Therapeutic dosing of a neuregulin or a subsequence thereof for treatment or prophylaxis of heart failure
11235031 · 2022-02-01
Assignee
Inventors
- Anthony O. Caggiano (Larchmont, NY)
- Anindita Ganguly (White Plains, NY, US)
- Jennifer Iaci (Boonton, NY)
- Tom Parry (Hellertown, PA, US)
Cpc classification
A61P9/04
HUMAN NECESSITIES
A61K38/1883
HUMAN NECESSITIES
International classification
Abstract
The invention relates to treatment of heart failure in a mammal. Accordingly, the invention is directed to establishing a dosing regimen whereby the therapeutic benefits conferred by administration of a neuregulin such as glial growth factor 2 (GGF2) or a subsequence thereof are maintained and/or enhanced, while concomitantly minimizing any potential side effects.
Claims
1. A method for treating heart failure in a mammal, said method comprising: providing a peptide comprising an epidermal growth factor-like (EGF-like) domain of glial growth factor 2 (GGF2); administering a therapeutically effective amount of said peptide to said mammal at an interval of not less than 96 hours, wherein said therapeutically effective amount is effective to treat heart failure in said mammal.
2. The method of claim 1, wherein said administering is performed every 96 hours.
3. The method of claim 1, wherein said administration is performed on a regimen selected from the group consisting of every: four days, week, 10 days, 14 days, month, two months, three months or four months.
4. The method of claim 1, wherein said mammal is a human.
5. The method of claim 1, wherein the peptide is: TABLE-US-00017 (SEQ ID NO: 22) SHLVKCAEKEKTFCVNGGECFMVKDLSNPSRYLCKCPNEFTGDRCQNYV MASFYKAEELYQ.
6. The method of claim 1, wherein the peptide is: TABLE-US-00018 (SEQ ID NO: 21) SHLVKCAEKEKTFCVNGGECFMVKDLSNPSRYLCKCPNEFTGDRCQNYVM ASFYKAEELY.
7. The method of claim 1, wherein said peptide is encoded by the neuregulin (NRG)-1 gene, the neuregulin (NRG)-2 gene, the neuregulin (NRG)-3 gene, or the neuregulin (NRG)-4 gene.
8. The method of claim 1, wherein the peptide comprises TABLE-US-00019 (SEQ ID NO: 4) SHLVKCAEKEKTFCVNGGECFMVKDLSNPSRYLCKCPNEFTGDRCQNYVMA SFYSTSTPFLSLPE.
9. The method of claim 1, wherein the administrating is by intravenous injection or subcutaneous injection.
10. The method of claim 1, wherein the interval is every 96 hours.
11. The method of claim 1, wherein the therapeutically effective amount is from about 1 mg/kg to about 10 mg/kg of the peptide.
12. The method of claim 1, wherein the therapeutically effective amount is from about 0.01 mg/kg to about 1 mg/kg of the peptide.
13. The method of claim 1, wherein the therapeutically effective amount is from about 0.1 mg/kg to about 1 mg/kg of the peptide.
14. The method of claim 1, wherein the therapeutically effective amount is about 3.25 mg/kg of the peptide.
15. The method of claim 1, wherein the therapeutically effective amount is about 0.625 mg/kg of the peptide.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF THE INVENTION
(18) The present inventors made the surprising discovery that discontinuous or intermittent administration of a neuregulin at appropriately spaced time intervals delivers a therapeutically effective amount of the neuregulin to a patient in need thereof and such a treatment regimen is useful for preventing, prophylaxing, ameliorating, minimizing, treating or reversing heart disease, such as congestive heart failure.
(19) Despite conventional wisdom and development practice pertaining to designing dosing regimens to maintain the most narrow range steady state concentrations, the present inventors demonstrate herein that dosing regimens for neuregulin administration that do not maintain narrow steady-state concentrations are equally as effective as more frequent dosing regimens. Indeed, the present inventors have shown that neuregulin treatment of heart failure with dosing intervals of at least 48 hours, 72 hours, 96 hours, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, 8 days, 9 days, 10 days, 11 days, 12 days, 13 days, 14 days 1 week, 2 weeks, 4 weeks, 1 month, 2 months, 3 months, 4 months, or any combination or increment thereof so long as the interval/regimen is at least 48 hours is as effective as daily dosing.
(20) In order to evaluate the pharmacokinetics of exogenous NRG, the present inventors have shown that the half-life of neuregulin when delivered intravenously is 4 to 8 hours and when delivered subcutaneously is 11-15 hours. See, e.g., Tables 1 and 2 and
(21) In keeping with conventional wisdom and development practice, other medical treatments for CHF are typically administered on at least a daily basis. The periodicity of such a regimen is thought to be required because CHF is a chronic condition, commonly caused by impaired contraction and/or relaxation of the heart, rather than an acute condition. In persons with a weak heart leading to impaired relaxation and CHF, medical treatments include drugs that block formation or action of specific neurohormones (e.g. angiotensin converting enzyme inhibitors (ACE-inhibitors), angiotensin receptor antagonists (ARBs), aldosterone antagonists and beta-adrenergic receptor blockers). These and other medications are now standard of care in chronic CHF as they have been demonstrated to result in improved symptoms, life expectancy and/or a reduction in hospitalizations. In the setting of acute exacerbation or chronic symptoms, patients are often treated with inotropes (e.g. dobutamine, digoxin) to enhance cardiac contractility, along with vasodilators (e.g, nitrates, nesiritide) and/or diuretics (e.g. furosemide) to reduce congestion. Patients with hypertension and congestive heart failure are treated with one or more antihypertensive agent such as beta-blockers, ACE-inhibitors and ARBs, nitrates (isosorbide dinitrate), hydralazine, and calcium channel blockers.
(22) Thus, despite typical practice with respect to treatment of CHF, the present inventors have demonstrated that a novel dosing regimen results in effective treatment of CHF, while avoiding undesirable side-effects. Although not wishing to be bound by theory, it is likely that such neuregulin treatment strengthens the pumping ability of the heart by stimulating, cardiomyocyte hypertrophy, and partially or completely inhibits further deterioration of the heart by suppressing cardiomyocyte apoptosis.
(23) By, way of additional background, the basic principle of dosing is to determine an effective circulating concentration and design a dosing regimen to maintain those levels. Pharmacokinetic (PK) and pharmacodynamic (PD) studies are combined to predict a dosing regimen that will maintain a steady-state level of a particular drug. The typical plan is to minimize the difference between the Cmax and Cmin and thereby reduce side-effects.
(24) Drugs are described by their ‘therapeutic index’ which is a ratio of the toxic dose or circulating levels divided by the effective dose or circulating concentrations. When the therapeutic index is large there is a wide safety range where an effective dose can be given without approaching toxic levels. When untoward effects result at concentrations too close to the effective concentrations the therapeutic index is described as narrow and the drug is difficult to administer safely.
(25) While developing dosing regimens one combines the PK/PD data with knowledge of the therapeutic index to design a dose and frequency of administration such that the compound is maintained at a concentration in a patient (e.g., a human) such that it is above the effective concentration and below the toxic concentration. If an effective concentration of the drug cannot be maintained without inducing unsafe effects, the drug will fail during development. Additional commentary pertaining to drug development can be found in a variety of references, including: Pharmacokinetics in Drug Development: Clinical Study Design and Analysis (2004, Peter Bonate and Danny Howard, eds.), which is incorporated herein in its entirety.
(26) Neuregulins are growth factors related to epidermal growth factors that bind to erbB receptors. They have been shown to improve cardiac function in multiple models of heart failure, cardiotoxicity and ischemia. They have also been shown to protect the nervous system in models of stroke, spinal cord injury, nerve agent exposure, peripheral nerve damage and chemotoxicity.
(27) Maintaining supranormal levels of exogenously supplied neuregulins has, however, been shown to have untoward effects including nerve sheath hyperplasia, mammary hyperplasia and renal nephropathy. These effects were observed following daily subcutaneous administration of neuregulin. See, e.g., Table 10.
(28) As set forth herein, subcutaneous administration was explored due to the prolonged half-life compared with intravenous administration and the initial belief that maintaining constant levels of ligand would be advantageous. Developing dosing regimens to reduce these effects would significantly enhance the ability of neuregulins to be utilized as therapeutics and it is toward this end that the present invention is directed. Demonstrating that less frequent dosing that does not maintain constant levels is also effective enables this development.
(29) Neuregulins: As indicated above, peptides encoded by the NRG-1, NRG-2, NRG-3 and NRG-4 genes possess EGF-like domains that allow them to bind to and activate ErbB receptors. Holmes et al. (Science 256:1205-1210, 1992) have shown that the EGF-like domain alone is sufficient to bind and activate the p185erbB2 receptor. Accordingly, any peptide product encoded by the NRG-1, NRG-2, or NRG-3 gene, or any neuregulin-like peptide, e.g., a peptide having an EGF-like domain encoded by a neuregulin gene or cDNA (e.g., an EGF-like domain containing the NRG-1 peptide subdomains C-C/D or C-C/D′, as described in U.S. Pat. Nos. 5,530,109, 5,716,930, and 7,037,888; or an EGF-like domain as disclosed in WO 97/09425) may be used in the methods of the invention to prevent or treat congestive heart failure. The contents of each of U.S. Pat. Nos. 5,530,109; 5,716,930; 7,037,888; and WO 97/0942.5 is incorporated herein in its entirety.
(30) Risk Factors: Risk factors that increase the likelihood of an individual's developing congestive heart failure are well known. These include, and are not limited to, smoking, obesity, high blood pressure, ischemic heart disease, vascular disease, coronary bypass surgery, myocardial infarction, left ventricular systolic dysfunction, exposure to cardiotoxic compounds (alcohol, drugs such as cocaine, and anthracycline antibiotics such as doxorubicin, and daunorubicin), viral infection, pericarditis, myocarditis, gingivitis, thyroid disease, radiation exposure, genetic, defects known to increase the risk of heart failure (such as those described in Bachinski and Roberts, Cardiol. Clin. 16:603-610, 1998; Siu et al., Circulation 8:1022-1026, 1999; and Arbustini et al., Heart 80:548-558, 1998), starvation, eating disorders such as anorexia and bulimia, family history of heart failure, and myocardial hypertrophy.
(31) In accordance with the present invention, neuregulins may be administered intermittently to achieve prophylaxis such as by preventing or decreasing the rate of congestive heart disease progression in those identified as being at risk. For example, neuregulin administration to a patient in early compensatory hypertrophy permits maintenance of the hypertrophic state and prevents the progression to heart failure. In addition, those identified to be at risk may be given cardioprotective neuregulin treatment prior to the development of compensatory hypertrophy.
(32) Neuregulin administration to cancer patients prior to and during anthracycline chemotherapy or anthracycline/anti-ErbB2 (anti-HER2) antibody (e.g., HERCEPTIN®) combination therapy can prevent a patient's cardiomyocytes from undergoing apoptosis, thereby preserving cardiac function. Patients who have already suffered cardiomyocyte loss also derive benefit from neuregulin treatment, because the remaining myocardial tissue responds to neuregulin exposure by displaying hypertrophic growth and increased contractility.
(33) Therapy: Neuregulins and peptides containing EGF-like domains encoded by neuregulin genes may be administered to patients or experimental animals with a pharmaceutically-acceptable diluent, carrier, or excipient. Compositions of the invention can be provided in unit dosage form.
(34) Conventional pharmaceutical practice is employed to provide suitable formulations or compositions, and to administer such compositions to patients or experimental animals. Although intravenous administration is preferred, any appropriate route of administration may be employed, for example, parenteral, subcutaneous, intramuscular, transdermal, intracardiac, intraperitoneal, intranasal, aerosol, oral, or topical (e.g., by applying an adhesive patch carrying a formulation capable of crossing the dermis and entering the bloodstream) administration.
(35) Therapeutic formulations may be in the form of liquid solutions or suspensions; for oral administration, formulations may be in the form of tablets or capsules; and for intranasal formulations, in the form of powders, nasal drops, or aerosols.
(36) Methods well known in the art for making formulations are found in, for example, “Remington's Pharmaceutical Sciences.” Formulations for parenteral administration may, for example, contain excipients, sterile water, or saline, polyalkylene glycols such as polyethylene glycol, oils of vegetable origin, or hydrogenated napthalenes. Other potentially useful parenteral delivery systems for administering molecules of the invention include ethylene vinyl acetate copolymer particles, osmotic pumps, implantable infusion systems, and liposomes. Formulations for inhalation may contain excipients, for example, lactose, or may be aqueous solutions containing, for example, polyoxyethylene-9-lauryl ether, glycocholate and deoxycholate, or may be oily 25 solutions for administration in the form of nasal drops, or as a gel.
(37) As a further aspect of the invention there is provided the present compounds for use as a pharmaceutical especially in the treatment or prevention of the aforementioned conditions and diseases. Also provided herein is the use of the present compounds in the manufacture of a medicament for the treatment or prevention of one of the aforementioned conditions and diseases.
(38) With respect to intravenous injections, dose levels range from about 0.001 mg/kg, 0.01 mg/kg to at least 10 mg/kg, in regular time intervals of from at least about every 24, 36, 48 hours to about every 96 hours and especially every 48, 72, or 96 hours or more as set forth herein. In a particular embodiment, intravenous injection dose levels range from about 0.1 mg/kg to about 10 mg/kg, in regular time intervals of from about every 48 hours to about every 96 hours and especially every 48, 72, or 96 hours or more as set forth herein. In another particular embodiment, intravenous injection dose levels range from about 1 mg/kg to about 10 mg/kg, in regular time intervals of from about every 48 hours to about every 96 hours and especially every 48, 72, or 96 hours or more as set forth herein. In yet another particular embodiment, intravenous injection dose levels range from about 0.01 mg/kg to about 1 mg/kg, in regular time intervals of from about every 48 hours to about every 96 hours and especially every 48, 72, or 96 hour or more as set forth hereins. In yet another particular embodiment, intravenous injection dose levels range from about 0.1 mg/ka to about 1 mg/kg, in regular time intervals of from about every 48 hours to about every 96 hours and especially every 48, 72, or 96 hours or more as set forth herein.
(39) With respect to subcutaneous injections, dose levels range from about 0.01 mg/kg to at least 10 mg/kg, in regular time intervals of from about every 48 hours to about every 96 hours and especially every 48, 72, or 96 hours or more as set forth herein. In a particular embodiment, injection dose levels range from about 0.1 mg/kg to about 10 mg/kg, in regular time intervals of from about every 48 hours to about every 96 hours or more as set forth herein, and especially every 48, 72, or 96 hours. In another particular embodiment, injection dose levels range from about 1 mg/kg to about 10 mg/kg, in regular time intervals of from about every 48 hours to about every 96 hours or more as set forth herein, and especially every 48, 72, or 96 hours. In yet another particular embodiment, injection dose levels range from about 0.01 mg/kg to about 1 mg/kg, in regular time intervals of from about every 48 hours to about every 96 hours or more as set forth herein, and especially every 48, 72, or 96 hours. In yet another particular embodiment, injection dose levels range from about 0.1 mg/kg to about 1 mg/kg, in regular time intervals of from about every 48 hours to about every 96 hours or more as set forth herein, and especially every 48, 72, or 96 hours.
(40) Transdermal doses are generally selected to provide similar or lower blood levels than are achieved using injection doses.
(41) The compounds of the invention can be administered as the sole active agent or they can be administered in combination with other agents, including other compounds that demonstrate the same or a similar therapeutic activity and that are determined to be safe and efficacious for such combined administration. Other such compounds used for the treatment of CHF include brain natriuretic peptide (BNP), drugs that block formation or action of specific neurohormones (e.g. angiotensin converting enzyme inhibitors (ACE-inhibitors), angiotensin receptor antagonists (ARBs), aldosterone antagonists and beta-adrenergic receptor blockers), inotropes (e.g. dobutamine, digoxin) to enhance cardiac contractility, vasodilators (e.g., nitrates, nesiritide) and/or diuretics (e.g, furosemide) to reduce congestion, and one or more antihypertensive agents such as beta-blockers, ACE-inhibitors and ARBs nitrates (isosorbide dinitrate), hydralazine, and calcium channel blockers.
(42) As indicated above, medical intervention involving drug treatment calls for the selection of an appropriate drug and its delivery at an adequate dosage regimen. An adequate dosage regimen involves a sufficient dose, route, frequency, and duration of treatment. The ultimate objective of drug therapy is the acquisition of optimal drug concentrations at the site of action so as to enable the treated patient to overcome the pathologic process for which treatment is necessitated. Broadly speaking, basic knowledge of the principles of drug disposition facilitates the selection of appropriate dosage regimens. Therapeutic drug monitoring (TDM) can, however, be used in this context as a supplemental tool to assist an attending physician in determining effective and safe dosage regimens of selected drugs for medical therapy of individual patients.
(43) Target Concentration and Therapeutic Window: The definition of optimal drug concentration varies depending on the pharmacodynamic features of the particular drug. Optimal therapy for time-dependent antibiotics like penicillin, for example, is related to achieving peak concentration to MIC (minimum inhibitory concentration) ratios of 2-4 and a time above the MIC equal to 75% of the dose interval. For concentration-dependent antibiotics like gentamicin, for example, efficacy is related to obtaining peak concentration to MIC ratios of about 8-10. Irrespective of the nuances associated with administration of a particular drug, drug therapy aims to achieve target plasma concentrations (which often reflect the concentrations, at the site of action) within the limits of a “therapeutic window”, which has been previously determined based on the pharmacokinetic, pharmacodynamic and toxicity profiles of the drug in the target species. The width of this window varies for different drugs and species. When the difference between the minimum efficacious concentration and the minimum toxic concentration is small (2 to 4-fold), the therapeutic window is referred to as narrow in contrast, when there is a large difference between the effective and toxic concentration, the drug is viewed as having a wide therapeutic is window. An example of a drug with a narrow therapeutic window is digoxin, in which the difference between the average effective and toxic concentrations is 2 or 3-fold. Amoxicillin, on the other hand, has a wide therapeutic range and overdosing of a patient is not generally associated with toxicity problems.
(44) Variability in Drug Responsiveness: Pronounced variability among healthy subjects of the same species with respect drug responsiveness is common. Moreover, disease states have the potential to affect organ systems and functions (e.g., kidney, liver, water content) that may in turn affect drug responsiveness. This, in turn, contributes to increased differentials in drug responsiveness in sick individuals to whom the drug is administered. Yet another relevant issue relates to administration of more than one drug at a time, which results in pharmacokinetic interactions that can lead to alterations in responsiveness to one or both drugs. In summary, physiological (e.g., age), pathological (e.g., disease effects), and pharmacological (e.g., drug interaction) factors call alter the disposition of drugs in animals. Increased variability among individuals ensuing therefrom may result in therapeutic failure or toxicity in drugs with a narrow therapeutic index.
(45) The patient population that would benefit from a treatment regimen of the present invention is quite diverse, e.g., patients with impaired kidney function are good candidates because continuous levels of protein therapeutics are often associated with renal glomerular deposits. The utility of a therapeutic regimen that does not maintain constant plasma levels as is described in this invention would therefore, be very beneficial for patients with compromised renal function in which any diminution of existing function could be deleterious. Similarly, brief and intermittent exposure to a therapeutic such as GGF2, as described herein, can be beneficial for patients with tumor types that are responsive to chronic and continuous stimulation with a growth factor. Other patients that may specifically benefit from intermittent therapy as described herein are patients with schwannomas and other peripheral neuropathies. It is an advantage of the present invention that intermittent dosing may have significant advantages in not maintaining continuous side-effect-related stimulation of various tissues.
(46) The proper timing of blood sampling for the purposes of determining serum drug level, as well as the interpretation of the reported level require consideration of the pharmacokinetic properties of the drug being measured. Some terms used in discussion of these properties are defined in the following paragraphs.
(47) Half-Life: The time required for the serum concentration present at the beginning of an interval to decrease by 50%. Knowing an approximate half-life is essential to the clinician since it determines the optimal dosing schedule with oral agents, the intradose fluctuation of the serum concentration, and the time required to achieve steady state.
(48) In brief, multiple pharmacokinetic studies have been performed for GGF2. Typical half-lives for GGF2 are between 4 and 8 hours for the intravenous (iv) route, whereas the half-life of subcutaneously (sc) administered GGF2 is between 11 and 15 hours. Cmax, AUG, Tmax and T1/2 are shown in Tables 1 and 2 below. Where the half-life was too long to be determined accurately by these methods a dash is presented in lieu of a time.
(49) TABLE-US-00001 Table 1 and Table 2 Mean Pharmacokinetics of 125I-rhGGF2-Derived Radioactivity in Plasma of Male Sprague-Dawley Rats Following a Single Intravenous or Subcutaneous Dose of 125I-rhGGF2 Appendix 7 Group 1 (n = 2) Group 2 (n = 1) Parameters Total TCAPrecip Total TCAPrecip Cmax (ug eq/g) 0.3289 0.2953 0.0157 0.01 AUC 0-t (ug eq-h/g) 1.27 0.01 0.27 0.17 AUC inf (ug eq-h/g) 1.37 0.96 0.39 0.26 Tmax (h) 0.08 0.08 6.0 6.0 Half-life 6.37 6.11 13.20 14.66 Group 1 - i.v. Group 2 - s.c. Appendix 9 Group 1 (n = 2) Group 2 (n = 1) Parameters Total TCAPrecip Total TCAPrecip Cmax (ug eq/g) 0.2611 0.2291 0.0197 0.0034 AUC 0-t (ug eq-h/g) 1.488 0.567 0.335 0.064 AUC inf (ug eq-h/g) 1.667 0.62 — — Tmax (h) 0.08 0.08 12.0 12.0 Half-life 7.75 7.96 — — Group 1 - i.v. Group 2 - s.c.
(50) The plasma concentrations after administration are shown in
(51) As is evident from the tables and figures it is not possible to maintain steady state therapeutic levels by either dosing route with every fourth day, every other day or every day of dosing. Levels are unmeasurable after a day and even long before that, as reflected by the data set forth in Table 11.
(52) TABLE-US-00002 TABLE 11 PK Parameters for GGF2 after Intravenous Administration* AUC.sub.0-∞/ AUC.sub.0-last/ Dose AUC.sub.0-∞ Dose ((hr .Math. ng/mL)/ AUC.sub.0-last Dose ((hr .Math. ng/mL)/ CL t.sub.1/2 Vss (mg/kg) (hr .Math. ng/mL) mg/kg) (hr .Math. ng/mL) mg/kg) (mL/min/kg) (h) (mL/kg) Rats 8 16100 ± 20500 2010 ± 2560 16800 ± 22300 2100 ± 2790 18.1 ± 12.7 1.46 ± 1.84 1050 ± 331 16 39600 ± 9440 2470 ± 590 38300 ± 10000 2390 ± 625 7.00 ± 1.33 1.69 ± 0.430 532 ± 145 Monkeys 8 15900 ± 1690 1980 ± 212 15100 ± 1730 1890 ± 217 8.48 ± 0.91 2.02 ± 0.358 1110 ± 113 *taken from data obtained from plasma GGF2 concentrations measured by ELISA. Data reported are mean ± SD.
(53) Steady State: Steady state serum concentrations are those values that recur with each dose and represent a state of equilibrium between the amount of drug administered and the amount being eliminated in a given time interval. During long term dosage with any drug, the two major determinants of its mean steady state serum concentration are the rate at which the drug is administered and the drug's total clearance in that particular patient.
(54) Peak Serum Concentration: The point of maximum concentration on the serum concentration-versus-time curve. The exact time of the peak serum concentration is difficult to predict since it represents complex relationships between input and output rates.
(55) Trough Serum Concentration: The minimum serum concentration found during a dosing interval. Trough concentrations are theoretically present in the period immediately preceding administration of the next dose.
(56) Absorption: The process by which a drug enters the body. Intravascularly administered drugs are absorbed totally, but extravascular administration yields varying degrees and rates of absorption. The relationship between the rate of absorption and the rate of elimination is the principle determinant of the drug concentration in the bloodstream.
(57) Distribution: The dispersion of the systemically available drug from the intravascular space into extravascular fluids and tissues and thus to the target receptor sites.
(58) Therapeutic Range: That range of serum drug concentrations associated with a high degree of efficacy and a low risk of dose-related toxicity. The therapeutic range is a statistical concept: it is the concentration range associated with therapeutic response in the majority of patients. As a consequence, some patients exhibit a therapeutic response at serum levels below the lower limit of the range, while others require serum levels exceeding the upper limit for therapeutic benefit.
(59) Correct timing of sample collection is important, since drug therapy is often revised on the basis of serum concentration determinations. The absorption and distribution phases should be complete and a steady-state concentration achieved before the sample is drawn. Levels obtained before a steady-state concentration exists may be erroneously low; increasing the dosage based on such a result could produce toxic concentrations. In addition, when making comparative measurements, it is important that the sampling time be consistent.
(60) The timing of blood samples in relation to dosage is critical for correct interpretation of the serum concentration result. The selection of the time that the sample is drawn in relation to drug administration should be based on the pharmacokinetic properties of the drug, its dosage form and the clinical reason for assaying the sample (e.g., assessment of efficacy or clarification of possible drug-induced toxicity). For routine serum level monitoring of drugs with short half-lives, both a steady state peak and trough sample may be collected to characterize the serum concentration profile; for drugs with a long half-life, steady-state trough samples alone are generally sufficient.
(61) By “congestive heart failure” is meant impaired cardiac function that renders the heart unable to maintain the normal blood output at rest or with exercise, or to maintain a normal cardiac output in the setting of normal cardiac tilling pressure. A left ventricular ejection fraction of about 40% or less is indicative of congestive heart failure (by way of comparison, an ejection fraction of about 60% percent is normal). Patients in congestive heart failure display well-known clinical 1.5 symptoms and signs, such as tachypnea, pleural effusions, fatigue at rest or with exercise, contractile dysfunction, and edema. Congestive heart failure is readily diagnosed by well known methods (see, e.g., “Consensus recommendations for the management of chronic heart failure,” Am. J. Card 83(2A): 1A-33-A,1999).
(62) Relative severity and disease progression are assessed using well known methods, such as physical examination, echocardiography, radionuclide imaging, invasive hemodynamic monitoring, magnetic resonance angiography, and exercise treadmill testing coupled with oxygen uptake studies.
(63) By “ischemic heart disease” is meant any disorder resulting from an imbalance between the myocardial need for oxygen and the adequacy of the oxygen supply. Most cases of ischemic heart disease result from narrowing of the coronary arteries, as occurs in atherosclerosis or other vascular disorders.
(64) By “myocardial infarction” is meant a process by which ischemic disease results in a region of the myocardium being replaced by scar tissue.
(65) By “cardiotoxic” is meant a compound that decreases heart function by directly or indirectly impairing or killing cardiomyocytes.
(66) By “hypertension” is meant blood pressure that is considered by a medical professional (e.g., physician or a nurse) to be higher than normal and to carry an increased risk for developing congestive heart failure.
(67) By “treating” is meant that administration of a neuregulin or neuregulin-like peptide slows or inhibits the progression of congestive heart failure during the treatment, relative to the disease progression that would occur in the absence of treatment, in a statistically significant manner. Well known indicia such as left ventricular ejection fraction, exercise performance, and other clinical tests as enumerated above, as well as survival rates and hospitalization rates may be used to assess disease progression. Whether or not a treatment slows or inhibits disease progression in a statistically significant manner may be determined by methods that are well known in the art (see, e.g., SOLVD Investigators, N. Engl. J. Med. 327:685-691, 1992 and Cohn et al., N. Engl. J Med. 339:1810-1816, 1998).
(68) By “preventing” is meant minimizing or partially or completely inhibiting the development of congestive heart failure in a mammal at risk for developing congestive heart failure (as defined in “Consensus recommendations for the management of chronic heart failure.” Am. J. Cardiol., 83 (2A): 1A-38-A, 999). Determination of whether congestive heart failure is minimized or prevented by administration of a neuregulin or neuregulin-like peptide is made by known methods, such as those described in SOLVD Investigators, supra, and Cohn et al., supra.
(69) The term “therapeutically effective amount” is intended to mean that amount of a drug or pharmaceutical agent that elicits the biological or medical response of a tissue, a system, animal or human that is being sought by a researcher, veterinarian, medical doctor or other clinician. A therapeutic change is a change in a measured biochemical characteristic in a direction expected to alleviate the disease or condition being addressed. More particularly, a “therapeutically effective amount” is an amount sufficient to decrease the symptoms associated with a medical condition or infirmity, to normalize body functions in disease or disorders that result in impairment of specific bodily functions, or to provide improvement in one or more of the clinically measured parameters of a disease.
(70) The term “prophylactically effective amount” is intended to mean that amount of a pharmaceutical drug that will prevent or reduce the risk of occurrence of the biological or medical event that is sought to be prevented in a tissue, a system, animal or human by a researcher, veterinarian, medical doctor or other clinician.
(71) The term “therapeutic window” is intended to mean the range of dose between the minimal amount to achieve any therapeutic change, and the maximum amount which results in a response that is the response immediately before toxicity to the patient.
(72) By “at risk for congestive heart failure” is meant an individual who smokes, is obese (i.e., 20% or more over their ideal weight), has been or will be exposed to a cardiotoxic compound (such as an anthracycline antibiotic), or has (or had) high blood pressure, ischemic heart disease, a myocardial infarct, a genetic defect known to increase the risk of heart failure, a family history of heart failure, myocardial hypertrophy, hypertrophic cardiomyopathy, left ventricular systolic dysfunction, coronary bypass surgery, vascular disease, atherosclerosis, alcoholism, periocarditis, a viral infection, gingivitis, or an eating disorder (e.g., anorexia nervosa or bulimia), or is an alcoholic or cocaine addict.
(73) By “decreasing progression of myocardial thinning” is meant maintaining hypertrophy of ventricular cardiomyocytes such that the thickness of the ventricular wall is maintained or increased.
(74) By “inhibits myocardial apoptosis” is meant that neuregulin treatment inhibits death of cardiomyocytes by at least 10%, more preferably by at least 15%, still more preferably by at least 25%, even more preferably by at least 50%, yet more preferably by at least 75%, and most preferably by at least 90%, compared to untreated cardiomyocytes.
(75) By “neuregulin” or “NRG” is meant a peptide that is encoded by an NRC-1, NRG-2, or NRG-3 gene or nucleic acid (e.g., a cDNA), and binds to and activates ErbB2, ErbB3, or ErbB4 receptors, or combinations thereof.
(76) By “neuregulin-1,” “NRG-1,” “heregulin,” “GGF2,” or “p185erbB2 ligand” is meant a peptide that binds to the ErbB2 receptor when paired with another receptor (ErbB1, ErbB3 or ErbB4) and is encoded by the p 185erbB2 ligand gene described in U.S. Pat. Nos. 5,530,109; 5,716,930; and 7,037,888, each of which is incorporated herein by reference in its entirety.
(77) By “neuregulin-like peptide” is meant a peptide that possesses an EGF-like domain encoded by a neuregulin gene, and binds to and activates ErbB2, ErbB3, ErbB4, or a combination thereof.
(78) By “epidermal growth factor-like domain” or “EGF-like domain” is meant a peptide motif encoded by the NRG-1NRG-2, or NRG-3 gene that binds to and activates ErbB2, ErbB3ErbB4, or combinations thereof, and bears a structural similarity to the EGF receptor-binding domain as disclosed in Holmes'et al., Science 256:1205-1210, 1992; U.S. Pat. Nos. 5,530,109; 5,716,930; 7,037,888; Hijazi et al., int. J. Oncol. 13:1061-1067, 1998; Chang et al., Nature 387509-512, 1997; Caraway et al., Nature 387:512-516, 1997; Higashiyama et al., J Biochem. 122:675-680, 1997; and WO 97/09425). See FIGS. 9-14 for nucleic and amino acid sequences corresponding to EGFL domains 1-6 encoded by the NRG-1 gene.
(79) By “anti-ErbB2 antibody” or “anti-HER2 antibody” is meant an antibody that specifically binds to the extracellular domain of the ErbB2 (also known as HER2 in humans) receptor and prevents the ErbB2 (HER2)-dependent signal transduction initiated by neuregulin binding.
(80) By “transformed cell” is meant a cell (or a descendent of a cell) into which a DNA molecule encoding a neuregulin or peptide having a neuregulin EGF-like domain has been introduced, by means of recombinant DNA techniques or known gene therapy techniques.
(81) By “promoter” is meant a minimal sequence sufficient to direct transcription. Also included in the invention are those promoter elements which are sufficient to render promoter-dependent gene expression controllable based on cell type or physiological status (e.g., hypoxic versus normoxic conditions), or inducible by external signals or agents; such elements may be located in the 5′ or 3′ or internal regions of the native gene.
(82) By “operably linked” is meant that a nucleic acid encoding a peptide (e.g., a cDNA) and one or more regulatory sequences are connected in such a way as to permit gene expression when the appropriate molecules (e.g., transcriptional activator proteins) are bound to the regulatory sequences.
(83) By “expression vector” is meant a genetically engineered plasmid or virus, derived from, for example, a bacteriophage, adenovirus, retrovirus; poxvirus, herpesvirus, or artificial chromosome, that is used to transfer a peptide (e.g., a neuregulin) coding sequence, operably linked to a promoter, into a host cell, such that the encoded peptide or peptide is expressed within the host cell.
(84) Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
(85) The discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention before the priority date of each claim of this application.
Other Embodiments
(86) While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure within known or customary practice within the art to which the invention pertains and may be applied to the essential features hereinbefore set forth, and follows in the scope of the appended claims.
(87) The following Examples will assist those skilled in the art to better understand the invention and its principles and advantages. It is intended that these Examples be illustrative of the invention and not limit the scope thereof.
EXAMPLES
(88) As indicated herein above, the neuregulins are a family of growth factors structurally related to Epidermal Growth Factor (EGF) and are essential for the normal development of the heart. Evidence suggests that neuregulins are a potential therapeutic for the treatment of heart disease including heart failure, myocardial infarction, chemotherapeutic toxicity and viral myocarditis.
(89) The studies described herein were served to define dosing in the left anterior descending (LAD) artery ligation model of congestive heart failure in the rat. Multiple neuregulin splice variants were cloned and produced. A neuregulin fragment of consisting of the EGF-like domain (EGF-Id) from previous reports (Liu et al., 2006) was compared to a full-length neuregulin known as glial growth factor 2 (GGF2) and the EGF-like domain with the Ig domain (EGF-Ig). Male and female Sprague-Dawley rats underwent LAD artery ligation. At 7 days post ligation rats were treated intravenously (iv) with neuregulin daily. Cardiac function was monitored by echocardiography.
(90) The first study compared 10 days of dosing with equimolar amounts of EGF-Id or GGF2 (for GGF2 this calculates to 0.0625 and 0.325 mg/kg). GGF2 treatment resulted in significantly (p<0.05) greater improvement in Ejection Fraction (EF) and Fractional Shortening (FS) than did EGF-Id at the end dosing period. The second study compared 20 days of GGF2 with EGF-Id and EGF-1g at equimolar concentrations. GGF2 treatment resulted in significantly improved EF, FS and LVESD (p<0.01). Improvements in cardiac physiology were not maintained for this period with either EGF-Id or EGF-Ig. The third study compared daily (q 24 hour), every other day (q 48 hour) and every fourth day (q 96 hour) dosing for 20 days with GGF2 (3.25 mg/kg). All three GGF2 treatment regimens resulted in significant improvements in cardiac physiology including EF, ESV and EDV and the effects were maintained for 10 days following termination of dosing. The studies presented here confirm GGF2 as the lead neuregulin compound and establish optimal dosing regimens for administering same.
(91) As shown herein, the present studies establish the relative efficacy of GGF2 compared with published neuregulin fragments (Liu et al., 2.006), initiate dose ranging and dose frequency studies, and determine if BSA excipient is required as previously reported.
(92) Methods and Materials
(93) Cloning, expression and purification of the IgEGF (Ig:154Y) domain of GGF2 (EGF-Ig) DNA: IgEGF domain was amplified from an existing GGF2 eDNA and cloned into pet 15b vector (Novagen cat #69661-3) using Ndel and BamHl restriction sites. The resulting protein is a 21.89 kda+˜3 kDa His tag (=˜25 kDa).
(94) DNA sequence of IgEgf pet 15 clone: The underlined sequences are the primers used for amplification. The bolded sequences are the cloning sites used to insert the sequence into the pet sector (Ndel and BamHl).
(95) TABLE-US-00003 CATATGttgcctccccaattgaaagagatgaaaagccaggaatcggctgcaggttccaaa L P P Q L K E M K S Q E S A A G S K ctagtccttcggtgtgaaaccagttctgaatactcctctctcagattcaagtggttcaag L V L R C E T S S E Y S S L R F K W F K aatgggaatgaattgaatcgaaaaaacaaaccacaaaatatcaagatacaaaaaaagcca N G N E L N R K N K P Q N I K I Q K K P gggaagtcagaacttcgcattaacaaagcatcactggctgattctggagagtatatgtgc G K S E L R I N K A S L A D S G E Y M C aaagtgatcagcaaattaggaaatgacagtgcctctgccaatatcaccatcgtggaatca K V I S K L G N D S A S A N I T I V E S aacgctacatctacatccaccactgggacaagccatcttgtaaaatgtgcggagaaggag N A T S T S T T G T S H L V K C A E K E aaaactttctgtgtgaatggaggggagtgcttcatggtgaaagacctttcaaacccctcg K T F C V N G G E C F M V K D L S N P S agatacttgtgcaaatacccaaatgagtttactggtgatcgctgccaaaactacgtaatg R Y L C K C P N E F T G D R C Q N Y V M gccagcttctacGGATCC (SEQ ID NO: 15) A S F Y (SEQ ID NO: 16)
(96) The final translated protein from pet15b vector is shown below. The vector portion is underlined,
(97) TABLE-US-00004 (SEQ ID NO: 17) M G G S H H H H H H G M A S M T G G T A N G V G D L Y D D D D K V P G S L P P Q L K E M K S Q E S A A G S K L V L R C E T S S E Y S S L R F K W F K N G N E L N R K N K P Q N I K I Q K K P G K S E L R I N K A S L A D S G E Y M C K V I S K L E N D S A S A N I T I V E S N A T S T S T T G T S H L V K C A E K E K T F C V N G G E C F M V K D L S N P S R Y L C K C P N E F T G D R C Q N Y V M A S F Y
(98) Protein expression: The clone was transformed into B121 cells for protein expression using the Overnight Express Autoinduction System (Novagen) in LB media at 25° C. for 24 hours.
(99) Protein Refolding: Adapted from Novagen Protein Refolding Kit, 70123-3.
(100) Protein Purification: His TRAP columns—as per manufacturer's instructions
(101) Western blotting: Protein expression was assessed by western blotting. Resulting band with the His tag runs at around 25 kD.
(102) A 4-20% criterion gel (Biorad) was used for protein resolution followed by transfer onto Protran nitrocellulose paper (0.1 μm pore size from Schliecher and Schull). The blot is blocked in 5% milk in TBS-T (0.1%). Primary antibody (Anti EGF Human NRG1-alpha/HRG1-alpha Affinity Purified Polyclonal Ab Cat #AF-296-NA from R&D systems) 1:1000 dilution in 5% milk in TBS-T-1 hour at RT (also works at 4° C. overnight). Rabbit anti goat HRP secondary antibody was used at 1:10,000 dilution in 5% milk in TBS-T for 1 hour at RT. All washes were per in TBS-T
(103) Purification Protocol for Ig154Y: The cultures are grown at 25° C. in Overnight Express Autoinduction System 1 from Novagen (cat #71300-4). The culture is spun down and the pellets are extracted, solubilized and re-folded to acquire the Ig154Y before purification can take place.
(104) Materials for extraction, solubilization and re-folding:
(105) 10× Wash Buffer: 200 mM Tris-HCl, pH 7.5, 100 mM EDTA, 10% Triton X-100
(106) 10× Solubilization Buffer: 500 mM CAPS, pH 11.0
(107) 50× Dialysis Buffer: Tris-HCl, pH 8.5
(108) 30% N-laurylsarcosine—add as powder (Sigma 61739-5G)
(109) 1M DTT
(110) Reduced glutathione (Novagen 3541)
(111) Oxidized glutathione (Novagen 3542)
(112) A. Cell Lysis and Preparation of Inclusion Bodies
(113) Cell pellets were thawed and re-suspended in 30 mls 1×wash buffer.
(114) Protease inhibitors (25 ul of 10× per 50 mls), DNase (200 ul of 1 mg/ml per 50 ml) and MgCl.sub.2 (500 ul of 1M per 50 mls) were added to suspension.
(115) Cells were lysed by sonication with cooling on ice.
(116) Following sonication inclusion bodies were collected by centrifugation at 10000×g for 12 minutes.
(117) Supernatant was removed and the pellet, thoroughly re-suspended in 30 mls of 1× Wash Buffer.
(118) Step 4 was repeated.
(119) The pellet was thoroughly re-suspended in 30 mls of 1× Wash Buffer.
(120) The inclusion bodies were collected by centrifugation at 10000×g for 10 minutes.
(121) B. Solubilization and Refolding
(122) From the wet weight of inclusion bodies to be processed, calculate the amount of 1× Solubilization Buffer necessary to re-suspend the inclusion bodies at a concentration of 10-15 mg/ml. If the calculated volume is greater than 250 ml, use 250 ml.
(123) At room temperature, prepare the calculated volume of 1× Solubilization Buffer supplemented with 0.3% N-laurylsaroosine (up to 2% may be used if needed in further optimization) (300 mg/100 ml, buffer) and 1 mM DTT.
(124) Add the calculated amount of 1× Solubilization Buffer from step 2 to the inclusion bodies and gently mix. Large debris can be broken up by repeated pipetting.
(125) Incubate in refrigerator shaker at 25° C., 54-100 rpm for 4-5 hours (or longer if needed in further optimization).
(126) Clarify by centrifugation at 10000×g for 10 minutes at room temperature
(127) Transfer the supernatant containing the soluble protein into a clean tube.
(128) C. Dialysis Protocol for Protein Refolding
(129) Prepare the required volume of buffer for dialysis of solubilized protein. The dialysis should be performed with at least 2 buffer changes of greater than 50 times the volume of the sample. Dilute the 50× Dialysis Buffer to 1× at the desired volume and supplement with 0.1 mM DTT.
(130) Dialyze for at least 4 hours at 4° C. Change the buffer and continue. Dialyze for an additional 4 or more hours.
(131) Prepare additional dialysis buffer as determined in step 1, but omit DTT.
(132) Continue the dialysis through two additional changes (minutes 4 hr each), with the dialysis buffer lacking DTT.
(133) D. Redox Refolding Buffer to Promote Disulfide Bond Formation
(134) Prepare a dialysis buffer containing 1 mM reduced glutathione (1.2 g/4 L) and 0.2 mM oxidized glutathione (0.48 g/4 L) in 1× Dialysis Buffer. The volume should be 25 times greater than the volume of the solubilized protein sample. Chill to 4° C.
(135) Dialyze the refolded protein from step 1 overnight at 4° C.
(136) Materials for Purification
(137) AU procedures are done at 4° C.,
(138) Chemicals;
(139) Trizma Hydrochloride (Sigma T5941-500 G)
(140) Sodium Chloride 5M Solution (Sigma. S6546-4 L)
(141) Sodium Hydroxide 10N (J T Baker 5674-02)
(142) Imidazole (J T Baker N811-06)
(143) A. Purification on the HISPrep FF 16/10 Column—20 mls (GE Healthcare)
(144) Buffer A: 20 mM Tris-HCL+500 mM NaCl pH 7.5
(145) Buffer B: Buffer A+500 mM imidazole pH 7.5
(146) Equilibration of column: Buffer A—5 CV, Buffer B—5 CV, Buffer A—10 CV
(147) Load 20 ml of sample per run on 20 ml column at 05 ml/min
(148) Wash column with 5 CV of buffer A
(149) Elute column with 5 CV of 280 mM Imidazole.
(150) Clean with 10 CV of 100% Buffer B.
(151) Equilibrate with 15 CV of Buffer A
(152) Analyze fractions with a SDS-page silver stain
(153) Pool fractions with Ig154Y
(154) B. His-Tag Removal
(155) Removal of the His-Tag is done with A Thrombin Cleavage Capture Kit from Novagen (Cat #69022-3). Based on previous testing, the best conditions are room temperature for 1 hours with Thrombin at 0.005 U of enzyme per μl for every 10 μg of Ig154Y protein. After four hours of incubation, add 16 μl of Streptavidin Agarose slurry per unit of Thrombin enzyme. Rock sample for 30 minutes at room temp. Recover the 1g154Y through spin-filtration or sterile filtering (depending on volume).
(156) Full cleavage is determined by EGF and Anti-His western blotting.
(157) C. Concentration of Ig154Y
(158) Adjust to desired concentration with Millipore Centriprep 3000 MWCO 15 ml concentrator
(159) (Ultracel YM-3, 4320)
(160) D. Storage in Final Buffer
(161) Store in 20 mM Tris+500 mM NaCl pH 7.5 and 1×PBS+02% BSA.
(162) Cloning, expression and purification of 156 Q (EGF-Id) [NRG1b2 EGF domain (156 Q)]DNA: NRG3 b2 egf domain was cloned from human brain cDNA and cloned into pet 15b vector (Novagen cat #69661-3) using Ndel and BamHl restriction sites. The resulting protein is a 6.92 kda 3˜kDa His tag (=9.35 kDa)
(163) DNA sequence of NRG1b2 egf pet 15 clone
(164) The underlined sequences are the cloning sites (Ndel and BamHl)
(165) TABLE-US-00005 (SEQ ID NO: 18) CATATGAGCCA TCTTGTAAAA TGTGCGGAGA AGGAGAAAAC TTTCTGTGTG AATGGAGGGG AGTGCTTCAT GGTGAAAGAC CTTTCAAACC CCTCGAGATA CTTGTGCAAG TGCCCAAATG AGTTTACTGG TGATCGCTGC CAAAACTACG TAATGGCCAG CTTCTAGAAG GCGGAGGAGC TGTACCAGTA AGGATCC
(166) The final translated protein from pet15b vector is shown below. The egf domain is highlighted in green.
(167) TABLE-US-00006 (SEQ ID NO: 19) 10 20 30 MGSSHHHHHH SSGLVPRGSH MSHLVKCAEK EKTFCVNGGE CFMVKDLSNP 60 70 80 SRYLCKCPNE FTGDRCQNYV MASFYKAEEL YQ
(168) Calculated pI/Mw: 7.69/9349.58
(169) Protein Expression
(170) The clone was transformed into B121 cells for protein expression using the Overnight Express Autoinduction System (Novagen) in LB media at 25° C. for 24 hours. Expression is primarily in insoluble inclusion bodies.
(171) Protein Refolding: Adapted from Novagen Protein Refolding Kit, 70123-3.
(172) Protein Purification: Protein is loaded onto an anion exchange column DEAE at 2.5 ml/min.
(173) The EGF-Id fragment remains in the flow through, whereas the contaminants bind and elute at a higher salt. The loading and washing buffer is 50 mM Tris pH7.9 and elution buffer is 50 mM Tris pH7.9 with 1M NaCl. The flow through is pooled and concentrated with Centriprep YM-3 from Millipore.
(174) Western blotting: Protein expression is assessed by western blotting. Resulting hand runs at around 10 kD.
(175) A 4-20% criterion gel (Biorad) was used for protein resolution followed by transfer onto Protran nitrocellulose paper (0.1 μm pore size from Schliecher and Schull). The blot is blocked in 5% milk in TBS-T (0.1%). Primary antibody (Anti EGF Human NRG1-alpha/HRG1-alpha Affinity Purified Polyclonal Ab Cat #AF-296-NA from R&D systems) 1:1000 dilution in 5% milk in TBS-T-1 hour at RT (also works at 4° C. overnight). Rabbit anti goat HRP secondary antibody was used at 1:10,000 dilution in 5% milk in TBS-T for 1 hour at RT. All washes were performed in TBS-T
(176) Purification Protocol for NRG-156Q
(177) The cultures are grown at 25° C. in Overnight Express Autoinduction System 1 from Novagen (cat #71300-4). There is very little soluble NRG-156Q (EGF-Id) present. The culture is spun down and the pellets are extracted, solubilized and re-folded to acquire the NRG-156Q before purification can take place.
(178) Materials for Extraction, Solubilization and Re-Folding:
(179) 10× Wash Buffer: 200 mM Tris-HCl, pH 7.5, 100 mM EDTA, 10% Triton X-100
(180) 10× Solubilization Buffer: 500 mM CAPS, pH 11.0
(181) 50× Dialysis Buffer: 1M Tris-HCl, pH 8.5
(182) 30% N-lauryisarcosine—add as powder (Sigma 61739-5G) 1M DTT
(183) Reduced glutathione (Novagen 3541)
(184) Oxidized glutathione (Novagen 3542)
(185) A. Cell Lysis and Preparation of Inclusion Bodies
(186) Thaw and re-suspend cell pellet in 30 mls 1× wash buffer. Mix as needed for full re-suspension.
(187) Add protease inhibitors (25 ul of 10× per 50 mls). DNase (200 ul of 1 mg/ml per 50 ml) and MgCl2 (500 ul of 1M per 50 mls) to suspension.
(188) Lyse the cells by sonication. a. Cool the cells on ice throughout this step. b. Using the square tip, sonicate for 30 seconds on level 6, 10 times until suspension becomes less viscous. Let suspension cool on ice for 60 seconds between each sonication. Keep volume no higher than 40 mls in 50 ml conical tube when sonicating.
(189) When complete, transfer each suspension to 250 ml angled neck centrifuge bottles for use with F-16/250 rotor.
(190) Collect the inclusion bodies by centrifugation at 10,000×g for 12 minutes.
(191) Remove the supernatant (save a sample for analysis of soluble protein) and thoroughly re-suspend the pellet in 30 mls of 1× Wash Buffer.
(192) Repeat centrifugation as in Step 4 and save the pellet thoroughly re-suspend the pellet in 30 mls of 1× Wash Buffer.
(193) Collect the inclusion bodies by centrifugation at 10,000×g for 10 minutes. Decant the supernatant and remove the last traces of liquid by tapping the inverted tube on a paper towel.
(194) B. Solubilization and Refolding
(195) From the wet weight of inclusion bodies to be processed, calculate the amount of 1× Solubilization Buffer necessary to re-suspend the inclusion bodies at a concentration of 0-15 mg/ml. If the calculated volume is greater than 250 ml, use 250 ml.
(196) At room temperature, prepare the calculated volume of 1× Solubilization Buffer supplemented with 0.3% N-laurylsarcosine (up to 2% may be used if needed in further optimization) is (300 mg/100 mL buffer) and 1 mM DTT.
(197) Add the calculated amount of 1× Solubilization Buffer from step 2 to the inclusion bodies and gently mix. Large debris can be broken up by repeated pipetting.
(198) Incubate in refrigerator shaker at 25° C., 50-100 rpm for 4-5 hours.
(199) Clarify by centrifugation at 10,000×g for 10 minutes at room temperature.
(200) C. Dialysis Protocol for Protein Refolding
(201) Prepare the required volume of buffer for dialysis of solubilized protein. The dialysis should be performed with at least 2 buffer changes of greater than 50 times the volume of the sample.
(202) Dilute the 50× Dialysis Buffer to 1× at the desired volume and supplement with 0.1 mM DTT.
(203) Dialyze for at least 4 hours at 4° C. Change the buffer and continue. Dialyze for an additional 4 or more hours.
(204) Prepare additional dialysis buffer as determined in step 1, but omit DTT.
(205) Continue the dialysis through two additional changes (minutes 4 hours each), with the dialysis buffer lacking DTT.
(206) D. Redox Folding Buffer to Promote Disulfide Bond Formation
(207) Prepare a dialysis buffer containing 1 mM reduced glutathione (1.2 g/4 L) and 0.2 mM oxidized glutathione (0.48 g/4 L) in 1× Dialysis Buffer. The volume should be 25 times greater than the volume of the solubilized protein sample. Chill to 4° C.
(208) Dialyze the refolded protein from step 1 overnight at 4° C.
(209) Materials for Purification
(210) All procedures are done at 4° C.
(211) Chemicals:
(212) Trizma Hydrochloride (Sigma T5941-500 G)
(213) Sodium Chloride 5M Solution (Sigma 56546-4 L)
(214) Sodium Hydroxide 10N (J T Baker 5674-02)
(215) E. Purification on the DEAE HiPrep 16/10 Anion Column-20 (GE Healthcare)
(216) Buffer A: 50 mM Tris-HCL pH 8.0
(217) Buffer B: 50 mM Tris-HCL with 1M NaCl pH 8.0
(218) Equilibration of column: Buffer A—5 CV, Buffer B—5 CV, Buffer A—10 CV
(219) Load 50 ml of sample per run on 20 ml column at 2.0 ml/min (NRG-156 (EGF-Id) is in the flow through).
(220) Wash 20 ml column with 5 CV of buffer A
(221) 20 ml column with gradient to 100% B with 5 CV. This is to elute off contamiants.
(222) Clean with 10 CV of 100% Buffer B.
(223) Equilibrate with 15 CV of Buffer A
(224) Analyze fractions with a SDS-page silver stain
(225) Pool fractions with NRG-156Q (10 kDa)
(226) F. Concentration of NRG-156 (EGF-Id)
(227) Concentrate with Millipore Centriprep 3000 MWCO 15 ml concentrator (Ultracel YN-3, 4320)
(228) Use Modified Lowry Protein Assay to determine concentration,
(229) G. His-Tag Removal
(230) Removal of the His-Tag is done with A Thrombin Cleavage Capture Kit from Novagen (Cat #69022-3). Based on previous testing the best conditions are room temperature for 4 hours with Thrombin at 0.005 U of enzyme per μl for every 1.0 μg of NRG-156Q (EGF-Id) protein. After four hours of incubation, add 16 μl of Streptavidin Agarose slurry per unit of Thrombin enzyme. Rock sample for 30 minutes at room temperature. Recover the NRG-156Q through spin-filtration or sterile filtering (depending on volume). Complete cleavage is determined with an EGF and Anti-His western.
(231) H. Storage in Final Buffer
(232) Stored in 1× PBS with 0.2% BSA at 4° C.
(233) Expression and Purification of GGF2
(234) For the cloning and background information for GGF2, see U.S. Pat. No. 5,530,109. The cell line is described in U.S. Pat. No. 6,051,401. The entire contents of each of U.S. Pat. Nos. 5,530,109 and 6,051,401 is incorporated herein by reference in its entirety.
(235) CHO-(Alpha2HSG)-GGF cell line: This cell line was designed to produce sufficient quantities of fetuin (human alpha2HSG to support high production rates of rhGGF2 in serum free conditions.
(236) Cho (dhfr-) cells were transfected with the expression vector shown in
(237) Stable and high producing cell lines were derived under standard protocols using methotrexate (100 nM, 200 nM, 400 nM, 1 μM) at 4-6 weeks intervals. The cells were gradually weaned from serum containing media. Clones were isolated by standard limiting dilution methodologies. Details of the media requirements are found in the above mentioned reports.
(238) To enhance transcription, the GGF2 coding sequence was placed after BMLF-1 intervening sequence (MIS). See diagrams at
(239) TABLE-US-00007 MIS Sequence (SEQ ID NO: 20) CGAT(AACTAGCAGCATTTCCTCCAACGAGGATCCCGCAG (GTAAGAAGCTACACCGGCCAGTGGCCGGGGGCC CGATAACTAGCAGCATTTCCTCCAACGAGGATCCCGCAG(GTAAGAAGCTACACCGGCC AGTGGCCGGGGCC GTGGAGCCGGGGGCATCCGGTGCCTGAGACAGAGGTGCTCAAGGCAGTCTCCACCTTTT GTCTCCCCTCTGCAG)AGAGCCACATTCTGGAA)GTT GGF2 coding sequence- (SEQ ID NO: 23) atgagatgg cgacgcgccc cgcgccgctc cgggcgtccc 301 ggcccccggg cccagcgccc cggctccgcc gcccgctcgc cgccgccgct gccgctgctg 361 ccactactgc tgctgctggg gaccgcggcc ctggcgccgg gggcggcggc cggcaacgag 421 gcggctcccg cgggggcctc ggtgtgctac tcgtccccgc ccagcgtggg atcggtgcag 481 gagctagctc agcgcgccgc ggtggtgatc gagggaaagg tgcacccgca gcggcggcag 541 cagggggcac tcgacaggaa ggcggcggcg gcggcgggcg aggcaggggc gtggggcggc 601 gatcgcgagc cgccagccgc gggcccacgg gcgctggggc cgcccgccga ggagccgctg 661 ctcgccgcca acgggaccgt gccctcttgg cccaccgccc cggtgcccag cgccggcgag 721 cccggggagg aggcgcccta tctggtgaag gtgcaccagg tgtgggcggt gaaagccggg 781 ggcttgaaga aggactcgct gctcaccgtg cgcctgggga cctggggcca ccccgccttc 841 ccctcctgcg ggaggctcaa ggaggacagc aggtacatct tcttcatgga gcccgacgcc 901 aacagcacca gccgcgcgcc ggccgccttc cgagcctctt tcccccctct ggagacgggc 961 cggaacctca agaaggaggt cagccgggtg ctgtgcaagc ggtgcgcctt gcctccccaa 1021 ttgaaagaga tgaaaagcca ggaatcggct gcaggttcca aactagtcct tcggtgtgaa 1081 accagttctg aatactcctc tctcagactc aagtggttca agaatgggaa tgaattgaat 1141 cgaaaaaaca aaccacaaaa tatcaagata caaaaaaagc cagggaagtc agaacttcgc 1201 attaacaaag catcactggc tgattctgga gagtatatgt gcaaagtgat cagcaaatta 1261 ggaaatgaca gtgcctctgc caatatcacc atcgtggaat caaacgctac atctacatcc 1321 accactggga caagccatct tgtaaaatgt gcggagaagg agaaaacttt ctgtgtgaat 1381 ggaggggagt gcttcatggt gaaagacctt tcaaacccct cgagatactt gtgcaagtgC 1441 ccaaatgagc ttactggtga tcgctgccaa aactacgtaa tggccagctt ctacagtacg 1501 tccactccct ttctgtctct gcctgaatag GGF2 Protein Sequence- (SEQ ID NO: 24) MRWRRAPRRSGRPGPRAQRPGSAARSSPPLPLLPLLLLLGTAAL APGAAAGNEAAPAGASVCYSSPPSVGSVQELAQRAAVVIEGKVHPQRRQQGALDRKAA AAAGEAGAWGGDREPPAAGPRALGPPAEEPLLAANGTVPSWPTAPVPSAGEPGEEAPY LVKVHQVWAVKAGGLKKDSLLTVRLGTWGHPAFPSCGRLKEDSRYIFFMEPDANSTSR APAAFRASFPPLETGRNLKKEVSRVLCKRCALPPQLKEMKSQESAAGSKLVLRCETSS EYSSLRFKWFKNGNELNRKNKPQNIKIQKKPGKSELRINKASLADSGEYMCKVISKLG NDSASANITIVESNATSTSTTGTSHLVKCAEKEKTFCVNGGECFMVKDLSNPSRYLCK CPNEFTGDRCQNYVMASFYSTSTPFLSLPE
(240) GGF2 production: One Vial of GGF2 at 2.2×10.sup.6 cells/mL was thawed into 100 mls of Acorda Medium (see Table 3) and expanded until reaching sufficient numbers to seed production vessels. Cells were inoculated into the production media Acorda Medium 2 (see Table 4) at 1.0×10.sup.5 cells/mL in two liter vented roller bottles. Roller bottles are maintained at 37° C. for 5 days and then reduced to 27° C. for 26 days. The roller bottles are monitored for cell count and general appearance but they are not fed. Once viability is below 10% the cells are spun out and conditioned media harvested and sterile filtered.
(241) TABLE-US-00008 TABLE 3 Medium 1 Catalog Item Vendor Number Final concentration CD-CHO Invitrogen 10743-029 remove 50 ml, then add components below FeSO.sub.4•EDTA Sigma F-0518 1x (100 ml/L) L-Glutamine Cellgro 25-005-CI 4 mM (20 ml/L) Recombinant Sigma I-9278 290 U/L (1 ml/L) Human Insulin Non-essential Cellgro 25-025-CI 1x (10 ml/L) amino acid Peptone Type 4 Sigma P0521 Powder - Made 20X in Soybean-HySoy CD-CHO (50 ml/L) Gentamicin Invitrogen 15750-078 100 μg (2 ml/L)
(242) TABLE-US-00009 TABLE 4 Medium 2 Catalog Item Vendor Number Final concentration CD-CHO Invitrogen 10743-029 50% (−50 ml first) HyQ SFX-CHO HyClone SH30187.02 50% (−50 ml first) FeSO.sub.4•EDTA Sigma F-0518 1x (10 ml/L) L-Gtutamine Cellgro 25-005-CI 4 mM (20 ml/L) Recombinant Sigma 1-9278 290 U/L (1 ml/L) Human Insulin Non-essential Cellgro 25-025-CI 1x (10 ml/L) amino acid Peptone Type 4 Sigma P0521 Powder - Made 20X in Soybean-HySoy CD-CHO (50 ml/L) Gentamicin Invitrogen 15750-078 100 μg (2 ml/L)
(243) Purification Protocol for GGF2
(244) All procedures are done at 4° C.
(245) Chemicals: Sodium Acetate Glacial Acetic Acid (for pH adjustment) 10N NaOH (for pH adjustment) NaCl Sodium Sulfate L-Arginine (J T Baker cat #: 2066-06) Mannitol (J T Baker cat #: 2553-01)
(246) Starting material: Conditioned media supernatant. Adjust pH to 6.5.
(247) Step 1:
(248) Capture—Cation Exchange Chropmatography HiPrep SP 16/10 (Amersham Biosciences) Column equilibration: Buffer A—5 CV, buffer B—5 CV, buffer 15% B—5 CV Buffer A: 20 mM NaAcetate, pH 6.0 Buffer B: 20 mM NaAcetate, pH 6.0, 1 M NaCl
(249) Load sample at 2 ml/min with a continuous load overnight if possible. Binding is better with continuous loading. Maximum capacity for a starting sample: 5 mg GGF2/ml media Flow rate-, 3 ml/min First wash: 15% B, 10 CV Second wash: 35% B, 10 CV GGF2 elution: 60% B, 8 CV Column wash: 100% B, 8 CV
(250) TABLE-US-00010 Conduc- Buffers: Composition tivity Use 15% B 20 mM NaAcetate, pH 6.0, 150 Preequilibra- mM NaCl tion First wash 35% B 20 mM NaAcetate, pH 6.0, 350 Second wash mM NaCl 60% B 20 mM NaAcetate, pH 6.0, 600 GGF2 elution mM NaCl 100% B 20 mM NaAcetate, pH 6.0, 1000 88 mS/cm Column wash mM NaCl
(251) Step 2:
(252) Refinement—Gel Filtration Chromatography Sephacryl S200 26/60 Elution buffer: 20 mM NaAcetate, 100 mM Sodium Sulfate, 1% mannitol, 10 mM L-Arginine, pH 6.5 Buffer conductivity: Sample: SP GGF2 elution pool concentrated up to ˜AU280 1.0 Flow rate: 1.3 ml/min Peak elution: at ˜0.36 CV from injection start
(253) Step 3: DNA and Endotoxin Removal—Filtration Through Intercept Q Membrane Preequilibration buffer: 20 mM NaAcetate, 100 mM Sodium Sulfate, 1% Mannitol, 10 mM L-Arginine, pH 6.5 Collect flow through
(254) Step 4; Final Formulation and Sample Preparation Add additional 90 mM L-Arginine to the sample Concentrate Sterile Filter
(255) The vehicle/control article used herein is 0.2% Bovine Serum Albumin (BSA), 0.1 M Sodium Phosphate, pH 7.6.
(256) Rat strains CD®IGS [Crl:CD®(SD)/MYOINFARCT] and Naive Sprague Dawley are used herein. These strains were acquired from Charles River Laboratories. The test animals are approximately 6-7 weeks of age at arrival and weigh approximately 160-200 g, at the time of surgical procedure. The actual range may vary and is documented in the data.
(257) All naive Sprague Dawley animals received were placed on study and assigned to Group 1. Animals considered suitable for study were weighed prior to treatment.
(258) All CD®IGS [Crl:CD®(SD)/MYOINFARCT] animals received were randomized into treatment groups (Groups 2-5) using a simple randomization procedure based on calculated Ejection Fraction from Echocardiographic examinations performed on Day 7 post surgical procedure conducted at Charles River Laboratories. Simple randomization was conducted to result in each treatment group (Groups 2-5) consisting of applicable numbers of animals resulting in an approximately equal Group Mean Ejection Fraction (±3%) across Group 2-5.
(259) All animals in Group 2-6 were acclimated at Charles River Laboratories according to Standard Operating Procedures of that laboratory. Animals were subsequently randomized into treatment groups. All naive animals in Group 1 were acclimated for approximately 24 hours post receipt prior to their primary Echocardiographic examinations.
(260) The animals were individually housed in suspended, stainless steel, wire-mesh type cages, Solid-bottom cages were not used in general because rodents are coprophagic and the ingestion of feces containing excreted test article and metabolic products or ingestion of the bedding itself could confound the interpretation of the results in this toxicity study.
(261) Fluorescent lighting was provided via an automatic timer for approximately 12 hours per day. On occasion, the dark cycle was interrupted intermittently due to study-related activities. Temperature and humidity were monitored and recorded daily and maintained to the maximum extent possible between 64 to 79° F. and 30 to 70%, respectively.
(262) The basal diet was block Lab Diet® Certified Rodent Diet #5002, PMI Nutrition International, Inc. This diet was available ad libitum unless designated otherwise. Each lot number used was identified in the study records. Tap water was supplied ad libitum to all animals via an automatic water system unless otherwise indicated.
(263) Study Designs
(264) TABLE-US-00011 TABLE 5 GGF2 versus EGF-Id fragment (Liu et al., 2006) Dosed for 10 days starting day 7 after LAD Dosing ECHO Time Group Treatment In-Life Duration Dose Interval† Points (post-op) 1 Control 17 days post-op Vehicle only 24 Hr Day 6, 17 (n = 5 M; n = 5 F) (Vehicle) 2 GGF2 17 days post 0.0625 mg/kg 24 Hr Day 6, 17 (n = 6 M; n = 6 F) 3 GGF2 17 days post 0.625 mg/kg 24 Hr Day 6, 17 (n = 6 M; n = 6 F) 4 EGF-Id 17 days post Equimolar 24 Hr Day 6, 17 (n = 6 M; n = 7 F) 5 EGF-Id 17 days post Equimolar 24 Hr Day 6, 17 (n = 7 M; n = 6 F)
(265) TABLE-US-00012 TABLE 6 GGF2 higher dose compared with EGF-Id and EGF-Ig Dosed for 20 days starting day 7 after LAD. 10 day washout. Dosing ECHO Time Group Treatment In-Life Duration Dose Interval† Points (post-op) 1 N/A: Age 30 days post NA NA ‡Day 1, 12, 22, (n = 5 M; n = 5 F) Matched Naïve primary ECHO & 32 controls 2 Control 38 days post-op Vehicle only 24 Hr *Day 7, 18, 28, (n = 6 M; n = 6 F) (Vehicle) & 38 3 GGF-2 38 days post-op 0.625 mg/kg 24 Hr *Day 7, 18, 28, (n = 6 M; n = 6 F) & 38 4 GGF-2 38 days post-op 3.25 mg/kg 24 Hr *Day 7, 18, 28, (n = 6 M; n = 7 F) & 38 5 EGF-Id 38 days post-op Equimolar 24 Hr *Day 7, 18, 28, (n = 7 M; n = 6 F) & 38 6 EGF-Id 38 days post-op Equimolar 24 Hr *Day 7, 18, 28, (n = 7 M; n = 6 F) & 38
(266) TABLE-US-00013 TABLE 7 GGF2 Dose frequency Dosing ECHO Time Group Treatment In-Life Duration Dose Interval† Points (post-op) 1 N/A: Age 30 days post NA NA ‡Day 1, 12, 22, (n = 5 M; n = 5 F) Matched Naïve primary ECHO & 32 controls 2 Control 38 days post-op Vehicle only 24 Hr *Day 7, 18, 28, (n = 6 M; n = 6 F) (Vehicle) & 38 3 GGF-2 38 days post-op 3.25 mg/kg 24 Hr *Day 7, 18, 28, (n = 6 M; n = 6 F) & 38 4 GGF-2 38 days post-op 3.25 mg/kg 48 Hr *Day 7, 18, 28, (n = 6 M; n = 7 F) & 38 5 GGF-2 38 days post-op 3.25 mg/kg 96 Hr *Day 7, 18, 28, (n = 7 M; n = 6 F) & 38 TA 1—Test Article 1; M = males; F = females.
(267) TABLE-US-00014 TABLE 8 GGF2 with and without BSA Dosing ECHO Time Group Treatment In-Life Duration Dose Interval† Points (post-op) 1 N/A: Age 17 days post-op NA NA Day 6 and 17 (n = 5 M; n = 5 F) Matched Naive controls 2 Control 17 days post Vehicle only 24 Hr Day 6 and 17 (n = 6 M; n = 6 F) (Vehicle) 3 GGF-2 + BSA 17 days post 3.25 mg/kg 24 Hr Day 6 and 17 (n = 6 M; n = 6 F) 4 GGF-2 without 17 days post 3.25 mg/kg 24 Hr Day 6 and 17 (n = 6 M; n = 7 F) BSA
(268) Test and Control Article Administration
(269) Route of Administration
(270) The test and control articles were administered by intravenous injection. Animals assigned to Group 1 were not treated with vehicle or Test Articles; these animals served as age matched controls without treatment. Frequency of administration, duration, and dose were as described in the Tables 5-8. The dose volume was approximately 1 ml per kg.
(271) Test Article Administration
(272) The test and control articles were administered via the tail vein. Individual doses were based on the most recent body weights. The dose was administered by bolus injection, unless otherwise indicated by the Sponsor,
(273) Preparation of Test System
(274) Surgical Procedure—Left Anterior Descending Artery Ligation
(275) The surgical procedures were performed at Charles River Laboratories as described in Charles River Laboratories Surgical Capabilities Reference Paper, Vol. 13, No. 1, 2005. Briefly, a cranio-caudal incision is made in the chest, slightly to the left of the sternum, through skin and the pectoral muscles. The third and forth ribs are transected, and the intercostals muscles are blunt dissected. The thoracic, cavity is rapidly entered, and the pericardium completely opened. The heart is exteriorized through the incision. The pulmonary cone and left auricle are identified. A small curved needle is used to pass a piece of 5-0 silk suture under the left anterior descending coronary artery. The ligature is tied, and the heart is replaced into the thorax. The air in the thoracic cavity is gently squeezed out while the thoracic wall and skin incision is closed. The animal is resuscitated using positive pressure ventilation and placed in an oxygen rich environment.
(276) Post—Operative Recovery
(277) Short term post-operative monitoring and administration of appropriate analgesics were performed by Charles River Laboratories as described in Charles River Laboratories Surgical Capabilities Reference Paper, Vol. 13, No. 1, 2005.
(278) Long term post-operative monitoring was conducted to assess the animals for signs of pain or infection. Daily incision site observations continued for 7 days post receipt of animals. Supplemental pain management and antimicrobial therapy were administered as necessitated.
(279) TABLE-US-00015 TABLE 9 SCHEDULED MEDICATIONS AND DOSAGES INTERVAL, DOSE, AND ROUTE DAY 32/38* DAILY DAY 1/7* DAY 12/18* DAY 22/28* ECHO & DRUG POSTSURGERY ECHO ECHO ECHO Necropsy Isoflurane — To effect, To effect, To effect, To effect, inhalation inhalation inhalation inhalation Buprenorphine 0.01 mg/kg, I.M. — — — — (only as needed) *ECHO procedure Day defined by animal Group assignment as indicated below.
(280) Antemortem Study Evaluations
(281) Cageside Observations
(282) All animals were observed at least twice a day for morbidity, mortality, injury, and availability of food and water. Any animals in poor health were identified for further monitoring and possible euthanasia.
(283) Body Weights
(284) Body weights were measured and recorded at least once prior to randomization and weekly during the study.
(285) Food Consumption
(286) Food consumption was not measured, but inappetence was documented.
(287) Echocardiographic Examinations
(288) Echocardiographic examinations were conducted on all animals assigned to Group 1 on Day 1, 12, 22 and Day 32 post receipt (Day 0). Echocardiographic examinations were conducted on all animals assigned to Group 2-5 on Day 7, 18, 28 and Day 38 post-surgical procedure conducted at Charles River Laboratories (Day 0).
(289) For the echocardiographic examination, each animal was anesthetized according to Table 5 and its hair clipped from the thorax. Coupling gel was applied to the echocardiographic transducer and image obtained to measure cardiac function at multiple levels. Images were obtained for each animal in short axis view (at mid-papillary level, or other depending on location of observed infarct area by echocardiography).
(290) Echocardiographic Parameters
(291) ECHO images were taken at the mid-papillary muscle level, or other depending on location of observed infarct area by echocardiography, of the left ventricle. M-mode and 2-D images were recorded and stored on CD and/or MOD. Measurement parameters obtained with ECHO include: lntraventricular Septal Wall Thickness (diastole); units=cm; Intravcntricular Septal Wall Thickness (systole); units=cm; Left Ventricular Internal Dimension (diastole); units=cm; Left Ventricular Internal Dimension (systole); units=cm; Left Ventricular Papillary Wall Thickness (diastole); units=cm; Left Ventricular Papillary Wall Thickness (systole); units=cm; End Diastolic Volume; units=mL; End Systolic Volume; units=mL; Ejection Fraction; reported as a percentage; Stroke Volume; units=ml; and Percent Fractional Shortening; reported as a percentage
(292) Euthanasia
(293) Moribundity
(294) Any moribund animals, as defined by a Testing Facility Standard Operating Procedure, were euthanized for humane reasons. All animals euthanized in extremis or found dead were subjected to a routine necropsy.
(295) Method of Euthanasia
(296) Euthanasia was performed by saturated potassium chloride injection into the vena cava followed by an approved method to ensure death, e.g. exsanguination.
(297) Final Disposition
(298) All surviving animals placed on study were euthanized at their scheduled necropsy or, if necessary, euthanized in extremis.
(299) Results
(300) Study 1—Treatment of Rats with GGF2 at 0.625 mg/kg iv qday resulted in significant improvement of cardiac function as shown here by changes in Ejection Fraction and Fractional Shortening. EGF-Id fragment did not result in the same degree of improvement. See Table 5.
(301) Study 2—Treatment of rats with GGF2 at 0.625 and 3.25 mg/kg iv qday resulted in significant improvement of cardiac function as shown here by changes in Ejection Fraction and Fractional Shortening. Significant improvements were also seen in end systolic and diastolic volumes during the treatment period. See Table 6.
(302) Study 3 Results—Treatment of Rats with GGF2 3.25 mg/kg iv q24, 48 or 96 hours resulted in significant improvement of cardiac function as shown here by changes in Ejection Fraction and Fractional Shortening. Significant improvements were also seen in end systolic and diastolic volumes during the treatment period. See Table 7.
(303) Previous reports (Liu et al) have shown that a carrier protein such as BSA is required for optimal neuregulin stability and activity. GGF2 has demonstrated stability without carriers such as BSA. This experiment was designed to test whether GGF2 is stable and active in a therapeutic regimen without BSA. After 10 days of treatment, both the BSA and non-BSA containing GGF2 formulations resulted in improvements in ejection fraction compared with vehicle controls similar to those seen in previous studies. It is, therefore, evident from this study that BSA or other carrier protein is not required in GGF2 formulations for the treatment of CHF. See Table 8.
(304) TABLE-US-00016 TABLE 10 Pathology findings Sciatic Nerve Sheath Injection Hyperplasia Mammary site/Skin Cardiac Dosing (NSH) NSH changes effects Daily s.c. ++ ++ ++ + Daily i.v. + + + +/− 48 hour interval i.v. +/− − − +/− 96 hour interval i.v. − − − − ++ frequently present; + present; +/− occasionally observed, − rare or not observed
(305) As shown in Table 10, intermittent dosing of GGF2 reduces side effects associated with supranormal levels of exogenously administered GGF2. The present inventors have discovered that this finding holds true irrespective of whether the GM is administered intravenously or subcutaneously.
(306) The hyperplasia and cardiac effects are sometimes seen with every other day dosing. We have not seen with less frequent dosing.
(307) Several publications and patent documents are referenced in this application in order to more fully describe the state of the art to which this invention pertains. All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each independent publication or patent application was specifically and individually indicated to be incorporated by reference.