REGENERX BIOPHARMACEUTICALS, INC. (NYSE Amex:RGN) today reported on several clinical studies with Thymosin beta 4 (Tβ4) presented the Second International Symposium on Thymosins in Health and Disease, in Catania, Italy. The following are synopses of the presentations:
Myocardial Development of RGN-352 (Injectable Tβ4 Peptide)
David Crockford, RegeneRx’s vice president for clinical and regulatory affairs presented an overview of the biological properties that support Tβ4’s near term and long term clinical applications. Mr. Crockford noted that special emphasis is being placed on the development of RGN-352 for the systemic (injectable) treatment of patients with ST-elevation myocardial infarction (STEMI) in combination with percutaneous coronary intervention, the current standard of care in most western countries for this common type of heart attack. The goal with RGN-352 is to prevent or repair continued damage to cardiac tissue post-heart attack, when such tissue around the damaged site remains at risk.
Dr. Dennis Ruff, vice president and medical director of ICON, and principal investigator, presented the most current results on the Phase I safety study with RGN-352 entitled, “A Randomized, Double-blind, Placebo-controlled, Dose-response Phase I Study of the Safety and Tolerability of the Intravenous Administration of Thymosin Beta 4 and its Pharmacokinetics After Single and Multiple Doses in Healthy Volunteers.” Dr. Ruff discussed key aspects of the study and concluded with, “There were no dose limiting or serious adverse events throughout the dosing period. Synthetic Tβ4 administered intravenously up to 1260 mg, and for up to 14 days, appears to be well tolerated with low incidence of adverse events and no evidence of serious adverse events.”
http://www.news-medical.net/news/20091003/Clinical-study-data-of-Thymosin-beta-4-presented.aspx
RegeneRx Receives Notice of Allowance from Chinese Patent Office for Treatment and Prevention of Heart Disease
RegeneRx Receives Notice of Allowance from Chinese Patent Office for Treatment and Prevention of Heart Disease
February 7, 2013 — Rockville, Md.
RegeneRx Biopharmaceuticals, Inc. (OTC Bulletin Board: RGRX) (“the Company” or “RegeneRx”) today announced that it has received a Notice of Allowance of a Chinese patent application for uses of Thymosin beta 4 (TB4) for treating, preventing, inhibiting or reducing heart tissue deterioration, injury or damage in a subject with heart failure disease. Claims also include uses for restoring heart tissue in those subjects. The patent will expire July 26, 2026.
http://www.regenerx.com/wt/page/pr_1360265259
Active Research on Thymosins in Cardiovascular Disease Reported in 2010 and 2012 Annual Conference on Thymosins, Proceedings by NY Academy of Sciences
Use of the cardioprotectants thymosin β4 and dexrazoxane during congenital heart surgery: proposal for a randomized, double-blind, clinical trial
Neonates and infants undergoing heart surgery with cardioplegic arrest experience both inflammation and myocardial ischemia-reperfusion (IR) injury. These processes provoke myocardial apoptosis and oxygen-free radical formation that result in cardiac injury and dysfunction. Thymosin β4 (Tβ4) is a naturally occurring peptide that has cardioprotective and antiapoptotic effects. Similarly, dexrazoxane provides cardioprotection by reduction of toxic reactive oxygen species (ROS) and suppression of apoptosis. We propose a pilot pharmacokinetic/safety trial of Tβ4 and dexrazoxane in children less than one year of age, followed by a randomized, double-blind, clinical trial of Tβ4 or dexrazoxane versus placebo during congenital heart surgery. We will evaluate postoperative time to resolution of organ failure, development of low cardiac output syndrome, length of cardiac ICU and hospital stays, and echocardiographic indices of cardiac dysfunction. Results could establish the clinical utility of Tβ4 and/or dexrazoxane in ameliorating ischemia-reperfusion injury during congenital heart surgery.[1]
Cardiac repair with thymosin β4 and cardiac reprogramming factors
Heart disease is a leading cause of death in newborns and in adults. We previously reported that the G-actin–sequestering peptide thymosin β4 promotes myocardial survival in hypoxia and promotes neoangiogenesis, resulting in cardiac repair after injury. More recently, we showed that reprogramming of cardiac fibroblasts to cardiomyocyte-like cells in vivo after coronary artery ligation using three cardiac transcription factors (Gata4/Mef2c/Tbx5) offers an alternative approach to regenerate heart muscle. We have combined the delivery of thymosin β4 and the cardiac reprogramming factors to further enhance the degree of cardiac repair and improvement in cardiac function after myocardial infarction. These findings suggest that thymosin β4 and cardiac reprogramming technology may synergistically limit damage to the heart and promote cardiac regeneration through the stimulation of endogenous cells within the heart.[2]
NMR structural studies of thymosin α1 and β-thymosins
Thymosin proteins, originally isolated from fractionation of thymus tissue, represent a class of compounds that we now know are present in numerous other tissues, are unrelated to each other in a genetic sense, and appear to have different functions within the cell. Thymosin α1 (generic drug name thymalfasin; trade name Zadaxin) is derived from a precursor molecule, prothymosin, by proteolytic cleavage, and stimulates the immune system. Although the peptide is natively unstructured in aqueous solution, the helical structure has been observed in the presence of trifluoroethanol or unilamellar vesicles, and these studies are consistent with the presence of a dynamic helical structure whose sides are not completely hydrophilic or hydrophobic. This helical structure may occur in circulation when the peptide comes into contact with membranes. In this report, we discuss the current knowledge of the thymosin α1 structure and similar properties of thymosin β4 and thymosin β9, in different environments.[3]
Thymosin β4 sustained release from poly (lactide-co-glycolide) microspheres: synthesis and implications for treatment of myocardial ischemia
A sustained release formulation for the therapeutic peptide thymosin β4 (Tβ4) that can be localized to the heart and reduce the concentration and frequency of dose is being explored as a means to improve its delivery in humans. This review contains concepts involved in the delivery of peptides to the heart and the synthesis of polymer microspheres for the sustained release of peptides, including Tβ4. Initial results of poly(lactic-co-glycolic acid) microspheres synthesized with specific tolerances for intramyocardial injection that demonstrate the encapsulation and release of Tβ4 from double-emulsion microspheres are also presented.[4]
Thymosin β4 and cardiac repair
Hypoxic heart disease is a predominant cause of disability and death worldwide. As adult mammals are incapable of cardiac repair after infarction, the discovery of effective methods to achieve myocardial and vascular regeneration is crucial. Efforts to use stem cells to repopulate damaged tissue are currently limited by technical considerations and restricted cell potential. We discovered that the small, secreted peptide thymosin β4 (Tβ4) could be sufficiently used to inhibit myocardial cell death, stimulate vessel growth, and activate endogenous cardiac progenitors by reminding the adult heart on its embryonic program in vivo. The initiation of epicardial thickening accompanied by increase of myocardial and epicardial progenitors with or without infarction indicate that the reactivation process is independent of injury. Our results demonstrate Tβ4 to be the first known molecule able to initiate simultaneous myocardial and vascular regeneration after systemic administration in vivo. Given our findings, the utility of Tβ4 to heal cardiac injury may hold promise and warrant further investigation.[7]
Thymosin β4 facilitates epicardial neovascularization of the injured adult heart
Ischemic heart disease complicated by coronary artery occlusion causes myocardial infarction (MI), which is the major cause of morbidity and mortality in humans (
http://www.who.int/cardiovascular_diseases/resources/atlas/en/index.html). After MI the human heart has an impaired capacity to regenerate and, despite the high prevalence of cardiovascular disease worldwide, there is currently only limited insight into how to stimulate repair of the injured adult heart from its component parts. Efficient cardiac regeneration requires the replacement of lost cardiomyocytes, formation of new coronary blood vessels, and appropriate modulation of inflammation to prevent maladaptive remodeling, fibrosis/scarring, and consequent cardiac dysfunction. Here we show that thymosin β4 (Tβ4) promotes new vasculature in both the intact and injured mammalian heart. We demonstrate that limited EPDC-derived endothelial-restricted neovascularization constitutes suboptimal “endogenous repair,” following injury, which is significantly augmented by Tβ4 to increase and stabilize the vascular plexus via collateral vessel growth. As such, we identify Tβ4 as a facilitator of cardiac neovascularization and highlight adult EPDCs as resident progenitors which, when instructed by Tβ4, have the capacity to sustain the myocardium after ischemic damage.[8]
Thymosin β4 enhances repair by organizing connective tissue and preventing the appearance of myofibroblasts
Incisional wounds in rats treated locally with thymosin β4 (Tβ4) healed with minimal scaring and without loss in wound breaking strength. Treated wounds were significantly narrower in width. Polarized light microscopy treated wounds had superior organized collagen fibers, displaying a red birefringence, which is consistent with mature connective tissue. Control incisions had randomly organized collagen fibers, displaying green birefringence that is consistent with immature connective tissue. Immunohistology treated wounds had few myofibroblasts and fibroblasts with α smooth muscle actin (SMA) stained stress fibers. Polyvinyl alcohol sponge implants placed in subcutaneous pockets received either carrier or 100 μg of Tβ4 on days 2, 3, and 4. On day 14, treated implants revealed longer, thicker collagen fiber bundles with intense yellow-red birefringence by polarized light microscopy. In controls, fine, thin collagen fiber bundles were arranged in random arrays with predominantly green birefringence. Controls contained mostly myofibroblasts, while few myofibroblasts appeared in Tβ4 treated implants. Electron microscopy confirmed both cell types and the degree of collagen fiber bundle organization. Our results demonstrate that Tβ4 treated wounds appear to mature earlier and heal with minimal scaring.[9]
Thymosin β4: a key factor for protective effects of eEPCs in acute and chronic ischemia
Acute myocardial infarction is still one of the leading causes of death in the industrial nations. Even after successful revascularization, myocardial ischemia results in a loss of cardiomyocytes and scar formation. Embryonic EPCs (eEPCs), retroinfused into the ischemic region of the pig heart, provided rapid paracrine benefit to acute and chronic ischemia in a PI-3K/Akt-dependent manner. In a model of acute myocardial ischemia, infarct size and loss of regional myocardial function decreased after eEPC application, unless cell pre-treatment with thymosin β4 shRNA was performed. Thymosin ß4 peptide retroinfusion mimicked the eEPC-derived improvement of infarct size and myocardial function. In chronic ischemia (rabbit model), eEPCs retroinfused into the ischemic hindlimb enhanced capillary density, collateral growth, and perfusion. Therapeutic neovascularization was absent when thymosin ß4 shRNA was introduced into eEPCs before application. In conclusion, eEPCs are capable of acute and chronic ischemia protection in a thymosin ß4 dependent manner. [10]
Thymosin β4: a candidate for treatment of stroke?
Neurorestorative therapy is the next frontier in the treatment of stroke. An expanding body of evidence supports the theory that after stroke, certain cellular changes occur that resemble early stages of development. Increased expression of developmental proteins in the area bordering the infarct suggest an active repair or reconditioning response to ischemic injury. Neurorestorative therapy targets parenchymal cells (neurons, oligodendrocytes, astrocyes, and endothelial cells) to enhance endogenous neurogenesis, angiogenesis, axonal sprouting, and synaptogenesis to promote functional recovery. Pharmacological treatments include statins, phosphodiesterase 5 inhibitors, erythropoietin, and nitric oxide donors that have all improved funtional outcome after stroke in the preclinial arena. Thymosin β4 (Tβ4) is expressed in both the developing and adult brain and it has been shown to stimulate vasculogenesis, angiogenesis, and arteriogenesis in the postnatal and adult murine cardiac myocardium. In this manuscript, we describe our rationale and techniques to test our hypothesis that Tβ4 may be a candidate neurorestorative agent. [11]
Prothymosin α as robustness molecule against ischemic stress to brain and retina
Following stroke or traumatic damage, neuronal death via both necrosis and apoptosis causes loss of functions, including memory, sensory perception, and motor skills. As necrosis has the nature to expand, while apoptosis stops the cell death cascade in the brain, necrosis is considered to be a promising target for rapid treatment for stroke. We identified the nuclear protein, prothymosin alpha (ProTα) from the conditioned medium of serum-free culture of cortical neurons as a key protein-inhibiting necrosis. In the culture of cortical neurons in the serum-free condition without any supplements, ProTα inhibited the necrosis, but caused apoptosis. In the ischemic brain or retina, ProTα showed a potent inhibition of both necrosis and apoptosis. By use of anti-brain-derived neurotrophic factor or anti-erythropoietin IgG, we found that ProTα inhibits necrosis, but causes apoptosis, which is in turn inhibited by ProTα-induced neurotrophins under the condition of ischemia. From the experiment using anti-ProTα IgG or antisense oligonucleotide for ProTα, it was revealed that ProTα has a pathophysiological role in protecting neurons in stroke.[12]
Thymosin β4 and cardiac repair
Hypoxic heart disease is a predominant cause of disability and death worldwide. As adult mammals are incapable of cardiac repair after infarction, the discovery of effective methods to achieve myocardial and vascular regeneration is crucial. Efforts to use stem cells to repopulate damaged tissue are currently limited by technical considerations and restricted cell potential. We discovered that the small, secreted peptide thymosin β4 (Tβ4) could be sufficiently used to inhibit myocardial cell death, stimulate vessel growth, and activate endogenous cardiac progenitors by reminding the adult heart on its embryonic program in vivo. The initiation of epicardial thickening accompanied by increase of myocardial and epicardial progenitors with or without infarction indicate that the reactivation process is independent of injury. Our results demonstrate Tβ4 to be the first known molecule able to initiate simultaneous myocardial and vascular regeneration after systemic administration in vivo. Given our findings, the utility of Tβ4 to heal cardiac injury may hold promise and warrant further investigation.[13]
Thymosin β4 facilitates epicardial neovascularization of the injured adult heart
schemic heart disease complicated by coronary artery occlusion causes myocardial infarction (MI), which is the major cause of morbidity and mortality in humans (
http://www.who.int/cardiovascular_diseases/resources/atlas/en/index.html). After MI the human heart has an impaired capacity to regenerate and, despite the high prevalence of cardiovascular disease worldwide, there is currently only limited insight into how to stimulate repair of the injured adult heart from its component parts. Efficient cardiac regeneration requires the replacement of lost cardiomyocytes, formation of new coronary blood vessels, and appropriate modulation of inflammation to prevent maladaptive remodeling, fibrosis/scarring, and consequent cardiac dysfunction. Here we show that thymosin β4 (Tβ4) promotes new vasculature in both the intact and injured mammalian heart. We demonstrate that limited EPDC-derived endothelial-restricted neovascularization constitutes suboptimal “endogenous repair,” following injury, which is significantly augmented by Tβ4 to increase and stabilize the vascular plexus via collateral vessel growth. As such, we identify Tβ4 as a facilitator of cardiac neovascularization and highlight adult EPDCs as resident progenitors which, when instructed by Tβ4, have the capacity to sustain the myocardium after ischemic damage. [14]
Thymosin β4: a key factor for protective effects of eEPCs in acute and chronic ischemia
Acute myocardial infarction is still one of the leading causes of death in the industrial nations. Even after successful revascularization, myocardial ischemia results in a loss of cardiomyocytes and scar formation. Embryonic EPCs (eEPCs), retroinfused into the ischemic region of the pig heart, provided rapid paracrine benefit to acute and chronic ischemia in a PI-3K/Akt-dependent manner. In a model of acute myocardial ischemia, infarct size and loss of regional myocardial function decreased after eEPC application, unless cell pre-treatment with thymosin β4 shRNA was performed. Thymosin ß4 peptide retroinfusion mimicked the eEPC-derived improvement of infarct size and myocardial function. In chronic ischemia (rabbit model), eEPCs retroinfused into the ischemic hindlimb enhanced capillary density, collateral growth, and perfusion. Therapeutic neovascularization was absent when thymosin ß4 shRNA was introduced into eEPCs before application. In conclusion, eEPCs are capable of acute and chronic ischemia protection in a thymosin ß4 dependent manner.[15]
Thymosin β4: a candidate for treatment of stroke?
Neurorestorative therapy is the next frontier in the treatment of stroke. An expanding body of evidence supports the theory that after stroke, certain cellular changes occur that resemble early stages of development. Increased expression of developmental proteins in the area bordering the infarct suggest an active repair or reconditioning response to ischemic injury. Neurorestorative therapy targets parenchymal cells (neurons, oligodendrocytes, astrocyes, and endothelial cells) to enhance endogenous neurogenesis, angiogenesis, axonal sprouting, and synaptogenesis to promote functional recovery. Pharmacological treatments include statins, phosphodiesterase 5 inhibitors, erythropoietin, and nitric oxide donors that have all improved funtional outcome after stroke in the preclinial arena. Thymosin β4 (Tβ4) is expressed in both the developing and adult brain and it has been shown to stimulate vasculogenesis, angiogenesis, and arteriogenesis in the postnatal and adult murine cardiac myocardium. In this manuscript, we describe our rationale and techniques to test our hypothesis that Tβ4 may be a candidate neurorestorative agent.[16]
Thymosin β4: structure, function, and biological properties supporting current and future clinical applications
Published studies have described a number of physiological properties and cellular functions of thymosin β4 (Tβ4), the major G-actin-sequestering molecule in mammalian cells. Those activities include the promotion of cell migration, blood vessel formation, cell survival, stem cell differentiation, the modulation of cytokines, chemokines, and specific proteases, the upregulation of matrix molecules and gene expression, and the downregulation of a major nuclear transcription factor. Such properties have provided the scientific rationale for a number of ongoing and planned dermal, corneal, cardiac clinical trials evaluating the tissue protective, regenerative and repair potential of Tβ4, and direction for future clinical applications in the treatment of diseases of the central nervous system, lung inflammatory disease, and sepsis. A special emphasis is placed on the development of Tβ4 in the treatment of patients with ST elevation myocardial infarction in combination with percutaneous coronary intervention.[17]
The effect of thymosin treatment of venous ulcers
Venous ulcers are responsible for about 70% of the chronic ulcers of the lower limbs. Standard of care includes compression, dressings, debridement of devitalized tissue, and infection control. Thymosin beta 4 (Tβ4), a synthetic copy of the naturally occurring 43 amino-acid peptide, has been found to have wound healing and anti-inflammatory properties, and is thought to exert its therapeutic effect through promotion of keratinocyte and endothelial cell migration, increased collagen deposition, and stimulation of angiogenesis. To assess the safety, tolerability, and efficacy of topically administered Tβ4 in patients with venous stasis ulcers, a double-blind, placebo-controlled, dose-escalation study was conducted in eight European sites (five in Italy and three in Poland) that enrolled and randomized 73 patients. The safety profile of all doses of administered Tβ4 was deemed acceptable and comparable to placebo. Efficacy findings from this Phase 2 study suggest that a Tβ4 dose of 0.03% may have the potential to accelerate wound healing and that complete wound healing can be achieved within 3 months in about 25% of the patients, especially among those whose wounds are small to moderate in size or mild to moderate in severity.[18]
A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin β4 in healthy volunteers
Synthetic thymosin beta 4 (Tβ4) may have a potential use in promoting myocardial cell survival during acute myocardial infarction. Four cohorts, with 10 healthy subjects each, were given a single intravenous dose of placebo or synthetic Tβ4. Cohorts received ascending doses of either 42, 140, 420, or 1260 mg. Following safety review, subjects were given the same dose regimen daily for 14 days. Safety evaluations, incidence of Treatment-Emergent Adverse Events, and pharmacokinetic parameters were evaluated. Adverse events were infrequent, and mild or moderate in intensity. There were no dose limiting toxicities or serious adverse events. Pharmacokinetic profile for single dose showed a dose proportional response, and an increasing half-life with increasing dose. Synthetic Tβ4 given intravenously as a single dose or in multiple daily doses for 14 days over a dose range of 42–1260 mg was well tolerated with no evidence of dose limiting toxicity. Further development for use in cardiac ischemia should be considered.[19]
2012pharmaceutical
Amandeep Kaur
Aashir Awan, Phd
Abhisar Anand
Adina Hazan
Alan F. Kaul, PharmD., MS, MBA, FCCP
alexcrystal6
anamikasarkar
apreconasia
aviralvatsa
David Orchard-Webb, PhD
danutdaagmailcom
Demet Sag, Ph.D., CRA, GCP
Dror Nir
dsmolyar
Ethan Coomber
evelinacohn
Gail S Thornton
Irina Robu
jayzmit48
jdpmd
jshertok
kellyperlman
Ed Kislauskis
larryhbern
Madison Davis
marzankhan
megbaker58
ofermar2020
Dr. Pati
pkandala
ritusaxena
Rick Mandahl
sjwilliamspa
Srinivas Sriram
stuartlpbi
Dr. Sudipta Saha
tildabarliya
vaishnavee24
zraviv06
zs22