www.hivandhepatitis.com

Achillion Announces Start of Studies of ACH-3422 and ACH-3102 for Hepatitis C

Achillion Pharmaceuticalsannounced this week that the first participants have started receiving treatment in a Phase 1 clinical trial testing the investigational nucleotide hepatitis C virus (HCV) polymerase inhibitor ACH-3422. In addition, a recently initiated Phase 2 study is evaluating the company's next-generation NS5A inhibitor ACH-3012 in combination with Gilead Sciences' sofosbuvir (Sovaldi) for as little as 8 or even 6 weeks.

Below is an edited excerpt from an Achillion press release describing the studies in more detail.

Achillion Advances ACH-3422, Uridine-Analog Nucleotide Inhibitor, Into Clinical Trial; Initiates Phase 2 Pilot Study With ACH-3102, NS5A Inhibitor, for HCV

• Dosing Initiated in Phase 1 Study to Evaluate the Safety, Tolerability and Antiviral Activity of ACH-3422, NS5B Uridine-Analog Nucleotide Prodrug
• Initiated Phase 2 Study Evaluating ACH-3102, Second-Generation NS5A Inhibitor, with Sofosbuvir for 8 Weeks of Treatment or Less in Genotype 1 HCV Treatment-Naive Patients

New Haven, Conn. -- April 30, 2014 -- Achillion Pharmaceuticals, Inc. (Nasdaq:ACHN) today announced that is has begun dosing study participants with ACH-3422, Achillion's proprietary uridine-analog nucleotide inhibitor, in a Phase 1 clinical trial. ACH-3422 is being developed for use in combination regimens to treat chronic hepatitis C viral infection (HCV). Achillion also announced the initiation of dosing in a Phase 2 pilot study evaluating ACH-3102, Achillion's second-generation NS5A inhibitor, in combination with sofosbuvir for eight and potentially six weeks of treatment for patients with chronic genotype 1 treatment-naive HCV.

"We believe that a nucleotide inhibitor and NS5A combination is the cornerstone for pan-genotypic commercially competitive regimens, having demonstrated high response rates and short duration of therapy. With the addition of a third direct-acting antiviral such as a protease inhibitor, we believe we can potentially shorten therapy to less than eight weeks," commented Milind Deshpande, PhD, President and Chief Executive Officer of Achillion.

ACH-3422: Phase 1 Study in Healthy Subjects and Proof-of-Concept in HCV-infected Patients

Achillion is conducting a Phase 1 randomized, double-blind, placebo-controlled trial to investigate the safety, tolerability, pharmacokinetics and antiviral activity of ACH-3422. Cohorts of healthy subjects will be enrolled at each dose level to receive a single-ascending dose followed by multiple-ascending doses for 14 days. At each dose level, patients with treatment-naive genotype 1 HCV will receive 7 days of ACH-3422 to assess safety and antiviral activity. The starting dose in this trial will be 50 mg of ACH-3422 with the study expected to enroll a total of approximately 100 healthy volunteers and HCV-infected patients. Preliminary results, including safety and antiviral activity, are expected to be reported during the fall of 2014. This study is being conducted outside of the United States.

Dr. Deshpande further commented, "ACH-3422 has been rigorously evaluated in preclinical studies, which we believe support clinical advancement of ACH-3422. Preclinical data indicate that ACH-3422 has potency comparable to sofosbuvir against GT1 HCV, and has potency up to 7-fold higher against GT3 HCV. As we work to complete the healthy subject and HCV-infected patient cohorts in this ACH-3422 study, we are simultaneously exploring the characteristics of ACH-3102 in combination with sofosbuvir in a pilot trial that will evaluate an eight week or shorter treatment regimen and that we expect will be highly informative for initiation of combination studies of ACH-3422 and ACH-3102. We are eager to begin reporting preliminary results from these two programs starting late this summer and through the remainder of this year."

ACH-3102: Phase 2 Pilot Study Evaluating 8-week treatment in combination with sofosbuvir for genotype 1 treatment-naive HCV

Achillion is conducting a Phase 2, open-label, randomized, partial-crossover study to evaluate the efficacy, safety, and tolerability of eight weeks or six weeks of ACH-3102 and sofosbuvir in treatment-naive genotype 1 HCV-infected patients. The primary objective for the study is determination of sustained viral response 12 weeks (SVR12) after the completion of therapy. Twelve patients will be enrolled and receive eight weeks of treatment consisting of 50 mg of ACH-3102 and 400 mg of sofosbuvir administered once daily. The trial protocol also allows for the enrollment of additional HCV-infected patients who may be eligible to receive six weeks of treatment consisting of 50 mg of ACH-3102 and 400 mg of sofosbuvir administered once daily. Preliminary results from the eight-week treatment duration cohort are anticipated during the summer of 2014. This study is being conducted outside the United States.

David Apelian, MD, PhD, Executive Vice President and Chief Medical Officer commented, "Our focus is to safely and expeditiously advance our all-oral regimens for the treatment of HCV. The initiation of our first clinical study with our nucleotide inhibitor ACH-3422 is an important milestone for the Achillion portfolio. We expect that evaluation of our NS5A inhibitor ACH-3102 in combination with sofosbuvir will provide significant insights for our ultimate use of ACH-3422 and ACH-3102 in combination. Furthermore, we believe the breadth of our portfolio, which includes our protease inhibitors, could enable us to potentially develop commercially-competitive regimens that can be safe, effective, ribavirin-free and that can be used for eight weeks or less to potentially cure HCV."

About Achillion Pharmaceuticals

Achillion is an innovative pharmaceutical company dedicated to bringing important new treatments to patients with infectious disease. Achillion's discovery, clinical development, and commercial teams have advanced multiple novel product candidates with proven mechanisms of action into studies and toward the market. 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 www.achillion.com or call 1-203-624-7000.

5/2/14

Source

Achillion Pharmaceuticals. Achillion Advances ACH-3422, Uridine-Analog Nucleotide Inhibitor, Into Clinical Trial; Initiates Phase 2 Pilot Study With ACH-3102, NS5A Inhibitor, for HCV. Press release. April 30, 2014.