ARCA biopharma and Medtronic to Collaborate on Atrial Fibrillation Clinical Trial for GencaroTM

  ARCA biopharma and Medtronic to Collaborate on Atrial Fibrillation Clinical
  Trial for GencaroTM

   Patients in Novel Clinical Trial Will Have Cardiac Rhythms Continuously
                  Monitored with Implanted Medtronic Devices

Business Wire

BROOMFIELD, Colo. -- April 22, 2013

ARCA biopharma, Inc. (Nasdaq: ABIO), a biopharmaceutical company developing
genetically-targeted therapies for cardiovascular diseases, today announced
that it has entered into an agreement with Medtronic, Inc. (NYSE:MDT), a
leader in medical technologies to improve the treatment of chronic diseases,
including cardiac rhythm disorders, to collaborate on ARCA’s proposed clinical
trial, known as GENETIC-AF, of its lead developmental drug Gencaro (bucindolol
hydrochloride).

GENETIC-AF is planned as a Phase 2b/3 clinical trial comparing Gencaro to
metoprolol CR/XL for prevention of atrial fibrillation (“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, expand the trial to a Phase 3 study by
enrolling an estimated additional 420 patients.

Under the collaboration, ARCA plans, with the support of Medtronic, to conduct
a substudy that will include continuous monitoring of the cardiac rhythms of
all 200 patients enrolled during the Phase 2b portion of GENETIC-AF. Each
patient will have heart rhythm monitoring via a Medtronic device, either a
previously implanted cardiac resynchronization or defibrillation device, or a
previously or newly inserted Reveal^® loop recorder. The collaboration
substudy will measure AF burden, defined as a patient’s actual time in AF
regardless of symptoms. In determining the presence of an efficacy signal in
the Phase 2b portion of the trial, AF burden will be evaluated along with time
to mortality or recurrent AF, which will also be the Phase 3 primary endpoint.

ARCA believes that the AF burden endpoint will help provide an accurate and
comprehensive assessment of each patient’s AF episodes, and will be useful in
evaluating the relative efficacies of Gencaro and metoprolol CR/XL. Under the
collaboration, Medtronic will support the implantation and use of the
Medtronic monitoring devices, and will manage the AF burden data collection
and analysis. If GENETIC-AF proceeds to Phase 3, the parties will seek to
enroll at least 100 additional patients in the AF burden substudy.

Dr. Michael Bristow, MD, PhD, President and Chief Executive Officer of ARCA,
said, “We are excited about our collaboration with Medtronic on GENETIC-AF. We
believe that the use of implanted, continuous monitoring devices that allow
for the more precise measurement of atrial fibrillation represents the next
generation of diagnosis and treatment options for patients at risk for this
disease. The GENETIC-AF trial has the potential to result in an approvable new
therapy that is safe and effective for HFREF patients at high risk for atrial
fibrillation.”

AF is considered an epidemic cardiovascular disease with an estimated
prevalence of at least 2.7 million Americans in 2010. The approved therapies
for the treatment or prevention of AF have certain disadvantages in HFREF
patients, such as toxic or cardiovascular adverse effects, and most of the
approved drugs for AF are contra-indicated or have warnings in their
prescribing information for such patients. ARCA believes there is an unmet
medical need for new AF treatments that have fewer side effects than currently
available therapies and are more effective, particularly in HFREF patients.

About ARCA biopharma

ARCA biopharma is dedicated to developing genetically-targeted therapies for
cardiovascular diseases. The Company's lead product candidate, Gencaro^TM
(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 the Laboratory Corporation of America (LabCorp), under
which LabCorp has developed a companion genetic test for Gencaro. For more
information please visit www.arcabiopharma.com.

Safe Harbor Statement

This press release contains "forward-looking statements" for purposes of the
safe harbor provided by the Private Securities Litigation Reform Act of 1995.
These statements include, but are not limited to, statements regarding the
potential for genetic variations to predict individual patient response to
Gencaro, Gencaro’s potential to treat atrial fibrillation, future treatment
options for patients with atrial fibrillation, the role of AF burden in
diagnosis and treatment of atrial fibrillation and the potential for Gencaro
to be the first genetically-targeted atrial fibrillation prevention treatment.
Such statements are based on management's current expectations and involve
risks and uncertainties. Actual results and performance could differ
materially from those projected in the forward-looking statements as a result
of many factors, including, without limitation, the risks and uncertainties
associated with: the Company's financial resources and whether they will be
sufficient to meet the Company's business objectives and operational
requirements; results of earlier clinical trials may not be confirmed in
future trials, the protection and market exclusivity provided by the Company’s
intellectual property; risks related to the drug discovery and the regulatory
approval process; and, the impact of competitive products and technological
changes. These and other factors are identified and described in more detail
in ARCA’s filings with the SEC, including without limitation the Company’s
annual report on Form 10-K for the year ended December 31, 2012, the Company’s
Registration Statement on Form S-1 (Registration No. 333-187508), and
subsequent filings. The Company disclaims any intent or obligation to update
these forward-looking statements.

Contact:

ARCA biopharma, Inc.
Derek Cole
Investor Relations Advisory Solutions
720-940-2163
derek.cole@arcabiopharma.com