Merck's boceprevir Phase III studies for HCV to be presented at 61st AASLD

Merck today announced that final results from two pivotal Phase III studies of boceprevir, its investigational oral hepatitis C protease inhibitor, will be presented in oral plenary sessions at the 61^st Annual Meeting of the American Association for the Study of Liver Diseases (AASLD), which is taking place from Oct. 29 through Nov. 2 in Boston. Results for boceprevir in response-guided therapy strategies, which evaluated treatment durations shorter than current standard therapy, will be presented during the meeting. In total, more than 20 oral and poster presentations of clinical studies highlighting Merck medicines and investigational therapies for chronic hepatitis C virus (HCV) infection will be presented.

“What are the possible side effects of PegIntron and PegIntron/REBETOL combination therapy?”

Boceprevir, in combination with PEGINTRON^® (peginterferon alfa-2b) and REBETOL^® (ribavirin, USP) (Peg/riba), is being studied for the treatment of patients with HCV genotype 1 infection who were previously treated (treatment-failure; HCV RESPOND-2) and in patients who are new to treatment (treatment-naïve; HCV SPRINT-2).

As previously reported, Merck plans to submit a New Drug Application (NDA) for boceprevir to the U.S. Food and Drug Administration (FDA) on a rolling basis, and expects to complete regulatory submissions in the U.S. and E.U. in 2010.

The AASLD presentations of the boceprevir Phase III data will include sustained virologic response (SVR)¹ rates by patient sub-groups, including treatment-naïve patients (African-American/Black and non-African-American/Black), patients who experienced prior relapse, prior non-responders, and patients with a poor response to interferon, defined as having achieved less than a 1 log decrease in viral load (HCV-RNA) after a 4-week Peg/riba lead-in period.

The HCV RESPOND-2 and HCV SPRINT-2 studies each evaluated two treatment strategies with boceprevir to assess the ability to improve SVR and potentially shorten overall treatment duration compared to Peg/riba alone:

• Response-guided therapy, in which treatment-failure patients with undetectable virus at week 8 were able to stop all treatment at 36 weeks, and in which treatment-naïve patients with undetectable virus during weeks 8 through 24 were able to stop all treatment at 28 weeks; and
• 48 weeks of treatment (4-week Peg/riba lead-in followed by the addition of boceprevir for 44 weeks).

In both studies, all patients were treated with a 4-week lead-in of PEGINTRON (1.5 mcg/kg/week) and an investigational dose of REBETOL (600-1,400 mg/day), followed by the addition of boceprevir (800 mg three times a day).

The abstracts were published today and can be accessed on the AASLD website. For program information, please visit www.aasld.org.

Boceprevir Oral Presentations

HCV SPRINT-2 Final Results (Late-Breaking Oral Session)

Boceprevir (BOC) Combined with Peginterferon alfa-2b/Ribavirin (P/R) for Treatment-Naïve Patients with Hepatitis C Virus (HCV) Genotype (G) 1: SPRINT-2 Final Results; F. Poordad et al. Abstract LB-4. Monday, Nov. 1, 5:30 - 5:45 PM, Location: Hynes Auditorium

HCV RESPOND-2 Final Results (Viral Hepatitis Plenary Session)

HCV RESPOND-2 Final Results: High Sustained Virologic Response Among Genotype 1 Previous Non-Responders and Relapsers to Peginterferon/Ribavirin when Re-Treated with Boceprevir Plus PEGINTRON (Peginterferon alfa-2b)/Ribavirin; B. R. Bacon et al. Abstract 216. Tuesday, Nov. 2, 9:15 - 9:30 AM, Location: Hynes Auditorium

Boceprevir Poster Presentations

HCV SPRINT-2 (Late-Breaking Poster Session)

Response-Guided Therapy (RGT) with Boceprevir (BOC) + Peginterferon alfa-2b/Ribavirin (P/R) for Treatment-Naïve Patients with Hepatitis C Virus (HCV) Genotype (G) 1 Was Similar to a 48-Wk Fixed-Duration Regimen with BOC + P/R in SPRINT-2; J. Bronowicki et al. Abstract LB-15. Monday, Nov. 1, 8:00 AM - 5:00 PM, Location: Hynes Exhibit Hall C

HCV SPRINT-1 Phase II Data

Hemoglobin Decline During Lead-In Phase as an Early Predictor of Anemia After the Addition of Boceprevir: A Retrospective Analysis of HCV SPRINT-1; F. Poordad et al. Abstract 933. Sunday, Oct. 31, 8:00 AM - 5:30 PM, Location: Hynes Exhibit Hall C

Frequencies of Resistance-Associated Amino Acid Variants Following Combination Treatment with Boceprevir Plus PEGINTRON (PegInterferon Alfa-2b)/Ribavirin in Patients With Chronic Hepatitis C (CHC), Genotype 1 (G1); J. M. Vierling et al. Abstract 801. Sunday, Oct. 31, 8:00 AM - 5:30 PM, Location: Hynes Exhibit Hall C

Other Key Merck Data

High Correlation Between Week 4 and Week 12 as the Definition for Null Response to Peginterferon alfa (PEG) plus Ribavirin (R) Therapy: Results from the IDEAL Trial; F. Poordad et al. Abstract 797. Sunday, Oct. 31, 8:00 AM - 5:30 PM, Location: Hynes Exhibit Hall C