized in Table 26.
TABLE-US-00027 TABLE 26 Impact of Gamma Irradiation (46 kGy) on Difluprednate Assay on Difluprednate/PEG Implant Formulations Radia- Mean Difluprednate Diflu- tion Content prednate Degrada- Formula- Dose (μg/implant) SD Assay tion tion (kGy) (n = 10 implants) (μg) (% Area) (% Area) Neat API None — — 97.98 — 46 — — 97.13 0.85 Implant None 97.2 2.6 97.19 — ENV-1I- 46 101.2 5.5 96.80 0.39 115-8-3 Implant None 74.1 1.3 97.54 — ENV-1I- 46 73.1 5.1 97.01 0.53 115-8-5 Implant None 38.9 1.0 97.92 — ENV-1I- 46 40.1 1.4 97.31 0.61 115-8-7
[0368] Gamma irradiation under standard sterilization conditions (46 kGy) resulted in 0.39% to 0.61% degradation of difluprednate in the drug product, and 0.85% degradation of neat difluprednate.
[0369] The effect of gamma irradiation disintegration time and difluprednate content in media upon full disintegration of the implants was also evaluated. Implants were individually packaged in HPLC vials with air headspace and PTFE-lined screw caps. Five (n=5) implants were tested for difluprednate assay in the media after a prescribed time of 5 minutes to achieve full disintegration. The results are summarized in Table 27.
TABLE-US-00028 TABLE 27 Impact of Gamma Sterilization on In Vitro Difluprednate Disintegration Test. Disintegration Medium: 0.01M Phosphate Buffered Saline, 1% SDS; Temperature = 20° C. Mean Difluprednate Content Measured in Media upon Full Implant Disintegration Radiation Dose (μg/implant) SD Formulation (kGy) (n = 5 implants) (μg) ENV-1I-115-8-3 None 103.3 4.3 46 104.4 5.0 ENV-1I-115-8-5 None 73.2 3.3 46 72.4 4.8 ENV-1I-115-8-7 None 40.7 1.1 46 40.6 0.8
[0370] Gamma irradiation did not statistically impact the amount of difluprednate recovered in the media after full disintegration. Furthermore, gamma irradiation did not have an impact on the time required to achieve full disintegration in media (t≤5 minutes).
[0371] Based on these preliminary sterilization studies described above, the inventors contemplate that in some embodiments they will terminally sterilize ENV905 drug product using gamma irradiation. A sterility assurance level of 10.sup.−6 or better will be demonstrated for the developed cycle.
[0372] Raw Materials and Proposed Excipient Specifications for ENV905
[0373] The raw materials and proposed specifications for the PEG excipients used to manufacture ENV905 (difluprednate) implants are summarized in Tables 28-31 below. The PEG excipients will be in conformance with NF compendial specifications.
TABLE-US-00029 TABLE 28 List of Raw Materials for ENV905 Material Name (product number) Purpose Difluprednate Active Poly(ethylene glycol) Diluent 3,350 Poly(ethylene glycol) Diluent/Binder 100,000
TABLE-US-00030 TABLE 29 List of Raw Materials for Mold Fabrication Material Name (product number) Purpose Polyethylene terephthalate (PET), Substrate Backing Layer 5 mil (Melinex 453) SR9012 (tri-functional acrylate ester) Mold Tie Layer Component DPT; (Diphenyl(2,4,6- Mold Tie Layer trimethylbenzoyl) phosphine oxide/ Component 2-hydroxy-2-methylpropiophenone) Fluorocur-SAE-04; FCR Mold Resin Acrylated Polysiloxanes; Siloxanes Component and Silicones, di-Me, hydrogen terminated, reaction products with acrylic acid and 2-ethyl-2-[(2- propenyloxy)methyl]-1,3-propanol TMP; Diphenyl(2,4,6- FCR Mold Resin trimethylbenzoyl)phosphine oxide Component (CAS# 75980-60-8)
TABLE-US-00031 TABLE 30 Proposed Specifications for Poly(ethylene glycol); 3,350 MW Proposed Test Specification Method Description Physical Appearance White to off - white Visual powder Average Molecular 90.0 to 110.0% of Titrimetric (NF Weight nominal value Monograph) Residue on Ignition NMT 0.1% USP<281> Heavy Metals NMT 5 ppm USP<231> Free Ethylene Dioxide NMT 10 μg/g Headspace GC - FID (NF Monograph) Free 1,4-Dioxane NMT 10 μg/g Headspace GC - FID (NF Monograph) pH (5.0 g of Poly- 4.5 to 7.5 USP<791> ethylene Glycol in 100 mL of carbon dioxide-free water) Completeness and Color Colorless and Clear NF Monograph of Solution Viscosity 9 to 15 cPs (25% w/w, Viscometry H.sub.2O at 25° C.) Microbial Limits Total microbial count ≤2000 CFU/g USP<61> Yeasts and molds ≤200 CFU/g Tests for specified Absence of S. aureus, USP<62> microorganisms E. coli, Salmonella, P. aeruginosa
TABLE-US-00032 TABLE 31 Proposed Specifications for Poly(ethylene glycol); 100,000 MW Test Proposed Specification Method Description Physical Appearance White to off - white Visual (NF powder Monograph) Infrared Absorption Spectrum consistent with USP<197K> reference standard Viscosity 12 to 50 cPs (c = 5%, Viscometry H.sub.2O, at 25° C.) Heavy Metals NMT 10 ppm USP<231> Method II Silicon Dioxide NMT 3% NF Monograph Residue on Ignition Non-Silicon Dioxide NMT 2% NF Monograph Residue on Ignition Free Ethylene Dioxide NMT 0.001% Headspace GC - FID (NF Monograph) Loss On Drying NMT 1.0% USP<731> Microbial Limits Total microbial count ≤2000 CFU/g USP<61> Yeasts and molds ≤200 CFU/g Tests for specified Absence of S. aureus, USP<62> microorganisms E. coli, Salmonella, P. aeruginosa
[0374] Nonclinical Pharmacology of ENV905
[0375] Multiple pharmacology studies of various formulations of ENV905 have been conducted in albino rabbit models of ocular post-operative inflammation.
[0376] Animal models included corneal incision, lens phacoemulsification, and anterior chamber paracentesis. The effect of ENV905, placebo implant, or positive control DUREZOL® on induced ocular inflammation was assessed over approximately 1 month, and the results are discussed in this section.
[0377] The anti-inflammatory effects of topical difluprednate have been established, and the kinetics of the deacetylation of difluprednate to its active metabolite desacetyl difluprednate (DFB) in vivo are known (Tajika 2011a, Tajika 2011b).
[0378] However, the pharmacology of extended release SCJ or IC delivery of difluprednate has not been studied, although delivery of other corticosteroids to these compartments demonstrates a reduction in ocular inflammation (Croasdale 1999, Deileman 2011, Koval 2014).
[0379] Nonclinical Pharmacology of ENV905—General Experimental Protocol
[0380] Four non-Good Laboratory Practices (GLP) efficacy and tolerability studies of ENV905 formulations have been completed in NZW rabbits (Table 32).
[0381] On Day 1, animals received either a bilateral corneal incision, which mimics the incision encountered during cataract surgery (studies ENV905-PRE-003, ENV905-PRE-006, and ENV905-PRE-008), or lens phacoemulsification (study ENV905-PRE-004), and were given a single bilateral administration of ENV905 or placebo implant concurrent with the surgical procedure.
[0382] DUREZOL® administered topically 4 times per day starting at the time of surgery served as the positive control. The dosing paradigm for DUREZOL® was one drop per eye, four times daily for the duration of the study. For a negative control, the surgery was conducted and a placebo implant (difluprednate-free) was inserted.
[0383] Animals were observed for general tolerability endpoints, and received ophthalmic exams at regular intervals during the study. As these models generally induce ocular inflammation for a limited amount of time, additional inflammation induction in the form of paracentesis (removal of an aliquot of aqueous humor) were conducted at approximately weekly intervals to enable assessment of the duration of anti-inflammatory effect of ENV905.
[0384] Specifically, for the ENV905-PRE-006 study, anterior chamber paracentesis was conducted on Days 9, 15, and 22 to induce ocular inflammation. Eyes were examined on Days −2 (baseline), 2, 3, 4, 9, 10, 11, 15, 16, 17, 22, 23, and 24 by a board certified veterinary ophthalmologist and were graded using the Hackett and McDonald Ophthalmic Exam Scoring System. See, Hackett, R D and McDonald, T O. Ophthalmic Toxicology and Assessing Ocular Irritation. Dermatoxicology, 5.sup.th edition. Ed. F N Marzulli and H I Maibach. Washington, D.C.: Hemisphere Publishing Corporation. 1996; 299-305 and 557-566.
[0385] Multiple formulations of ENV905 have been assessed in the pharmacology studies, and both routes of administration, subconjunctival and intracameral, were employed (Tables 33-35).
[0386] Specifically, ENV905 implants were assessed for effect on induced ocular inflammation in NZW rabbits following a single SCJ or IC dose administration on Day 1 (Table 32 and 33). Custom implant applicators with 21 G to 27 G needles were used to administer the implants. Placebo implant formulations were used as negative controls, and DUREZOL® dosed QID throughout the study served as the positive control group.
[0387] Ocular inflammation was induced by one of two methods: a 2.7 mm clear corneal incision approximately 1 mm from the limbus; a phacoemulsification procedure involving a surgical 2.7 mm clear corneal incision at the superior limbus, a central curvilinear capsularexis, and removal of the lens cortex and nucleus by phacoemulsification and aspiration. Additionally, as the induced ocular inflammation was relatively short lived and in order to assess effect on inflammation at later time points, animals also received anterior chamber paracentesis at predetermined time points, involving a 30 G needle placed through the limbus and removal of aqueous humor, at pre-determined time points during each study. General tolerability endpoints included body weights and daily clinical observations. A board-certified veterinary ophthalmologist performed ophthalmic exams and McDonald-Shadduck scoring to assess ocular inflammation.
TABLE-US-00033 TABLE 32 Summary of Completed Pharmacology Studies of ENV905 Dura- No. of tion Animals/ Regulatory Study Model (Days) Species Group Status Number Corneal 24 NZW 2-4 Non-GLP ENV905- Incision and Rabbit PRE-003 Paracentesis 25 NZW 2-4 Non-GLP ENV905- Rabbit PRE-006 31 NZW 4 Non-GLP ENV905- Rabbit PRE-008 Phaco- 28 NZW 2-4 Non-GLP ENV905- emulsification Rabbit PRE-004 and Paracentesis
TABLE-US-00034 TABLE 33 ENV905 Formulations Tested in Pharmacology Studies in New Zealand White Rabbits ENV905 Implant Number of Total Dose (μg Route of Formulation ID PEG Ratio Dimensions (μm) Implants/Eye difluprednate/Eye) Administration Study Number ENV-1I-53-32-1 PEG 35K/PEG 100K (70/30) 300 × 300 × 6,000 2 0 SCJ ENV905-PRE-003 ENV-1I-53-23-5 PEG 35K/PEG 100K (70/30) 225 × 225 × 4,000 2 210 SCJ ENV905-PRE-003 ENV-1I-53-28-1 PEG 35K/PEG 100K (70/30) 300 × 300 × 6,000 2 432 SCJ ENV905-PRE-003 ENV-1I-53-28-2 PEG 35K/PEG 100K (70/30) 300 × 300 × 6,000 3 1,152 SCJ ENV905-PRE-003 ENV-1I-53-28-3 PEG 1,000K (100) 300 × 300 × 6,000 3 1,158 SCJ ENV905-PRE-003 ENV-1I-115-3 PEG 35K/PEG 100K (70/30) 225 × 225 × 4,000 2 0 SCJ ENV905-PRE-004 ENV-1I-115-4 PEG 35K/PEG 100K (70/30) 300 × 300 × 6,000 2 0 SCJ ENV905-PRE-004 ENV-1I-115-1 PEG 35K/PEG 100K (70/30) 225 × 225 × 4,000 2 202 SCJ or IC ENV905-PRE-004 ENV-1I-115-2 PEG 35K/PEG 100K (70/30) 300 × 300 × 6,000 1 or 3 413 or 1,239 SCJ ENV905-PRE-004 ENV-1I-115-8-10 PEG 100K/PEG 3,350 (89/11) 225 × 225 × 2,925 1 0 IC ENV905-PRE-006 ENV-1I-115-23-1 PEG 100K/PEG 3,350 (89/11) 300 × 300 × 6,000 1 0 SCJ ENV905-PRE-006 ENV-1I-115-8-3 PEG 100K/PEG 3,350 (89/11) 225 × 225 × 4,000 2 204 IC ENV905-PRE-006 ENV-1I-115-8-5 PEG 100K/PEG 3,350 (89/11) 225 × 225 × 2,925 1 74 IC ENV905-PRE-006 ENV-1I-115-8-7 PEG 100K/PEG 3,350 (89/11) 225 × 225 × 2,925 1 40 IC ENV905-PRE-006 ENV-1I-115-16-1 PEG 100K/PEG 3,350 (89/11) 300 × 300 × 6,000 1 390 SCJ ENV905-PRE-006 ENV-1I-115-37-1 PEG 100K/PEG 3,350 (89/11) 225 × 225 × 2,925 1 0 IC ENV905-PRE-008 ENV905-2I-178-20-4 PEG 100K/PEG 3,350 (89/11) 225 × 225 × 2,925 1 10 IC ENV905-PRE-008 ENV905-2I-178-20-1 PEG 100K/PEG 3,350 (89/11) 225 × 225 × 2,925 1 20 IC ENV905-PRE-008 ENV905-2I-0178-25 PEG 100K/PEG 3,350 (89/11) 225 × 225 × 2,925 1 44 IC ENV905-PRE-008
TABLE-US-00035 TABLE 34 Polymer Matrix/Therapeutic Agent Blend Ratio For ENV905-PRE-006 and ENV905-PRE-008 Implants Polymer Matrix Target, % Therapeutic PEG PEG Agent Study No. ID 100K 3350 Target, % ENV905- ENV-1I-115-8-10 89.0 11.0 0.0 PRE-006 ENV-1I-115-23-1 89.0 11.0 0.0 ENV-1I-115-8-3 44.5 5.5 50.0 ENV-1I-115-8-5 44.5 5.5 50.0 ENV-1I-115-8-7 66.75 8.25 25.0 ENV-1I-115-16-1 44.5 5.5 50.0 ENV905- ENV-1I-115-37-1 89.0 11.0 0 PRE-008 ENV905-2I-178- 89.0 11.0 8 20-4 ENV905-2I-178- 89.0 11.0 14 20-1 ENV905-2I-0178- 89.0 11.0 26.4 25
TABLE-US-00036 TABLE 35 Implants Administered in ENV905-PRE-006 and ENV905-PRE-008 No. Therapeutic Agent Therapeutic Therapeutic No. Implants Eyes Content/Implant Agent Dose/Eye Agent Dose/ Study No. ID Dosed/Eye Dosed (μg) (μg) Animal (μg) ENV905-PRE-006 Positive Control 0 8 0 0 0 ENV-1I-115-8-10 1 4 0 0 0 ENV-1I-115-23-1 1 4 0 0 0 ENV-1I-115-8-3 2 8 102.2 204.4 408.8 ENV-1I-115-8-5 1 8 74.3 74.3 148.6 ENV-1I-115-8-7 1 8 40.2 40.2 80.4 ENV-1I-115-16-1 1 8 390.3 390.3 780.6 ENV905-PRE-008 ENV-1I-115-37-1 1 8 0 0 0 ENV905-2I-178-20-4 1 8 10 10 20 ENV905-2I-178-20-1 1 8 20 20 40 ENV905-2I-0178-25 1 8 44 44 88
[0388] Nonclinical Pharmacology of ENV905—Results
[0389] Dose administration via the SCJ or IC route was conducted successfully, and there were no adverse findings related to the dosing procedure noted in any study. Ocular inflammation was successfully induced via corneal incision or phacoemulsification, as observed by ophthalmic exam, and clinical findings related to the surgical procedure included conjunctival hyperemia and chemosis, iritis, and aqueous and cellular flare; these findings generally decreased in severity by Day 7. Anterior chamber paracentesis was conducted at the predetermined time points, and induced findings similar in nature, but diminished in severity, compared with those observed following the surgical procedures. Positive control DUREZOL® dampened the inflammatory response following surgery or paracentesis as expected.
[0390] SCJ ENV905 Results
[0391] SCJ ENV905, dosed at approximately 400 μg of difluprednate per eye, reduced inflammation following corneal incision at a level similar or superior to that observed with QID DUREZOL® (100 μg difluprednate per day, assumes 50 μL/drop) (
[0392] Following the more invasive lens phacoemulsification surgery, SCJ ENV905 at ˜400 μg difluprednate per eye did not reduce inflammation at 24 and 48 hours post-surgery when compared with QID DUREZOL®, but was equivalent in efficacy to DUREZOL® at all other time points (
[0393] Note that DUREZOL® dosing was initiated at the time of surgery in all studies, contrary to the package label instructions which recommend beginning DUREZOL® administration 24 hours post-surgery. Additionally, sufficient difluprednate following subconjunctival administration was present following a single administration on Day 1 to enable reduction of inflammation via paracentesis at each subsequent induction time point through Day 24/28 (
[0394] IC ENV905 Results
[0395] IC ENV905, dosed as a single administration of either 10, 20, 40 or 44 μg of difluprednate via one implant per eye, decreased the level of induced inflammation following corneal incision in a manner which was similar or superior to that observed with QID DUREZOL® (˜100 μg difluprednate per day, assumes 50 μL/drop) at most time points throughout the 24-day or 31-day study period (
[0396]
[0397]
[0398]
[0399] ENV905 In Vivo Animal Model Test Conclusions
[0400] Data from the aforementioned non-GLP pharmacology studies of various formulations of ENV905 indicate that, whether administered via the SCJ or IC routes, ENV905 decreases ocular inflammation following ocular surgery in the rabbit, at dose levels ranging from 40 to 400 μg of difluprednate per eye. A similar effect is expected in humans.
[0401] No adverse effects were noted in any study, and the implants were well tolerated in this species.
[0402] A significant dose sparing effect was observed with both SCJ and IC ENV905, with excellent anti-inflammatory effects observed at doses of difluprednate that were significantly less than the dose of difluprednate via topical DUREZOL®.
[0403] Pharmacokinetics of ENV905
[0404] Pharmacokinetics (often abbreviated PK) is the pharmacological study of how an administered drug is absorbed, distributed, metabolized, and eliminated by the body. See, Rowland and Tozer, “Clinical Pharmacokinetics and Pharmacodynamics: Concepts and Applications,” 4.sup.th Ed., 2011, Lippincott Williams & Wilkins publishers, which is incorporated herein by reference in its entirety for all purposes.
[0405] Systemic and ocular PK was assessed as part of the ENV905 pharmacology studies discussed above and two ocular pharmacokinetic studies.
[0406] Matrixes included aqueous humor, cornea, trabecular meshwork, iris/ciliary body, bulbar conjunctiva, subconjunctival dose site (SCJ only), retina, and plasma. Ocular matrixes were analyzed for both the parent molecule, difluprednate (DFBA), as well as the active metabolite, desacetyl difluprednate (DFB). Plasma was analyzed for DFB only, as the conversion to the active metabolite occurs within the ocular tissue prior to systemic absorption. Systemic exposure to DFB was minimal and was generally below the limit of quantitation by Day 7. Concentrations of DFBA and DFB in ocular tissue were dose dependent as well as dependent on the route of administration.
[0407] Bioanalytical Methods
[0408] Bioanalytical methods for difluprednate (DFBA), the active metabolite (DFB), and their internal standard DFB-d.sub.6 were developed and qualified in albino rabbit matrixes by Intertek Laboratories (San Diego, Calif.) using liquid-liquid extraction and high performance liquid chromatography and tandem mass spectrometry (LC-MS/MS). Methods in rabbit aqueous humor, cornea, trabecular meshwork, iris/ciliary body, bulbar conjunctiva, subconjunctival dose site (SCJ only), retina, and plasma (DFB only) were qualified for range of reliable response, selectivity, carryover assessment, and precision and accuracy.
TABLE-US-00037 TABLE 36 ENV905 Formulations Tested for Pharmacokinetics in Tolerability, Pharmacology, and Pharmacokinetics Studies in New Zealand White Rabbits. ENV905 Number of Total Dose (μg Formulation Implant Implants/ difluprednate/ Route of Matrices ID PEG Ratio Dimensions (μm) Eye Eye) Administration Study Number Analyzed ENV-1I-115-3 PEG 35K/PEG 100K 225 × 225 × 4,000 2 0 SCJ ENV905-PRE- Aqueous Humor, (70/30) 004 Conjunctiva ENV-1I-115-4 PEG 35K/PEG 100K 300 × 300 × 6,000 2 0 SCJ ENV905-PRE- Aqueous Humor, (70/30) 004 Conjunctiva ENV-1I-115-1 PEG 35K/PEG 100K 225 × 225 × 4,000 2 202 SCJ or IC ENV905-PRE- Aqueous Humor, (70/30) 004 Conjunctiva ENV-1I-115-2 PEG 35K/PEG 100K 300 × 300 × 6,000 1 or 3 413 or 1,239 SCJ ENV905-PRE- Aqueous Humor, (70/30) 004 Conjunctiva ENV-1I-115-4 PEG 35K/PEG 100K 300 × 300 × 6,000 2 0 SCJ ENV905-PRE- Plasma (Placebo) (70/30) 005 ENV-1I-53-28-1.sup.1 PEG 35K/PEG 100K 300 × 300 × 6,000 2 432 SCJ ENV905-PRE- Plasma (70/30) 005 ENV-1I-115-2 PEG 35K/PEG 100K 300 × 300 × 6,000 2 826 SCJ ENV905-PRE- Plasma (70/30) 005 ENV-1I-115-8-10 PEG 100K/PEG 3,350 225 × 225 × 2,925 1 0 IC ENV905-PRE- Aqueous Humor (89/11) 006 ENV-1I-115-23-1 PEG 100K/PEG 3,350 300 × 300 × 6,000 1 0 SCJ ENV905-PRE- Aqueous Humor (89/11) 006 ENV-1I-115-8-3 PEG 100K/PEG 3,350 225 × 225 × 4,000 2 204 IC ENV905-PRE- Aqueous Humor (89/11) 006 ENV-1I-115-8-5 PEG 100K/PEG 3,350 225 × 225 × 2,925 1 74 IC ENV905-PRE- Aqueous Humor (89/11) 006 ENV-1I-115-8-7 PEG 100K/PEG 3,350 225 × 225 × 2,925 1 40 IC ENV905-PRE- Aqueous Humor (89/11) 006 ENV-1I-115-16-1 PEG 100K/PEG 3,350 300 × 300 × 6,000 1 390 SCJ ENV905-PRE- Aqueous Humor (89/11) 006 ENV905-1 PEG 100K/PEG 3,350 225 × 225 × 2,925 3 121.5 IC ENV905-ADME- Plasma Aqueous (89/11) 001 Humor, Cornea/TM, Iris/Ciliary Body, Conjunctiva, Retina ENV905-2 PEG 100K/PEG 3,350 300 × 300 × 6,000 3 1207.5 SCJ ENV905-ADME- Plasma Aqueous (89/11) 001 Humor, Cornea/TM, Iris/Ciliary Body, Conjunctiva, Retina ENV905-1 PEG 100K/PEG 3,350 225 × 225 × 2,925 1, 2, or 3 42.8, 85.6, or IC ENV905-ADME- Plasma Aqueous (89/11) 128.4 002 Humor, Cornea, Trabecular Meshwork, Iris/Ciliary Body, Conjunctiva, Retina ENV905-1 PEG 100K/PEG 3,350 225 × 225 × 2,925 1, 2, or 3 44, 88, or 132 IC ENV905-TOX- Plasma (89/11) 001
[0409] Plasma Concentration Data from Tolerability Study ENV905-PRE-005
[0410] Animals received a single, bilateral administration of SCJ ENV905 (432 or 826 μg difluprednate per eye) or placebo implant.
[0411] There was no detectable DFB in plasma from placebo animals (LLOQ 0.05 ng/mL).
[0412] Following subconjunctival administration of ENV905, DFB in plasma peaked on Day 2 (24 hours post-dose), with concentrations of 0.68 and 0.72 ng/mL for 432 and 826 μg difluprednate per eye (864 and 1,652 μg difluprednate per animal), respectively. See, Table 37.
[0413] Systemic exposure to DFB decreased rapidly through Days 4 and 7, and was undetectable at later time points. In comparison to a previously published study, DFB C.sub.max in plasma following topical DUREZOL® administration was approximately 10 ng/mL at 30 minutes post-dose (Tajika 2011a).
[0414] These data demonstrate decreased systemic exposure to DFB following ENV905 administration when compared with QID DUREZOL®.
TABLE-US-00038 TABLE 37 Concentration of DFB in Rabbit Plasma Following Subconjunctival ENV905 Concentration Formulation Study of DFB Study Number (μg DFBA) Day Parameter (ng/mL) ENV905-PRE- ENV1I-53-28-1 2 Mean 0.678 005 (432) SD 0.238 4 Mean 0.116 SD 0.0278 7 Mean BLQ SD NA 14 Mean BLQ SD NA 29 Mean BLQ SD NA ENV905-PRE- ENV1I-115-2 2 Mean 0.720 005 (826) SD 0.232 4 Mean 0.206 SD 0.0872 7 Mean 0.0415 SD 0.0542 14 Mean BLQ SD NA 29 Mean BLQ SD NA
[0415] Aqueous Humor Concentration Data from Pharmacology Studies
[0416] Aqueous humor (AH) was obtained in the pharmacology studies described above, as part of the inflammation induction method of anterior chamber paracentesis.
[0417] An approximately 100 μL sample was obtained by the veterinary ophthalmologist using a 30 G needle inserted at the limbus. Samples were analyzed for DFBA and DFB in studies ENV905-PRE-004 and ENV905-PRE-006. Sampling days varied slightly across studies due to ophthalmologist availability.
[0418] In ENV905-PRE-004, animals received a single bilateral administration of ENV905, and AH was sampled on Days 9, 21, and 28. SCJ ENV905 doses were 413 or 1,239 μg of difluprednate per eye, and the IC dose was 202 μg difluprednate per eye. There was no detectable DFBA or DFB in AH obtained from placebo animals. Following a dose of 413 μg of difluprednate per eye, DFB was detectable on Day 9 and below the lower limit of quantification (LLOQ) at later time points. Following the 1,239 μg difluprednate per eye dose, DFB was detectable at all time points through Day 28. See, Tables 38-39.
[0419] In ENV905-PRE-006, animals received a single bilateral administration of ENV905, and AH was sampled on Days 9, 15, and 24. The SCJ dose was 390 μg difluprednate per eye, and IC doses were 40 and 74 μg difluprednate per eye. There was no detectable DFBA or DFB in AH obtained from placebo animals. SCJ ENV905 demonstrated no detectable DFB on Day 9, but was detectable at low concentrations on Days 15 and 24. IC ENV905 had very few samples with detectable DFB concentrations, potentially due to sampling only on Day 9 or later, while robust efficacy was seen in all animals throughout following this route of dose administration. See, Tables 38-39.
TABLE-US-00039 TABLE 38 Concentration of DFBA and DFB in Rabbit Aqueous Humor Following Subconjunctival ENV905 Concentra- Concentra- tion of tion of Study Formulation Study Param- DFBA DFB Number (μg DFBA) Day eter (ng/mL) (ng/mL) ENV905- ENV-1I- 9 Mean BLQ 0.039 PRE-004 115-1 SD NA 0.088 (413) 21 Mean BLQ BLQ SD NA NA 28 Mean BLQ BLQ SD NA NA ENV905- ENV-1I- 9 Mean BLQ 0.138 PRE-004 115-1 SD NA 0.171 (1,239) 21 Mean BLQ 0.056 SD NA 0.112 28 Mean BLQ 0.0436 SD NA 0.0825 ENV905- ENV-1I- 9 Mean BLQ BLQ PRE-006 115-16-1 SD NA NA (390) 15 Mean BLQ 0.0368 SD NA 0.0735 24 Mean BLQ 0.0206 SD NA 0.0412
TABLE-US-00040 TABLE 39 Concentration of DFBA and DFB in Rabbit Aqueous Humor Following Intracameral ENV905 Concentra- Concentra- tion of tion of Study Formulation Study Param- DFBA DFB Number (μg DFBA) Day eter (ng/mL) (ng/mL) ENV905- ENV-1I- 9 Mean BLQ BLQ PRE-004 115-1 SD NA NA (202) 21 Mean BLQ BLQ SD NA NA 28 Mean BLQ BLQ SD NA NA ENV905- ENV-1I- 9 Mean BLQ BLQ PRE-006 115-8-7 SD NA NA (40) 15 Mean BLQ 0.0278 SD NA 0.0555 24 Mean BLQ BLQ SD NA NA ENV905- ENV-1I- 9 Mean BLQ BLQ PRE-006 115-8-5 SD NA NA (74) 15 Mean BLQ 0.0278 SD NA 0.0555 24 Mean BLQ 0.0143 SD NA 0.0287
[0420] Conjunctiva Concentration Data from Pharmacology Study ENV905-PRE-004
[0421] Conjunctiva samples were taken at study termination in ENV905-PRE-004 to gain an understanding of how much DFBA and DFB remained at 28 days post-dose.
[0422] The formulations assessed in this study are not fully representative of the clinical candidate formulations that are planned for continued development, as they differ in excipient content. There was no detectable DFBA or DFB in the placebo samples. Detectable DFBA and DFB was present in 2 out of 8 samples at 28 days following the 413 μg difluprednate implant, and 4 out of 8 samples at 28 days following 1,239 μg difluprednate implant. Analysis of conjunctiva for concentration of DFBA and DFB following dosing of the clinical candidate formulations of ENV905 has not been conducted. See, Table 40.
TABLE-US-00041 TABLE 40 Concentration of DFBA and DFB in Rabbit Superior Conjunctiva Following Subconjunctival ENV905 Concentra- Concentra- tion of tion of Study Formulation Study Param- DFBA DFB Number (μg DFBA) Day eter (ng/g) (ng/g) ENV905- ENV-1I- 28 Mean 292.6 .sup. 27380.sup.1 PRE-004 115-1 SD 827.3 77426 (413) ENV905- ENV-1I- 28 Mean 26900 .sup. 368878.5.sup.2 PRE-004 115-1 SD 56997 569916.1 (1,239) .sup.12 out of 8 samples were quantifiable, all other samples were BLQ .sup.24 out of 8 samples were quantifiable, all other samples were BLQ
[0423] Ocular and Systemic Concentration Data from Pharmacokinetic Study ENV905-ADME-001
[0424] Plasma samples were collected from all surviving animals on Days 1 (2 h), 2 (24 h), 4, 7, 14, 21, 28, 42, 56 and 84. Ocular tissues from two animals per group per time point were collected on Days 14, 28, 42, 56, and 84. Ocular matrixes collected included: aqueous humor, cornea (enriched with trabecular meshwork), iris/ciliary body, bulbar conjunctiva, subconjunctival dose site (SCJ only), and retina.
[0425] The formulations assessed in this study are representative of the clinical candidate formulations that are planned for continued development.
[0426] Plasma exposure to Desacetyl Difluprednate (DFB) following intracameral administration of ENV905-1 was noted at minimal concentrations on Days 1 and 2, and was not quantifiable by Day 4. See,
[0427] Following SCJ delivery of ENV905-2, plasma exposure to Desacetyl Difluprednate (DFB) was also minimal and was quantifiable at very low levels through Day 14. See,
TABLE-US-00042 TABLE 41 Concentration of DFB in Rabbit Plasma Following Intracameral or Subconjunctival ENV905 No. of Concentra- Formulation Im- tion of Study (μg DFBA/ plants/ Study Param- DFB Number Implant) Eye Day eter (ng/mL) ENV905- ENV905-1 3 1 (2 h) Mean 2.583 ADME-001 (40.5) SD 0.779 IC Delivery 2 (24 h) Mean 0.062 SD 0.049 ENV905- ENV905-2 3 1 (2 h) Mean 3.850 ADME-001 (402.5) SD 2.703 SCJ Delivery 2 (24 h) Mean 3.475 SD 6.387 4 Mean 0.493 SD 0.09 7 Mean 0.134 SD 0.044 14 Mean 0.017 SD 0.028
[0428] Following IC delivery of ENV905-1, there was no quantifiable exposure to Difluprednate (DFBA) except in 1 iris/ciliary body sample on Day 28. All other samples were below the limit of quantitation (BLQ). Exposure to Desacetyl Difluprednate (DFB) was minimal on Day 14 in bulbar conjunctiva, TM-enriched cornea, and iris/ciliary body, and was not quantifiable at Day 28, See,
[0429] Following SCJ delivery of ENV905-2, Difluprednate (DFBA) was quantifiable at the dose site and cornea through Day 56, and was noted in the aqueous humor and retina at early time points. Desacetyl Difluprednate (DFB) was observed at the dose site and cornea through Day 84, in the bulbar conjunctiva through Day 56, in the iris/ciliary body through Day 42, in the retina through Day 28, and in the aqueous humor at early time points. See,
[0430] Ocular and Systemic Pharmacokinetics from Pharmacokinetic Study ENV905-ADME-002
[0431] New Zealand White male rabbits (two per group per terminal time point) were given a single bilateral administration of one, two, or three ENV905 (difluprednate) Ophthalmic Implants (ENV905-1) via intracameral delivery. For ENV-905-1, the total dose delivered was 42.8, 85.6, or 128.4 μg difluprednate per eye and 85.6, 171.2, or 256.8 μg difluprednate per animal, for the one, two, or three implant groups, respectively. A separate group of animals were administered topical DUREZOL® according to the clinical standard of care paradigm for comparison purposes. DUREZOL® dose administration was conducted as follows: one drop per eye four times per day on Days 1-14, one drop per eye twice daily on Days 15-21, and one drop per eye once daily on Days 22-28, resulting in a total dose of up to 1925 μg difluprednate per eye and 3850 μg difluprednate per animal over the course of the study.
[0432] Plasma and ocular matrixes (aqueous humor, bulbar conjunctiva, cornea, trabecular meshwork, iris/ciliary body, and retina) were collected on Days 1 (2 hours post dose), 2 (24 hours post dose), 4, 7, 14, 21, 28, and 42, and analyzed for exposure to Difluprednate (DFBA) and the active metabolite Diacetyl Difluprednate (DFB). Samples for animals in the DUREZOL® group were obtained on the same days, but were always collected at 30 minutes following the last dose administration of the day, so as to capture the peak exposure following topical administration. Data from these studies are provided in Table 42, and in
[0433] Topical DUREZOL® and a single bilateral administration of one, two, or three ENV905-1 implants per eye were well tolerated in the male NZW rabbit in this study for 42 days. Exposure to parent DFBA and metabolite DFB following topical DUREZOL® administration according to the clinical standard of care (1925 μg/eye) was consistent in plasma (assessed for DFB only) and in ocular matrixes across the dosing period when measured at 30 minutes post-dose, with the greatest exposure to DFB being in the cornea and trabecular meshwork (AUC.sub.last 19996 and 15530 d*ng/g, respectively). Exposure to the active metabolite DFB following administration of one ENV905-1 implant per eye (42.8 μg/eye) was highest in iris/ciliary body (AUC.sub.last 13174 d*ng/g; See
TABLE-US-00043 TABLE 42 Pharmacokinetics from ENV905-ADME-002 Parent: Difluprednate (DFBA) Metabolite: Desacetyl Difluprednate (DFB) C.sub.max C.sub.last AUC.sub.last C.sub.max C.sub.last AUC.sub.last (ng/mL T.sub.max T.sub.1/2 (ng/mL T.sub.last (d*ng/mL (ng/mL T.sub.max T.sub.1/2 (ng/mL T.sub.last (d*ng/mL Test Article Matrix or g) (d) (d) or g) (d) or g) or g) (d) (d) or g) (d) or g) DUREZOL ® Plasma NA NA NA NA NA NA 0.41 2 NC 0.26 28 8.83 (up to 1925 Aqueous 2.43 4 10.2 0.01 28 5.24 64 1 NC 49.2 28 1047 μg/eye, 3850 Humor μg/animal) Bulbar 6.52 28 NC 6.52 28 66.5 379 1 1.8 0.11 42 6528 Conjunctiva Cornea 56.8 7 NC 7.81 28 310 810 28 NC 0.43 42 19996 Trabecular 11.4 7 8.9 2.11 28 100 765 1 NC 717 28 15530 Meshwork Iris/Ciliary 0.65 7 NC 0.65 7 2.64 118 4 NC 109 28 2683 Body Retina 33.4 4 6.3 2.78 28 160 87.5 4 NC 25.8 28 749 ENV905-1 Plasma NA NA NA NA NA NA 0.99 1 NC 0.99 1 0.495 (42.8 μg/eye, Aqueous 3595 1 NC 305 2 3131 3420 1 0.3 0.022 7 3323 85.6 Humor μg/animal) Bulbar 0.575 1 NC 0.551 2 0.85 106 1 1.9 0.37 14 135 Conjunctiva Cornea 641 1 0.2 0.088 4 609 11283 1 3.2 0.65 14 9329 Trabecular 544 1 NC 88.3 2 523 9435 1 0.5 0.23 14 8571 Meshwork Iris/Ciliary 58125 1 NC 30020 2 71599 13115 1 0.4 0.2 7 13174 Body Retina 30.1 1 NC 0.77 2 23.1 89.9 1 0.8 0.33 7 92.1 ENV905-1 Plasma NA NA NA NA NA NA 1.98 1 NC 0.1 2 1.62 (85.6 μg/eye, Aqueous 25065 1 NC 77 7 21679 9273 1 0.7 24 7 8621 171.2 Humor μg/animal) Bulbar 18.8 4 NC 18.8 4 49.1 377 1 1.2 4.76 7 447 Conjunctiva Cornea 4029 1 0.5 0.665 7 3815 22750 1 0.5 0.21 14 19984 Trabecular 4215 1 0.5 1.04 7 4934 18050 1 0.7 28 7 18695 Meshwork Iris/Ciliary 181650 2 1.4 0.43 21 361171 32275 1 0.6 37.9 7 38503 Body Retina 363 4 NC 363 4 409 137 1 NC 45.5 4 169 ENV905-1 Plasma NA NA NA NA NA NA 2.75 1 0.5 0.04 4 2.44 (128.4 μg/eye, Aqueous 46050 1 0.7 0.023 14 41629 11158 1 0.6 5.57 7 10427 256.8 Humor μg/animal) Bulbar 48.7 4 NC 0.098 21 175 233 1 0.9 1.63 7 716 Conjunctiva Cornea 5640 1 0.4 0.335 7 7777 39875 1 3.7 0.08 28 33262 Trabecular 16703 2 0.3 0.38 7 25656 24825 1 0.6 15.8 7 29174 Meshwork Iris/Ciliary 243775 1 1.3 1.13 28 460790 41700 1 0.7 0.09 28 49403 Body Retina 3011 4 NC 0.485 7 4508 222 4 0.8 0.83 7 764
[0434] Toxicology Summary for ENV905
[0435] Difluprednate, a corticosteroid prodrug of the active metabolite DFB, is marketed as a 0.05% sterile preserved emulsion for topical ocular delivery. DUREZOL® is administered as a 4 times per day drop (approximately 100 μg per day) in patients recovering from ocular surgery or patients with endogenous anterior uveitis. The toxicology profile of difluprednate was investigated under NDA 22-212. Effects noted in nonclinical studies of difluprednate included decreases in body weight and adrenal effects, were deemed to be due to the pharmacologic action of the molecule, and are well known glucocorticosteroid effects (DUREZOL® Package Insert).
[0436] The disclosed ENV905 (difluprednate) Ophthalmic Implant is an injectable difluprednate implant formulation using a biocompatible polyethylene glycol (PEG)-based drug delivery system. The implant is designed for ophthalmic administration via subconjunctival (SCJ) or intracameral (IC) injection, with a single dose administered following ocular surgery targeting duration of action of 28 days. The PEG-based drug delivery system is comprised of a blend of two PEGs that function as both diluent and binder, and was designed for rapid dissolution of the implant and concurrent release of difluprednate. The bioavailability and sustained therapeutic effect of ENV905 over 28 days is governed by multiple factors, including route of administration and the physicochemical properties of the drug substance difluprednate. ENV905 is formulated for the treatment of inflammation and pain associated with ocular surgery. ENV905 is formulated as a solid, rod-shaped implant of dimensions between 225-350 μm in width by 2,925-6,000 μm in length. The implants are loaded into the needle of a single-use implant applicator and delivered into either the subconjunctival space or the anterior chamber where they will quickly disintegrate.
[0437] As shown in Table 43, multiple formulations of ENV905 administered by either SCJ or IC insertion were assessed for tolerability in the pharmacology studies conducted in NZW rabbits described above. Tolerability endpoints included body weights, daily clinical observations, ophthalmic exams conducted by a board-certified veterinary ophthalmologist, and ocular observations during enucleation at sacrifice.
TABLE-US-00044 TABLE 43 ENV905 Formulations Tested in Tolerability and Toxicology Studies in New Zealand White Rabbits Implant ENV905 Dimensions Number of Total Dose (μg Route of Formulation ID PEG Ratio (μm) Implants/Eye difluprednate/Eye) Administration Study Number ENV-1I-115-4 PEG 35K/PEG 100K (70/30) 300 × 300 × 6,000 2 0 SCJ ENV905-PRE-005 (Placebo) ENV-1I-53-28-1.sup.1 PEG 35K/PEG 100K (70/30) 300 × 300 × 6,000 2 432 SCJ ENV905-PRE-005 ENV-1I-115-2 PEG 35K/PEG 100K (70/30) 300 × 300 × 6,000 2 826 SCJ ENV905-PRE-005 ENV905-1 PEG 100K/PEG 3,350 (89/11) 225 × 225 × 2,925 3 0 IC ENV905-PRE-008 Placebo ENV905-5 PEG 100K/PEG 3,350 (89/11) 130 × 180 × 1,500 3 0 IC ENV905-PRE-008 Placebo ENV905-5 PEG 100K/PEG 3,350 (89/11) 130 × 180 × 1,500 3 60 IC ENV905-PRE-008 ENV905-1 PEG 100K/PEG 3,350 (89/11) 225 × 225 × 2,925 3 0 IC ENV905-TOX-001 Placebo ENV905-1 PEG 100K/PEG 3,350 (89/11) 225 × 225 × 2,925 1, 2, or 3 44, 88, or 132 IC ENV905-TOX-001
[0438] There were no observed adverse effects following a single administration of ENV905 (range 40 to 1,239 μg difluprednate per eye) or placebo implant noted in any of the aforementioned pharmacology studies.
[0439] A non-GLP tolerability study of SCJ ENV905 was conducted in NZW rabbits. Male rabbits were administered a single bilateral SCJ insertion of ENV905 or placebo implant and were followed for 28 days. Tolerability endpoints included body weights, daily clinical observations, ophthalmic exams, and ocular histopathology at sacrifice. Ophthalmic exams and histopathology assessment were conducted by a board-certified veterinary ophthalmologist. ENV905 (0, 432, or 826 μg difluprednate per eye) was well tolerated in the NZW rabbit for 28 days, no adverse effects were noted, and no evidence of ocular toxicity in clinical or histologic observation was observed over 29 days. See, e.g.,
[0440] A non-GLP tolerability study of IC ENV905 was conducted in NZW rabbits. New Zealand White rabbits (4 males/group) were administered a single bilateral intracameral injection of three ENV905 active or placebo implants, or received a single bilateral intracameral injection without implants (sham), and were followed for 7 days. The eyes were examined on Days 0 (baseline), 1 (8 hours post-dose), and on Days 2 (˜24 hours post-dose), 3 (˜48 hours post-dose), 4, 5, 6, and 7 by a board-certified veterinary ophthalmologist for signs of inflammation using the Hackett-McDonald scoring system, and animals were observed daily. Central and inferior corneal thickness was measured using an ultrasonic pachymeter at baseline, approximately 8 hours post-injection, and on Days 2, 3, 4, 5, 6, and 7. See
[0441] A GLP toxicology study of IC ENV905 was conducted in NZW rabbits. Male and female rabbits received a single administration of ENV905-1 and its relevant placebo, and were followed for 42 days. Assessment of toxicity was based on mortality, clinical observations, qualitative food consumption, body weight, ophthalmic examinations (slit lamp biomicroscopy and indirect ophthalmoscopy), intraocular pressure (IOP) measurements, pachymetry, electroretinography (ERG; scotopic tests), and clinical and anatomic pathology. Blood samples were collected for toxicokinetic evaluations. Male and female rabbits were each given three ENV905-1 Placebo ophthalmic implants; or one, two, or three ENV905-1 (difluprednate) ophthalmic implants, each containing 44.0 μg difluprednate/implant in the right and left eyes via intracameral injection using ENV905-1 Applicators (dose levels of 44.0 (Low), 88.0 (Mid), or 132.0 (High) μg/eye). No test article-related clinical findings or effects on mortality, clinical observations, qualitative food consumption, body weight, or body weight change were noted. Ophthalmic findings and IOP changes in the active ENV905-1 groups were limited to clinically beneficial effects on the procedure-associated inflammation (See
[0442] Thus, the tolerability profile of ENV905 and placebo implant has been demonstrated in multiple non-GLP pharmacology studies, a single non-GLP tolerability study, and a single GLP toxicology study, and no findings have been observed to date that preclude the continued development of ENV905.
[0443] Known Toxicology of Difluprednate (DUREZOL®)
[0444] The toxicology profile of difluprednate was investigated under DUREZOL® NDA 22-212. In multiple studies performed in rodents and non-rodents, subchronic and chronic toxicity tests of difluprednate showed systemic effects such as suppression of body weight gain; a decrease in lymphocyte count; atrophy of the lymphatic glands and adrenal gland; and for local effects, thinning of the skin; all of which were due to the pharmacologic action of the molecule and are well known glucocorticosteroid effects. Most, if not all of these effects were reversible after drug withdrawal. The no-observed-effect-level (NOEL) for the subchronic and chronic toxicity tests were consistent between species and ranged from 1-1.25 μg/kg/day (DUREZOL® Package Insert).
[0445] Difluprednate was not genotoxic in vitro in the Ames test, and in cultured mammalian cells CHL/IU (a fibroblastic cell line derived from the lungs of newborn female Chinese hamsters). An in vivo micronucleus test of difluprednate in mice was also negative. Treatment of male and female rats with subcutaneous difluprednate up to 10 μg/kg/day prior to and during mating did not impair fertility in either gender. Long-term studies have not been conducted to evaluate the carcinogenic potential of difluprednate (DUREZOL® Package Insert).
[0446] Difluprednate is categorized as Pregnancy Category C. Difluprednate has been shown to be embryotoxic (decrease in embryonic body weight and a delay in embryonic ossification) and teratogenic (cleft palate and skeletal anomalies) when administered subcutaneously to rabbits during organogenesis at a dose of 1-10 μg/kg/day. The NOEL for these effects was 1 μg/kg/day, and 10 μg/kg/day was considered to be a teratogenic dose that was concurrently found in the toxic dose range for fetuses and pregnant females. Treatment of rats with 10 μg/kg/day subcutaneously during organogenesis did not result in any reproductive toxicity, nor was it maternally toxic. At 100 μg/kg/day after subcutaneous administration in rats, there was a decrease in fetal weights and delay in ossification, and effects on weight gain in the pregnant females (DUREZOL® Package Insert).
[0447] Known Toxicology of PEG Excipients
[0448] High molecular weight PEGs, also known as polyethylene oxide (PEO) are polymers of ethylene oxide with a formula of HO—(CH.sub.2—CH.sub.2—O).sub.n—H, where n is the number (average) of ethylene glycol groups present in the molecule.
[0449] PEGs are not single chemical entities, but are mixtures of various polymer chain lengths, and for some of the higher molecular weight materials they can also be branched (Morpurgo 2004).
[0450] PEG is commonly used in cosmetics, PEGylated biologics, and in numerous approved and marketed therapeutics (Inactive Ingredients Database). These polymers are largely excreted unchanged in the urine, with hepatobiliary clearance representing a relatively minor pathway (Webster 2009). PEGs have been used extensively in approved products across multiple routes of administration including oral, topical, ophthalmic, rectal, vaginal, intrasynovial, intra-articular, intramuscular, and intravenous. PEGs are generally considered to have low toxicity and have been tested across multiple routes of administration. PEGs with a wide range of molecular weights have been shown to be safe (Herold 1982, Smyth 1947, Smyth 1950, Smyth 1970, Webster 2009). However, significant systemic exposure to PEGs via some routes of administration (mainly topical application to burn victims) has resulted in renal toxicity (Herold 1982). Studies of intravenous PEG have shown that urinary clearance decreased with increasing PEG molecular weight, similar to the tissue clearance, whereas liver clearance increased with increasing PEG molecular weight (Yamaoka 1993). After intravenous, intramuscular, and subcutaneous administration, PEGs are generally excreted almost completely within 24 hours, mainly in the urine (M AK collection). Furthermore, intravenous administration of PEG 4,000,000 g/mol MW at dose levels of up to 10 mg/kg had no evident toxicological effect (Smyth 1970). PEGs are classified as Pregnancy Category C.
[0451] ENV905 ocular implant formulations may contain, in certain embodiments, approximately 11.4 or 52.8 μg of PEG 3,350 g/mol MW and 92.6 or 427.2 μg of PEG 100,000 g/mol MW per implant for the intracameral or subconjunctival implants, respectively.
[0452] Based on current thinking for the proposed dose levels in the GLP toxicology studies (up to 4 implants dosed bilaterally, if feasible), animals could receive up to 422.4 μg PEG 3,350 and 3,417.6 μg PEG 100,000 per animal, while the exposure in the placebo implant groups could be as much as twice that as the placebo implants will be equal in mass to the ENV905 implants but will not contain active pharmaceutical ingredient (API).
[0453] Systemic exposure to molecules administered via the IC or SCJ routes is generally minimal, although exposure to PEG using these routes is unknown. Clinical pathology parameters, including renal factors BUN and creatinine, as well as liver enzyme levels, will be measured predose and at sacrifice in all animals in the GLP toxicology study to assess the effect of potential systemic exposure to PEG; gross pathology at necropsy and organ weights will also be monitored. Systemic histopathology is not planned.
[0454] ENV905 Implant Applicator
[0455] In embodiments, the ENV905 ocular implant administrations have been performed using an ENV905 implant applicator; this sterile applicator is comprised of either a 21 G to 22 G (for ENV905-2), or a 25 G to 27 G (for ENV905-1, ENV905-3, ENV905-4, and ENV905-5) single-lumen hypodermic needle and stainless steel pushrod attached to a standard 1-mL syringe.
[0456] ENV905 implants can be injected using the ENV905 ocular implant applicator into the subconjunctival space or anterior chamber of the eye using said injection tool.
[0457] The sterile implant applicator and the sterile ENV905 implants, in some aspects, can be packaged separately and loaded in a sterile field in an operating room prior to administration to patients scheduled for cataract surgery.
[0458] In some embodiments, ENV905 implants will be preloaded into the sterile applicator, with the needle hub assembly of the implant applicator functioning as a container closure for the implants.
[0459] ENV905 Implant Applicator Design
[0460] In embodiments, the applicator will be supplied as a single-use, sterile, needle-based instrument for delivery of the ENV905 implants into the subconjunctival space or anterior chamber. In aspects, the applicator can utilize a 510K-approved, 21 G, 22 G, 23 G, 24 G, 25 G, 26 G, or 27 G, single-lumen hypodermic needle to deliver the ENV905 implant(s). A stainless steel metal shaft actuated via scroll wheel will advance the rod-shaped ENV905 implants from the lumen of the needle. The ENV905 implant applicator, in some embodiments, will be terminally sterilized via gamma irradiation following assembly and packaging. In some aspects, the ENV905 implant applicator will be packaged in a Tyvek™ pouch and terminally sterilized via gamma irradiation in accordance with a validated sterilization method.
Prophetic Example 1: ENV905 in Cataract Surgery
[0461] The following example is prophetic in nature and describes experiments to be performed and predicted results, rather than work actually conducted or results actually achieved. Clinical efficacy and safety is evaluated in randomized, active comparator controlled study in which subjects after cataract extraction followed by intraocular lens implantation are treated with DUREZOL (difluprednate ophthalmic emulation 0.05%) or ENV905 containing smaller dose of difluprednate vs. what is administered to the patient via DUREZOL over the treatment period of 4 weeks after the surgery. DUREZOL is administered as indicated 4 times daily beginning 24 hours after surgery and continuing throughout the first 2 weeks of the postoperative period, followed by 2 times daily for a week and then a taper based on the response. The presence of complete clearing (a cell count of 0) is assessed 8 and 15 days post-surgery. All adverse events are tracked and evaluated, including adverse event of intraocular pressure (IOP) elevation. The primary efficacy results based on presence of complete clearing as described above show non-inferior control of ocular inflammation in patients dosed with ENV905.
[0462] The adverse event of IOP elevation is often characterized as IOP elevation by more than 10 mmHg. It has been shown for DUREZOL that the adverse event of IOP elevation occurs approximately in the range of 5-10% percent of the patients. ENV905, while demonstrating non-inferior treatment effect, will demonstrate improved safety and lesser incidence of adverse event of IOP elevation over DUREZOL's incidence of 5-10%. Thus, it is expected that the incidence of adverse events of IOP elevation is lower in patients dosed with ENV905 compared to patients dosed with DUREZOL.
Prophetic Example 2: ENV905 in Endogenous Anterior Uveitis
[0463] The following example is prophetic in nature and describes experiments to be performed and predicted results, rather than work actually conducted or results actually achieved. Clinical efficacy and safety is evaluated in randomized, active comparator controlled study in which subjects who present with endogenous anterior uveitis are assigned to DUREZOL (difluprednate ophthalmic emulation 0.05%) or ENV905 containing smaller dose of difluprednate vs. what is administered to the patient via DUREZOL over the treatment period. DUREZOL is administered as indicated 4 times daily continuing throughout 2 weeks. The presence of complete clearing (a cell count of 0) is assessed at 8 and at 15 days. All adverse events are tracked and evaluated, including adverse event of intraocular pressure (IOP) elevation. The primary efficacy results based on presence of complete clearing as described above show non-inferior control of ocular inflammation in patients dosed with ENV905.
[0464] The adverse event of IOP elevation is often characterized as IOP elevation by more than 10 mmHg. It has been shown for DUREZOL that the adverse event of IOP elevation occurs approximately in the range of 5-10% percent of the patients. ENV905, while demonstrating non-inferior treatment effect, will demonstrate improved safety and lesser incidence of adverse event of IOP elevation over DUREZOL's incidence of 5-10%. Thus, it is expected that the incidence of adverse events of IOP elevation is lower in patients dosed with ENV905 compared to patients dosed with DUREZOL.
TABLE-US-00045 LIST OF ABBREVIATIONS Abbreviation Definition % RSD relative standard deviation % v/v % volume/volume % w/w % weight/weight ° C. degrees Celsius ° F. degrees Fahrenheit μg microgram μL microliter μm micrometer λ.sub.avg average wavelength AH aqueous humor API active pharmaceutical ingredient AUC.sub.last area under the plasma concentration-time curve from time zero to the time of the last quantifiable concentration BCVA best corrected visual acuity BID twice daily BLQ below limit of quantitation BSC biological safety cabinet c concentration CAS # chemical abstracts service number CDER Center for Drug Evaluation and Research CFU colony-forming unit cGMP current Good Manufacturing Practices C.sub.max maximal concentration CMC chemistry, manufacturing, and controls cPs centipoise Da daltons DFB 6α,9-difluoroprednisolone 17-butyrate (desacetyl difluprednate) DFBA 6α,9-difluoro-11β,17,21-trihydroxypregna-1,4-diene- 3,20-dione 21 acetate 17-butyrate (difluprednate) DMF Drug Master File DPT (diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide/2- hydroxy-2-methylpropiophenone) DTOP Division of Transplant and Ophthalmology Products ETDRS Early Treatment Diabetic Retinopathy Study EU endotoxin units FCR Fluorocur ® (mold) FDA United States Food and Drug Administration FID flame ionization detector ft foot FTIR Fourier transform infrared spectrometry g gram G gauge GC gas chromatography GLP Good Laboratory Practices GR glucocorticoid receptor GCRBA glucocorticoid receptor-binding activity H half HPLC high performance liquid chromatography HPLC RT high performance liquid chromatography retention time IC intracameral ICH International Conference on Harmonization IND Investigational New Drug IOP intraocular pressure ISO International Standard for Organization K thousand (number) kGy kilogray K.sub.i inhibition constant L liter l.c. label claim LC-MS/MS liquid chromatography and tandem mass spectrometry LLOC lower limit of quantification M molar ME masked extension mg milligram min minute mm millimeter MTD maximum tolerated dose MW average molecular weight N, n, or No. number NA not applicable NDA New Drug Application NF National Formulary ng nanogram NLT not less than nm nanometer NMT not more than NOEL no-observed-effect-level NZW New Zealand white (rabbit) PD pharmacodynamic PEG polyethylene glycol PEO polyethylene oxide PET polyethylene terephthalate PK pharmacokinetic ppm parts per million psi pounds per square inch PTFE polytetrafluoroethylene q.s. ad quantities sufficient to make QC quality control QID four times daily RH relative humidity RT retention time SAE-04 mold resin component SCJ subconjunctival SD standard deviation SDS sodium dodecyl sulfate sec seconds T or t time TBD to be determined T.sub.max time of C.sub.max TMP diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide US United States USP United States Pharmacopoeia USP-NF United States Pharmacopoeia - National Formulary UV ultraviolet VA visual acuity
TABLE-US-00046 SUMMARY OF EMBODIMENTS OF OCULAR IMPLANT FORMULATIONS AI in AI in PEG % w/w in Total Dimension of Volume of implant implant PEG (μg) in implant implant implant Needle implant implant (μg) (% w/w) (3,350/100,000) (3,350/100,000) (μg) (ga) ENV905-1 225 × 225 × 2925 148,078,125 24-56 15-35 104-136 65-85 128-192 27 (11.4-15.0/92.6-121.0) (7.2-9.4/57.9-75.7) ENV905-3 16-24 10-15 136-144 85-90 152-168 (15-15.8/121-128.2) (9.4-9.9/75.7-80.1) ENV905-4 8-12 .sup. 5-7.5 148-152 92.5-95.0 156-164 (16.3-16.7/131.7-135.3) (10.2-10.5/82.3-84.6) ENV905-2 300 × 300 × 6000 540,000,000 320-480 40-60 320-480 40-60 640-960 21, 22 (35.2-52.8/284.8-427.2) (4.4-6.6/35.6-53.4) ENV905-5 130 × 180 × 1500 35,100,000 16-24 29.6-44.4 30-38 55.6-70.4 46-62 25, 26, 27 (3.3-4.2/26.7-33.8) (6.1-7.7/49.4-62.9)
INCORPORATION BY REFERENCE
[0465] All references, articles, publications, patents, patent publications, and patent applications cited herein, are hereby incorporated by reference in their entireties for all purposes.
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