Systems and methods for delivery of a therapeutic agent
11666526 · 2023-06-06
Assignee
Inventors
Cpc classification
A61M37/00
HUMAN NECESSITIES
A61K9/0021
HUMAN NECESSITIES
A61N5/10
HUMAN NECESSITIES
A61K41/0028
HUMAN NECESSITIES
A61N1/327
HUMAN NECESSITIES
C12Y304/24069
CHEMISTRY; METALLURGY
A61K2300/00
HUMAN NECESSITIES
A61K2300/00
HUMAN NECESSITIES
A61K41/0047
HUMAN NECESSITIES
A61B2018/1861
HUMAN NECESSITIES
A61M37/0092
HUMAN NECESSITIES
A61K41/00
HUMAN NECESSITIES
Y02A50/30
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
A61B18/1492
HUMAN NECESSITIES
A61B2018/0016
HUMAN NECESSITIES
A61B2018/00214
HUMAN NECESSITIES
A61N1/08
HUMAN NECESSITIES
International classification
A61B18/18
HUMAN NECESSITIES
A61K38/16
HUMAN NECESSITIES
A61K41/00
HUMAN NECESSITIES
A61K9/00
HUMAN NECESSITIES
A61M37/00
HUMAN NECESSITIES
A61N1/08
HUMAN NECESSITIES
A61N1/30
HUMAN NECESSITIES
A61N5/10
HUMAN NECESSITIES
Abstract
Methods and apparatus are provided for applying an fragment of a neurotoxin such as the active light chain (LC) of the botulinum toxin (BoNT), such as one of the serotype A, B, C, D, E, F or G botulinum toxins, via permeabilization of targeted cell membranes to enable translocation of the botulinum neurotoxin light chain (BoNT-LC) molecule across the targeted cell membrane to the cell cytosol where a therapeutic response is produced in a mammalian system. The methods and apparatus include use of catheter based delivery systems, non-invasive delivery systems, and transdermal delivery systems.
Claims
1. A nerve modification device for altering nerve function in a bronchial airway of a patient, the nerve modification device comprising: a main catheter body configured to extend through a trachea into the bronchial airway; a first electrode coupled to a distal end of the main catheter body, the first electrode being configured to be positioned proximate a target region in an airway wall of the bronchial airway and to emit energy laterally relative to the main catheter body; a second electrode configured to be positioned outside of the bronchial airway and remote from the target region; and a movable mechanism configured to move the first electrode laterally within the bronchial airway such that the at least one energy emitter contacts a first portion of a circumference of the airway wall, wherein the nerve modification device is adapted to produce an energy field between the first electrode and the second electrode and concentrated at the target region in the wall of the bronchial airway in a first lateral direction from the catheter body to alter nerve cells within the target region, and wherein a size and intensity of the energy field is controllable by placement of the first and second electrodes relative to each other and the target region.
2. The nerve modification device of claim 1, wherein the energy is at least one of x-ray energy, radiofrequency energy, DC current, AC current, microwave energy, and ultrasound energy.
3. The nerve modification device of claim 2, wherein the energy is RF energy.
4. The nerve modification device of claim 1, wherein the first electrode comprises at least one ultrasound transducer.
5. The nerve modification device of claim 4, wherein the energy is ultrasound energy.
6. The nerve modification device of claim 1, wherein the movable mechanism comprises an expandable member coupled to the main catheter body, the expandable member being configured to expand to move the first electrode into contact with the first portion of the circumference of the wall.
7. The nerve modification device of claim 6, wherein the expandable member is further configured to expand such that the expandable member engages a second portion of the circumference of the airway wall.
8. The nerve modification device of claim 7, wherein the expandable member is expanded laterally in a second lateral direction from the catheter body opposite the first lateral direction.
9. A system for altering nerve function in a bronchial airway of a patient, the system comprising: an intraluminal catheter configured to be positioned within a bronchial airway of a patient, the intraluminal catheter including a main catheter body, and a first electrode configured to be positioned within the bronchial airway proximate a target region in the airway wall, and to emit energy laterally relative to the main catheter body; a movable mechanism coupled to a distal end of the main catheter body, and configured to move the first energy emitter laterally within the bronchial airway such that the first energy emitter contacts a first portion of a circumference of the airway wall; a second electrode configured to be positioned remote from the target region; and an energy generator operably coupled to the first electrode and configured to activate the first electrode, thereby causing an energy field to be generated the target region in the airway wall to alter nerve cells within the target region, and wherein a size and intensity of the energy field is controllable by placement of the first and second electrodes relative to each other and the target region.
10. The system of claim 9, wherein the second electrode is operably coupled to the energy generator, and coupled to the movable mechanism relative to the first electrode such that an arrangement of the first and second electrodes causes the energy field produced therefrom to be concentrated in a lateral direction from the main catheter body.
11. The system of claim 9, wherein the second electrode is operably coupled to the energy generator, and coupled to the movable mechanism relative to the first electrode such that an arrangement of the first and second electrodes causes the energy field produced therefrom to comprise a uniform energy field about the main catheter body.
12. The system of claim 9, wherein the movable mechanism comprises an expandable member coupled to the mam catheter body, the expandable member being configured to expand to move the first electrode into contact with a first portion of a circumference of the airway wall.
13. The system of claim 12, wherein the expandable member is further configured to expand such that the expandable member engages a second portion of the circumference of the airway wall.
14. The system of claim 9, wherein the energy is at least one of x-ray energy, radiofrequency energy, DC current, AC current, microwave energy, and ultrasound energy.
15. The system of claim 14, wherein the energy is RF energy.
16. The system of claim 9, wherein the second electrode is configured to be positioned outside of the bronchial airway.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Further features of the invention, its nature and various advantages will be more apparent from the accompanying drawings and the following detailed description, in which:
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
(13)
(14)
(15)
(16)
(17)
(18)
(19)
DETAILED DESCRIPTION OF THE INVENTION
(20) The present invention is directed to methods and apparatus for targeting the non toxic delivery of a fragment of a neurotoxin, while still maintaining the catalytic or toxic effect of the neurotoxin fragment once it is non-toxically delivered to its targeted cell. For purposes of this specification, the term “non-toxic”, “non-toxically” and the like refer to the state of the fragment molecule prior to delivery to a target location. In this description, the fragment neurotoxin is intended to retain its toxic effect once delivered to its catalytic environment; the intracellular matrix or cytosol of the targeted cell.
(21) Devices and methods of the present invention may be directed to suitable “targeted regions” such as muscle cells in various regions of the body related to the various “therapeutic target conditions” or syndromes to be treated, as detailed in this specification above. Some particular examples include targeting mucosal and muscular lining of the lung, cholinergic cells in the region of tumors, myofacial regions, vascular smooth muscle cells, musculoskeletal regions and the like.
(22) According to the present invention, energy fields (EF) may be applied to target regions in conjunction with the delivery of a fragmented neurotoxin such as BoNT-LC to facilitate the transfer of the neurotoxin fragment into the targeted cell, non-toxically via in vivo target cell permeabilization.
(23) Use of Isolated Light Chain of Botulinum Neurotoxins
(24) Generally, the BoNT molecule is synthesized as a single polypeptide chain of 150 kD molecular weight. The neurotoxin is then exposed to enzymes, either during cultivation of the Clostridium botulinum organism or subsequent to purification of the toxin, wherein specific peptide bonds are cleaved or “nicked” resulting in the formation of a dichain molecule referred to as BoNT. As shown in
(25) Over the past several years, the separation and purification of the light chain and heavy chain of BoNT has seen significant development activity. In the case of the heavy chain (HC), researchers are interested in its ability to bond with a target cell and deliver certain molecules into that cell. For example, various drug delivery applications have been suggested, for example, using the HC to bind to tPA so that a patient could inhale the HC bound tPA allowing it to cross the membrane of the lungs and be transported into the bloodstream for anticoagulation. Of particular interest to the present invention are the efforts to isolate and purify the light chain (LC) of the botulinum molecule. In its isolated and purified form, all HC elements are removed, rendering the LC incapable of crossing the cell membrane without assistance. Thus, the LC is non-toxic until delivered to the target cell cytosol by the delivery protocols of the present invention.
(26) Various groups have been active in the area of isolation and purification. For example, companies such as Metabiologics, a group affiliated with the University of Wisconsin, the Center for Applied Microbiology and Research (CAMR), a division of the UK Health Protection Agency, List Biological Laboratories, Inc. of California, and other research groups throughout the world. Many of these companies provide purified preparations of botulinum neurotoxins from Clostridium botulinum types A and B. List Laboratories in particular provides recombinantly produced light chains from both types A, B, C, D and E.
(27) According to the present invention, the therapeutic use and delivery of the light chain only may significantly improve the safety profile of certain applications of therapies utilizing BoNT. BoNT are some of the most lethal toxins known to man. All concerns about migration of the neurotoxin into unintended regions, and harm or toxicity to the patient or physician are eliminated by storing, handling, injecting and metabolizing the light chain only. In the absence of a specific membrane binding technology, the LC is completely non-toxic. In certain applications, such as the treatment of asthma, this is of critical import. In using BoNT to treat asthma, a large quantity of the purified LC substance may be introduced directly into the lung, and then specifically transported to target cells in the exact location and only during the period of use of application of the membrane transport technology, such as cell membrane permeabilization by energy. Once the membrane transport technology has been removed, turned off or otherwise inactivated, the remaining LC which has not been transported into target cells can simply be removed from the body by standard biologic processes for expelling foreign materials, e.g. coughing, immune system or lymphatic system transport and the like.
(28) In addition, therapeutic use of only the LC of the neurotoxin BoNT may reduce the likelihood of the body developing an immunogenic response to the therapy that is seen with delivery of the intact toxin. This could be a major advantage in light of the repetitive application or injection of the toxin that is required to maintain a therapeutic effect.
(29) Non-Toxic Membrane Transport Mechanisms
(30) To date, the main application of purified or isolated light chain has been the study of its mechanism of action. To further this research, literature has reported the use of certain detergent based permeabilization techniques to deliver fragment BoNT (Bittner M A, DasGupta B R, Holz R W. Isolated light chains of botulinum neurotoxins inhibit exocytosis. Studies in digitonin-permeabilized chromaffin cells. J Biol Chem 1989 Jun. 25; 264 (18):10354-10360.) Further reference to the mechanism of permeability of cell membranes to deliver botulinum toxin are mentioned in U.S. Pat. No. 6,063,768 to First, and U.S. Pat. No. 6,632,440 to Quinn, Chaddock, et al “Expression and Purification of Catalytically Active Non-Toxic Endopeptidase Derivatives of Clostridium botulinum toxin type A”, Protein Expression and Purification, 25 (2002) 219-228, contemplating the insertion of the light chain of BoNT into a target cell without the heavy chain for purposes of deriving vaccines or in bench top studies of cell mechanisms of action. The contents of these references are expressly incorporated by reference in their entirety. None of the teachings contemplate a delivery of a fragment of neurotoxin using a clinically acceptable permeabilization technique in vivo for therapeutic uses as is contemplated by the present invention.
(31) For purposes of this specification, the term “poration” includes various forms of electroporation, such as the use of pulsed electric fields (PEFs), nanosecond pulsed electric fields (nsPEFs), ionophoreseis, electrophoresis, electropermeabilization, as well as other energy mediated permeabilization, including sonoporation (mediated by ultrasonic or other acoustic energy), and/or combinations thereof, to create temporary pores in a targeted cell membrane. Similarly, the term “electrode” or “energy source” used herein, encompasses the use of various types of energy producing devices, including x-ray, radiofrequency (RF), DC current, AC current, microwave, ultrasound, adapted and applied in ranges to produce membrane permeabilization in the targeted cell.
(32) Reversible electroporation, first observed in the early 1970's, has been used extensively in medicine and biology to transfer chemicals, drugs, genes and other molecules into targeted cells for a variety of purposes such as electrochemotherapy, gene transfer, transdermal drug delivery, vaccines, and the like.
(33) In general, electroporation may be achieved utilizing a device adapted to activate an electrode set or series of electrodes to produce an electric field. Such a field can be generated in a bipolar or monopolar electrode configuration. When applied to cells, depending on the duration and strength of the applied pulses, this field operates to increase the permeabilization of the cell membrane and reversibly open the cell membrane for a short period of time by causing pores to form in the cell lipid bilayer allowing entry of various therapeutic elements or molecules, after which, when energy application ceases, the pores spontaneously close without killing the cell after a certain time delay. As characterized by Weaver, Electroporation: A General Phenomenon for Manipulating Cells and Tissues Journal of Cellular Biochemistry, 51:426-435 (1993), short (1-100 .mu.s) and longer (1-10 ms) pulses have induced electroporation in a variety of cell types. In a single cell model, most cells will exhibit electroporation in the range of 1-1.5V applied across the cell (membrane potential).
(34) In addition, it is known in the art that macromolecules can be made to cross reversibly created pores at voltages of 120V or less applied to cells for durations of 20 microseconds to many milliseconds. For applications of electroporation to cell volumes, ranges of 10 V/cm to 10,000 V/cm and pulse durations ranging from 1 nanosecond to 0.1 seconds can be applied. In one example, a relatively narrow (pee) high voltage (200V) pulse can be followed by a longer (>msec) lower voltage pulse (<100V). The first pulse or series of pulses open the pores and the second pulse or series of pulses assist in the movement of the BoNT-LC across the cell membrane and into the cell.
(35) Certain factors affect how a delivered electric field will affect a targeted cell, including cell size, cell shape, cell orientation with respect to the applied electric field, cell temperature, distance between cells (cell-cell separation), cell type, tissue heterogeneity, properties of the cellular membrane and the like.
(36) Various waveforms or shapes of pulses may be applied to achieve electroporation, including sinusoidal AC pulses, DC pulses, square wave pulses, exponentially decaying waveforms or other pulse shapes such as combined AC/DC pulses, or DC shifted RF signals such as those described by Chang in Cell Potation and Cell Fusion using and Oscillating Electric Field, Biophysical Journal October 1989, Volume 56 pgs 641-652, depending on the pulse generator used or the effect desired. The parameters of applied energy may be varied, including all or some of the following: waveform shape, amplitude, pulse duration, interval between pulses, number of pulses, combination of waveforms and the like.
(37) A schematic example of the methods of the present invention are shown in
(38) Of particular interest for application in certain therapeutic target conditions is the developing field of sonoporation. Just as pulses of high voltage electricity can open transient pores in the cell membrane, ultrasonic energy can do the same. See for example Guzman et al. “Equilibrium Loading of Cells with Macromolecules by Ultrasound: Effects of Molecular Sizing and Acoustic Energy,” Journal of Pharmaceutical Sciences, 91:7, 1693-1701, which examines the viability of ultrasound to deliver molecules of a variety of sizes into target cells. In addition, techniques for nebulizing fluids and aqueous drugs are well known in the art, and as such, devices of the present invention may be adapted to introduce a BoNT-LC solution to a target region, such as the lung and then effect selective membrane transport of the BoNT-LC into the cell using sonoporation.
(39) For example, U.S. Pat. No. 6,601,581 to Babaev, hereby incorporated by reference in its entirety, describes certain techniques for delivering therapeutic agents using ultrasound for pulmonary delivery via an aerosolizing technique. Further, Guzman, et al, depicts delivery of molecules from a low of 62 Da up to 464 kDa (a range of 0.6-18.5 nm radius). Since the LC of the botulinum toxin is in the 50 kDa range, the LC would be very susceptible to sonoporetic delivery. Furthermore, Guzman, et al also showed that for all size ranges tested, levels of macromolecule within the cell reached thermodynamic equilibrium with the extracellular environment, and the cell uptake also depended on the energy delivered, as expressed in J/cm2. As such, the sonoporetic delivery of LC to the targeted regions may be controlled by adjusting the concentration of the LC exposed to the target region (e.g. wall or membrane of the lung), the energy delivered to the target region, or both.
Catheter Devices
(40) To achieve the goals of the present invention, it may be desirable to employ methods and apparatus for achieving cell membrane permeabilization via the application of an energy source, either from a catheter located directly in the vicinity of the targeted cells, or an externally focused energy system. For purposes of this specification, the term “catheter” may be used to refer to an elongate element, hollow or solid, flexible or rigid and capable of percutaneous introduction to a body (either by itself, or through a separately created incision or puncture), such as a sheath, a trocar, a needle, a lead. Further descriptions of certain electroporation catheters are described in U.S. Patent Application 60/701,747, filed on Jul. 22, 2005, the full disclosure of which is expressly incorporated herein by reference.
(41)
(42) Referring to
(43) Further catheter device and electrode configurations are shown in
(44)
(45)
(46)
(47)
(48)
(49) Since air is a very effective insulator against transmission of ultrasonic energy, the treatment area in the lung may be more precisely controlled by the concentration of the LC mist and the intensity of the ultrasonic energy. A fairly steep drop off in energy delivery would occur as mist concentration diffused, effectively protecting areas outside the predetermined radius surrounding the distal end of the delivery device. According to the present invention, since no functional neurotoxin exists without an effective membrane transport technology, terminating the energy application leaves a harmless mist that is then coughed up (if resident in the lungs) or otherwise metabolized and excreted by the body.
(50) Any of the catheter devices described herein, or described in the contemporaneously filed U.S. Patent Application 60/701,747, previously incorporated by reference in its entirety, may be adapted to include an energy delivery element such as those described herein for purposes of providing a membrane transport system for delivery of a fragment of neurotoxin. In addition, certain catheter devices and methods such as those set forth in U.S. Pat. Nos. 5,964,223 and 6,526,976 to Baran may be adapted to include energy transmission elements capable of producing a porative effect at the cellular level, including electrodes, ultrasonic elements and the like, for treatment in the respiratory tract.
(51) Furthermore, any of the foregoing systems may include electrodes or other monitoring systems either located on the treatment catheter, or external to the patient, to determine the degree of treatment to the region, including, thermocouple, ultrasound transducers, fiberoptics, sensing or stimulating electrodes. Further, it may be desirable to incorporate multiple pairs of electrodes that may be activated in pairs, in groups, or in a sequential manner in order to maximize the desired shape of the energy field (EF) while minimizing the field strength requirements.
(52) Implantable Devices
(53) Just as energy may be delivered to a targeted region to facilitate the delivery of fragmented neurotoxin via a catheter system, it is also within the scope of the present invention to deliver neurotoxins via an implantable system, including a pulse generator, lead and drug pump as depicted in
(54) Examples of useful implantable devices of the present invention arc, devices such as those set forth in U.S. Pat. No. 5,820,589 to Torgerson et al, the entire contents of which are hereby incorporated by reference, the SynchroMed® programmable pump available from Medtronic, Inc. (Minneapolis, Minn.), and the neurostimulation units such as the RESTORE* or SynergyPlus® available from Medtronic, Inc., modified if necessary to deliver the desired voltage range for cell membrane permeabilization. Implantation of the neurostimulation device is further described in U.S. Pat. No. 6,847,849, incorporated herein by reference in its entirety.
(55) The non-toxic nature of the BoNT in the absence of applied energy makes it possible to contemplate placing a bolus of neurotoxin in the body of a patient in what might otherwise be a toxic amount. This is particularly advantageous, since the traditional treatment regime using neurotoxins, is typically repeat injections of the toxins every 3 to 6 months and sometimes more frequently depending on the application. Certainly in more chronic conditions such as chronic pain, tremor, spasm, palsy and the like, such a fully implantable system may be highly desirable.
Non-Invasive Devices
(56) It is within the scope of the invention to deliver either the energy or the therapeutic BoNT-LC non-invasively, or both. For example,
(57) A combination of these non-invasive approaches may also be advantageous as shown in
(58) In a further aspect of the present invention, the fragmented molecule BoNT-LC may be delivered intravenously to a patient to achieve a systemic affect. A non-invasive energy application device, such as those described above, may then be targeted at the area of interest to porate the target area, thereby locally delivering the BoNT-LC to the region sufficiently porated by the applied energy.
(59) Cosmetic and Myofacial Applications. For some conditions, it may be desirable to apply the energy field from the surface of the skin to produce a porative effect, while injecting the BoNT-LC fragment into the targeted facial muscles as shown in
Intraluminal Devices
(60) It may further be advantageous to position catheters of the present invention through vessels in the body to direct them to various regions to affect neurotransmitters in the cardiovascular system. Intraluminal catheters such as those shown in United States Patent Applications 2001/0044596 to Jaafar and 2002/0198512 to Seward, hereby incorporated by reference in their entirety, may be used in this application of the present invention.
Treatment Enhancements
(61) In some applications of the present invention, it may be desirable to assess the appropriate location for the therapy prior to treatment, the therapeutic effect as it is delivered, and ultimately the resulting effect. To achieve this, once the treatment device is in place adjacent the tissue to be treated, the energy generator may be activated, causing an energized field to be generated in the target area. Prior to activation of therapeutic voltages and agent, stimulation using one or more electrodes may be used to elicit a nerve response or reflex. By observing the nerve response, a target treatment location can be confirmed. Similarly, once the therapy has been delivered, a similar stimulation response may be sought, to determine presence or lack of neurogenic response.
(62) In operation, effects of electroporation and delivery of a therapeutic dose of BoNT LC may be selective due to the cellular structure and orientation of the targeted cells. For example, targeted cells may be preferentially affected due to size, avoiding smaller or cross-oriented tissue cells.
(63) In a further aspect of the present invention, the method of delivering the LC fragment of the BoNT molecule may include the use of a media that contains microspheres or microbubbles, such as Optison™ sold by GE Healthcare (www.amershamhealth-us.com/optison/). Delivery of an ultrasound energy (or other form of energy, for example, laser, RF, thermal, energy) to the media causes the microspheres to rupture, which causes a release of energy toward the targeted region. Such a technique may assist in the desired porative effect by reducing the amount of applied energy required to create poration in the targeted cell membrane. Bioeffects Caused by Changes in Acoustic Cavitation Bubble Density and Cell Concentration: A Unified Explanation Based on Cell-to-Bubble Ratio and Blast Radius, Guzman, et al. Ultrasound in Med. & Biol., Vol. 29, No. 8, pp. 1211-1222 (2003). In an alternative embodiment, the LC fragment may actually be contained or encapsulated within a microsphere to assist in delivery. Such enhancing elements may be delivered prior to energy application or during energy application.
(64) In a further aspect of the present invention, it may be advantageous to heat the targeted cells or surrounding tissue by either applying thermal energy directly to the region, or directing a heated fluid, such as saline to the region through an injection element, to aid the cell poration process. Other substances may also be injected to aid in the transmission of the BoNT-LC into the intracellular membrane, such as amino acids, detergents or other agents that may facilitate the catalytic activity of the LC, in addition to the applied energy.
(65) Referring now to
(66) Referring now
(67) Although various illustrative embodiments of the present invention are described above, it will be evident to one skilled in the art that various changes and modifications may be made without departing from the scope of the invention. It will also be apparent that various changes and modifications may be made herein without departing from the invention. The appended claims are intended to cover all such changes and modifications that fall within the true spirit and scope of the invention.