PhaseBio Receives FDA Orphan Drug Designation for Vasomera (PB1046) for the Treatment of Cardiomyopathy Associated with Dystrophinopathies

Malvern, PA, December 1, 2015 — PhaseBio Pharmaceuticals, Inc., a clinical-stage biopharmaceutical company and leader in the field of biopolymer-based drugs, focused on developing treatments for metabolic and specialty cardiopulmonary disorders, today announced that the U.S. Food and Drug Administration (FDA) has granted orphan drug designation to Vasomera (PB1046) Injection for the treatment of cardiomyopathy associated with dystrophinopathies: Duchenne muscular dystrophy (DMD), Becker muscular dystrophy (BMD) and X-linked dilated cardiomyopathy (XL-dCMP). Dystrophinopathies are rare heterogeneous X-linked genetic disorders characterized by progressive muscle tissue degeneration caused by mutations in the dystrophin gene. As current treatment has focused on prevention of skeletal muscle loss and preservation of respiratory function, cardiomyopathy has emerged as a leading cause of death.


PhaseBio plans to initiate a Phase 2a study of PB1046 in the first quarter of 2016. The study will be conducted in two parts. Part One will be a double-blind, placebo-controlled, sequential dose escalation study to assess safety, tolerability, pharmacokinetics (PK) and explore pharmacodynamic (PD) response following four weeks of dosing with PB1046 in approximately 20 patients with stable New York Heart Association (NYHA) Class II/III heart failure with reduced ejection fraction. Two doses will be selected to move forward to Part Two, which will assess the safety, PK and explore PD response in approximately 20 patients with DMD or BMD who have evidence of cardiac dysfunction.

“Orphan drug designation is an important regulatory milestone for PB1046 and PhaseBio, and highlights the need for therapies to treat cardiomyopathy associated with dystrophinopathies, a life-threatening condition with no adequate therapy options,” said Jonathan P. Mow, Chief Executive Officer of PhaseBio. “We are on track to advance PB1046 into the Phase 2a study early next year and look forward to continuing to work with the FDA to meet this critical patient need.”

The Orphan Drug Designation program is intended to encourage companies to develop therapeutics for diseases that affect fewer than 200,000 individuals in the U.S. Orphan drug designation will provide PB1046 with seven years of marketing exclusivity if approved by the FDA for the treatment of dystrophic cardiomyopathy. Prior to FDA approval, orphan drug designation provides incentives for sponsors, including tax credits for clinical research expenses, the opportunity to obtain government grant funding to support clinical research and an exemption from FDA user fees.

PB1046 has also received orphan drug designation for the treatment of World Health Organization (WHO) group I Pulmonary Arterial Hypertension.

About PB1046

PB1046 is based on Vasoactive Intestinal Peptide (VIP), a naturally occurring neuropeptide that exerts its physiological effects through activation of G protein-coupled receptors VPAC1 and VPAC2, which are widely distributed throughout the cardiovascular, pulmonary and immune systems. To date, the inherently poor in vivo stability and bioavailability of the native peptide have precluded its therapeutic use. PhaseBio is developing PB1046 as a genetic fusion of an analogue of VIP with its ELP biopolymer, which overcomes these limitations and demonstrates prolonged circulatory drug exposure and potent activity.

PB1046 was designed to be relatively selective for binding to the VPAC2 receptor to reduce potential gastrointestinal side effects believed to be associated with excessive activation of the VPAC1 receptor. PB1046 has been shown to be highly effective in pre-clinical studies of hypertension, pulmonary arterial hypertension and in multiple heart failure models, with positive cardiac inotropic (contractility) and lusitropic (relaxation) effects without an increase in myocardial oxygen demand.

Pre-clinical data also demonstrated that chronic administration of PB1046 in a murine model of DMD (mdx mouse) significantly slowed the deterioration of cardiac function (fractional area shortening and E/A ratios). Treated animals showed preserved dP/dtmax (contraction) and faster Tau (relaxation). In skeletal muscles of the mice, PB1046 protected against contraction-induced damage and the degree of fibrosis (as determined by collagen deposition) was reduced in both cardiac muscle and skeletal muscles (gastrocnemius). Proof of concept was established on the safety, PK and hemodynamic activity measured directly by means of changes in blood pressure as a surrogate following single subcutaneous and intravenous administration of PB1046 in two clinical trials conducted in volunteers with essential hypertension.

About PhaseBio

PhaseBio Pharmaceuticals is a clinical-stage biopharmaceutical company developing novel drugs to treat metabolic and specialty cardiopulmonary disorders. The Company’s proprietary technology platform uses recombinant elastin-like polypeptide (ELP) biopolymers to control the half-life, bioavailability and physical characteristics of molecules for ease of administration. The resulting compounds are engineered for a specific rate of absorption to enhance efficacy and reduce side effects. PhaseBio’s lead development candidates include: PE0139, a novel, super-long-acting basal insulin-ELP fusion for once-weekly dosing; and PB1046, a weekly vasoactive intestinal peptide receptor agonist for the treatment of acute and chronic heart failure, the treatment of cardiomyopathy associated with Duchenne muscular dystrophy, Becker muscular dystrophy and X-linked dilated cardiomyopathy, and other indications. PhaseBio is privately owned with headquarters and research laboratories in Malvern, PA.



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