ARCA biopharma Announces US FDA Acceptance of Gencaro Companion Diagnostic Test IDE

Phase 2B/3 GENETIC-AF Trial on Track to Begin Patient Enrollment in Q1 2014 Gencaro Potentially the First Genetically-Targeted Cardiovascular Treatment ARCA biopharma, Inc., a biopharmaceutical company developing genetically-targeted therapies for cardiovascular diseases, announced that Laboratory Corporation of America (LabCorp®) has informed ARCA that the U.S. Food and Drug Administration (FDA) has accepted LabCorp’s Investigational Device Exemption (IDE) application for the planned companion diagnostic test for Gencaro™ (bucindolol hydrochloride), a pharmacologically unique beta-blocker and mild vasodilator being developed for atrial fibrillation (AF). The IDE allows the companion diagnostic test to be used in the planned GENETIC-AF clinical trial. ARCA’s Gencaro Investigational New Drug (IND) application for AF has been accepted by the U.S. Food and Drug Administration (FDA) and is active. ARCA has identified common genetic variations that it believes predict individual patient response to Gencaro, giving it the potential to be the first genetically-targeted AF prevention treatment. LabCorp and ARCA have developed the companion diagnostic test for Gencaro to identify patient genotypes based on these genetic variations of the beta-1 cardiac receptor. LabCorp will provide the patient genetic testing for ARCA’s GENETIC-AF clinical trial of Gencaro, which is expected to begin patient enrollment in the first quarter of 2014. GENETIC-AF Clinical Trial GENETIC-AF is planned as a Phase 2B/3, multi-center, randomized, double-blind clinical trial comparing Gencaro to Toprol-XL for prevention of AF in patients with heart failure and reduced left ventricular ejection fraction (HFREF). ARCA plans to enroll only patients with the genetic variant of the beta-1 cardiac receptor which the Company believes responds most favorably to Gencaro. GENETIC-AF has an adaptive design, under which the Company plans to initiate it as a Phase 2B study in approximately 200 patients and then, depending on the results of an interim analysis by the trial Data Safety Monitoring Board (DSMB), expand the trial to a Phase 3 study by enrolling an estimated additional 420 patients. Medtronic, Inc. is collaborating with ARCA on the GENETIC-AF trial. The Company anticipates that patient enrollment in GENETIC-AF will begin in the first quarter of 2014. About ARCA biopharma ARCA biopharma is dedicated to developing genetically-targeted therapies for cardiovascular diseases. The Company's lead product candidate, GencaroTM (bucindolol hydrochloride), is an investigational, pharmacologically unique beta-blocker and mild vasodilator being developed for atrial fibrillation. ARCA has identified common genetic variations that it believes predict individual patient response to Gencaro, giving it the potential to be the first genetically-targeted atrial fibrillation prevention treatment. ARCA has a collaboration with Medtronic, Inc. for support of the GENETIC-AF trial. For more information please visit www.arcabiopharma.com.