Repligen Initiates Phase 2b Clinical Trial Of RG2417 In Bipolar Disorder

Repligen Corporation
(Nasdaq: RGEN) announced that the Company has initiated a Phase 2b
clinical trial to evaluate the use of RG2417, an oral formulation of
uridine, in patients with bipolar depression. This Phase 2b study is a
multi-center, randomized, double-blind, placebo-controlled clinical trial
in which approximately 150 patients with bipolar depression will receive
either RG2417 or placebo twice daily for eight weeks. This study is
designed to assess the safety and efficacy of RG2417 as measured by the
Montgomery-Asberg Depression Rating Scale (MADRS) and the Clinical Global
Impression of Change in Bipolar Disorder Scale (CGI-BP-C). The study will
be conducted at approximately 20 clinical sites within the United States.
The Principal Investigator of this study is Gary S. Sachs, M.D., founder
and director of the Bipolar Clinic and Research Program at the
Massachusetts General Hospital and an Associate Professor of Psychiatry at
the Harvard Medical School.



"Episodes of depression are the most frequent and long-lived symptom of
bipolar disorder and account for the majority of the disease impairment.
Current therapies used to treat bipolar depression are often ineffective
and may have significant side effects, resulting in bipolar depression as
an area of high unmet medical need," said Walter C. Herlihy, President and
Chief Executive Officer of Repligen. "We look forward to confirming our
prior results with RG2417 in bipolar depression in this larger
proof-of-concept clinical trial."



The trial is designed to confirm and extend the results obtained in a
positive Phase 2a clinical trial of RG2417 in which 83 patients with
bipolar disorder received either RG2417 or placebo twice daily for six
weeks. The Phase 2a trial demonstrated a statistically significant
reduction in the symptoms of depression in patients receiving RG2417 when
compared to placebo on the MADRS (p=0.01) and on the CGI-BP-C (p=0.044)
over the six-week course of the study. The data also demonstrated that
RG2417 was safe and well tolerated. This study was partially supported by
the Stanley Medical Research Institute, the largest nonprofit provider of
funding for research on schizophrenia and bipolar disorder in the United
States.



About Bipolar Disorder



Bipolar disorder, also known as manic depression, is an illness marked
by extreme changes in mood, thought, energy and behavior in which a
person's mood alternates between the "poles" of mania (highs) and
depression (lows). Bipolar disorder affects more than two million adults in
the United States and is usually diagnosed in late adolescence or early
adulthood. Bipolar disorder is a chronic illness associated with
substantial morbidity and mortality, ranking worldwide behind only unipolar
depression and alcohol abuse among psychiatric illnesses for related
disabilities and overall economic burden of illness. The average lifetime
financial burden of bipolar disorder in the United States is about $625,000
per patient. Although lithium and anticonvulsants such as valproic acid
have substantially improved the prognosis of bipolar disorder, many
individuals are unable to tolerate treatment-related side effects, and
incomplete clinical response, lack of compliance in taking medication, and
relapse remain common clinical problems.
















About Repligen Corporation



Repligen Corporation is a biopharmaceutical company focused on the
development of novel therapeutics for neurological disorders. In addition,
we are the world's leading supplier of recombinant Protein A, the sales of
which partially fund the advancement of our development pipeline while
supporting our financial stability. Repligen's corporate headquarters are
located at 41 Seyon Street, Building #1, Suite 100, Waltham, MA 02453.
Additional information may be requested from repligen.



This press release contains forward-looking statements which are made
pursuant to the safe harbor provisions of Section 27A of the Securities Act
of 1933, as amended, and Section 21E of the Securities Exchange Act of
1934, as amended. The forward-looking statements in this release do not
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objectives for future operations, plans and objectives for product
development, plans and objectives for present and future clinical trials
and results of such trials, plans and objectives for regulatory approval,
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and performance such as the anticipated growth in the monoclonal antibody
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constitute forward-looking statements. Such forward-looking statements are
subject to a number of risks and uncertainties that could cause actual
results to differ materially from those anticipated, including, without
limitation, risks associated with: the success of current and future
collaborative relationships, the market acceptance of our products, our
ability to compete with larger, better financed pharmaceutical and
biotechnology companies, new approaches to the treatment of our targeted
diseases, our expectation of incurring continued losses, our uncertainty of
product revenues and profits, our ability to generate future revenues, our
ability to raise additional capital to continue our drug development
programs, the success of our clinical trials, our ability to develop and
commercialize products, our ability to obtain required regulatory
approvals, our compliance with all Food and Drug Administration
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capabilities, our dependence on third-party manufacturers and value added
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update any forward-looking information contained in this press release or
with respect to the announcements described herein.


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