Achillion Initiates Phase 2 Interferon-Free Trial of Sovaprevir and ACH-3102 for Genotype 1 HCV

Achillion Initiates Phase 2 Interferon-Free Trial of Sovaprevir and ACH-3102
for Genotype 1 HCV

All-Oral Trial to Evaluate the Safety and Efficacy of a 12-Week Regimen of
Sovaprevir, ACH-3102 and Ribavirin for Genotype 1 Treatment-Naive HCV Patients

NEW HAVEN, Conn., April 16, 2013 (GLOBE NEWSWIRE) -- Achillion
Pharmaceuticals, Inc. (Nasdaq:ACHN) today announced that it has initiated an
international Phase 2 clinical trial with sovaprevir and ACH-3102 for the
treatment of genotype 1 chronic hepatitis C (HCV). The trial will evaluate an
all-oral 12-week interferon-free regimen consisting of sovaprevir, ACH-3102,
and ribavirin in patients with chronic HCV who have not received prior

"With the initiation of this study, Achillion embarks on an aggressive and
robust Phase 2 program. In previous clinical trials, both sovaprevir and
ACH-3102 were shown to be efficacious, safe, well-tolerated, and had
demonstrated a high barrier to resistance. Hence, we believe that a
combination of these two agents for the treatment of chronic hepatitis C has
the potential to be well-tolerated and provide high SVR rates," commented
Milind Deshpande, Ph.D., President of Research and Development and Chief
Scientific Officer of Achillion.

"Based upon the highly competitive SVR rates achieved to date with sovaprevir
and the robust and unique single-agent activity observed with ACH-3102, our
cornerstone NS5A inhibitor, we are optimistic about the results from this
interferon-free trial," commented Michael Kishbauch, President and Chief
Executive Officer of Achillion. "Achillion looks forward to reporting all-oral
results from our ongoing clinical trials including RVR results from the -007
sovaprevir and ACH-3102 study during the third quarter of this year, as well
as providing the updated SVR results later this month from our safety and
tolerability study of ACH-3102 and ribavirin for the treatment of genotype 1b

Summary of Phase 2 '-007' Trial of Sovaprevir and ACH-3102

This is a Phase 2 trial which will evaluate the safety, tolerability and
efficacy of 12 weeks of sovaprevir, ACH-3102 and ribavirin in up to 50
treatment-naïve patients with chronic genotype 1 HCV. Initially, 30 patients
will be enrolled and randomized to receive either a combination of sovaprevir,
ACH-3102 and ribavirin or matching placebos. Once daily 200 mg or 400 mg doses
of sovaprevir with ACH-3102, given as a 150 mg loading dose followed by a 50
mg once daily dose, in combination with ribavirin, will be evaluated in this
trial. Primary endpoints include safety, tolerability, and sustained virologic
response 4 weeks after the completion of dosing (SVR4). The trial is expected
to enroll patients at sites in the United States, Canada, New Zealand and

About HCV

The hepatitis C virus is the most common cause of viral hepatitis, which is an
inflammation of the liver. It is currently estimated that more than 170
million people are infected with HCV worldwide including more than 5 million
people in the United States, more than twice as widespread as HIV.
Three-fourths of the HCV patient population is undiagnosed; it is a silent
epidemic and a major global health threat. Chronic hepatitis, if left
untreated, can lead to permanent liver damage that can result in the
development of liver cancer, liver failure or death. Few therapeutic options
currently exist for the treatment of HCV infection. The current standard of
care is limited by its specificity for certain types of HCV, significant
side-effect profile, and injectable route of administration.

About Achillion Pharmaceuticals

Achillion is an innovative pharmaceutical company dedicated to bringing
important new treatments to patients with infectious disease. Achillion's
proven discovery and development teams have advanced multiple product
candidates with novel mechanisms of action. Achillion is focused on solutions
for the most challenging problems in infectious disease including HCV and
resistant bacterial infections. For more information on Achillion
Pharmaceuticals, please visit or call 1-203-624-7000.

Forward-Looking Statements

This press release includes forward-looking statements within the meaning of
the Private Securities Litigation Reform Act of 1995 that are subject to
risks, uncertainties and other important factors that could cause actual
results to differ materially from those indicated by such forward-looking
statements, including statements with respect to: the potency, safety,
tolerability, effectiveness and other characteristics of sovaprevir and
ACH-3102; and Achillion's expectations regarding timing for the commencement,
completion and reporting of results of its -007 clinical trial of sovaprevir
and ACH-3102 in combination with ribavirin, as well as with respect to other
ongoing clinical studies. Among the factors that could cause actual results to
differ materially from those indicated by such forward-looking statements are
risks relating to, among other things Achillion's ability to: replicate in
later clinical trials positive results found in earlier stage clinical trials
of sovaprevir, ACH-3102 and its other product candidates; advance the
development of its drug candidates under the timelines it anticipates in
current and future clinical trials; obtain necessary regulatory approvals;
obtain patent protection for its drug candidates and the freedom to operate
under third party intellectual property; establish commercial manufacturing
arrangements; identify, enter into and maintain collaboration agreements with
appropriate third-parties; compete successfully with other companies that are
seeking to develop improved therapies for the treatment of HCV; manage
expenses; and raise the substantial additional capital needed to achieve its
business objectives. These and other risks are described in the reports filed
by Achillion with the U.S. Securities and Exchange Commission, including its
Annual Report on Form 10-K for the fiscal year ended December 31, 2012 and its
subsequent SEC filings.

In addition, any forward-looking statement in this press release represents
Achillion's views only as of the date of this press release and should not be
relied upon as representing its views as of any subsequent date. Achillion
disclaims any obligation to update any forward-looking statement, except as
required by applicable law.

CONTACT: Company Contact:
         Glenn Schulman
         Achillion Pharmaceuticals, Inc.
         Tel. (203) 624-7000
         Mary Kay Fenton
         Achillion Pharmaceuticals, Inc.
         Tel. (203) 624-7000
         Sally Barton
         Ogilvy PR
         Tel. (212)880-5240
         Seth Lewis
         The Trout Group, LLC
         Tel. (646) 378-2952
Press spacebar to pause and continue. Press esc to stop.