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BARCELONA, Spain--([ BUSINESS WIRE ])--MSD (NYSE: MRK), known as Merck in the United States and Canada, announced final results from a Phase III, open-label study designed to compare the impact of two anaemia management strategies on sustained virologic response (SVR)¹ in patients with chronic hepatitis C virus (HCV) genotype 1 infection treated with VICTRELIS (boceprevir) in combination with PEGINTRON (known as VIRAFERONPEG in some countries) (peginterferon alfa-2b) and ribavirin (P/R). The rates of SVR were 71 percent for both groups: those patients whose anaemia was managed by ribavirin dose reduction (178/249) and those patients whose anaemia was managed by the addition of erythropoietin (EPO) (178/251). The rates of relapse were identical at 10 percent in both groups. These results were presented today for the first time as part of a late breaker poster session [poster #1419] at The International Liver Congressa" / 47th European Association for the Study of the Liver (EASL) annual meeting.

"The results of this study show there was no difference in SVR rates among these anaemia management strategies and that ribavirin dose reduction should be the primary strategy for managing anaemia in patients taking boceprevir combination therapy."

"Chronic hepatitis C treatment regimens with peginterferon alfa and ribavirin are commonly associated with the development of anaemia, and this effect is further increased with the addition of boceprevir,a said Fred Poordad, M.D., chief of hepatology and liver transplantation, Cedars-Sinai Medical Center, Los Angeles. "The results of this study show there was no difference in SVR rates among these anaemia management strategies and that ribavirin dose reduction should be the primary strategy for managing anaemia in patients taking boceprevir combination therapy.a

About the Study

In this study, 687 treatment-nave adult patients with chronic HCV genotype 1 who had baseline hemoglobin levels of less than or equal to 15 g/dL were enrolled in a multinational, open-label trial and monitored for the development of anaemia. Patients were treated with a 4-week lead-in of peginterferon alfa-2b (1.5 mcg/kg/week) and an investigational dose of ribavirin (600-1,400 mg/day), followed by the addition of boceprevir (800 mg three times a day) after week 4 for 24 or 44 weeks based on HCV-RNA levels at treatment week 8. Sixteen (16) percent (111/687) of patients were enrolled in Cohort 1 and assigned a fixed-dose regimen that included the 4-week lead-in of P/R followed by the addition of boceprevir for 44 weeks. A protocol amendment was then added to allow the use of the response-guided therapy (RGT) paradigm, consistent with findings in the pivotal clinical studies for boceprevir, and the rest of the patients were enrolled in Cohort 2. The results for patients receiving the fixed-dose regimen (Cohort 1) versus the RGT paradigm (Cohort 2) did not differ and have been combined in the presentation of these data. Patients with a less than 2-log₁₀ decline in HCV-RNA at week 12, or a greater than or equal to lower limit of quantification of HCV-RNA at week 24 were considered treatment failures and were discontinued from the studies.

A total of 500 patients developed anaemia, defined by having hemoglobin of less than or equal to 10 g/dL (or less than 11 g/dL and were expected to reach less than or equal to 10 g/dL before the next visit). These patients were randomized to receive either ribavirin dose reduction (by 200 to 400 mg/d) or the addition of EPO (40,000 IU/week). A secondary method of anaemia management, such as the addition of EPO, ribavirin dose reduction or transfusion, was later permitted if a patient's hemoglobin reached less than or equal to 8.5 g/dL. Treatment was discontinued if hemoglobin levels reached less than or equal to 7.5 g/dL. If the initial hemoglobin measurement qualifying a patient as anaemic was less than or equal to 8.5 g/dL, that patient was not randomized to one of the anaemia management strategies.

The primary endpoint of the study was the comparison of SVR in patients who were randomized to receive ribavirin dose reduction or the addition of EPO.

Safety Findings

The safety profiles were similar regardless of anaemia management strategy. The most common adverse events (occurring in 30 percent or more of patients in either group) were anaemia, neutropenia, diarrhea, dysgeusia, nausea, chills, fatigue, headache, insomnia and alopecia. There was no difference in the incidence of adverse events between the ribavirin dose reduction and EPO treatment arms, including influenza-like symptoms (27 percent each), fatigue (70 percent vs. 71 percent), depression (20 percent vs. 21 percent), anxiety (12 percent each), shortness of breath (19 percent vs. 21 percent) and cardiovascular events (14 percent vs. 13 percent), respectively.

Serious adverse events occurred in 16 percent of patients in the ribavirin dose reduction arm and 13 percent of patients in the EPO arm. The discontinuation rates were 11 and 13 percent, due to any adverse event, and 2.0 and 2.4 percent due to anaemia, respectively. There was one death in the ribavirin dose reduction arm that occurred three weeks following the end of treatment, with cause of death reported as "sudden cardiac deatha.

About boceprevir

Boceprevir is indicated for the treatment of chronic hepatitis C (CHC) genotype 1 infection, in combination with peginterferon alfa and ribavirin, in adult patients with compensated liver disease who are previously untreated or who have failed previous therapy.

MSDas global commitment to advancing hepatitis therapy

MSD is committed to building on its strong legacy in the field of viral hepatitis by continuing to discover, develop and deliver vaccines and medicines to help prevent and treat viral hepatitis. In hepatitis C, company researchers developed the first approved therapy for chronic HCV in 1991 and the first combination therapy in 1998. In addition to ongoing studies with boceprevir, extensive research efforts are underway to develop additional innovative oral therapies for viral hepatitis treatment.

About MSD

Today's MSD is a global healthcare leader working to help the world be well. MSD is a tradename of Merck & Co., Inc., with headquarters in Whitehouse Station, N.J., U.S.A. Through our prescription medicines, vaccines, biologic therapies, and consumer care and animal health products, we work with customers and operate in more than 140 countries to deliver innovative health solutions. We also demonstrate our commitment to increasing access to healthcare through far-reaching policies, programs and partnerships. For more information, visit [ www.merck.com ] and connect with us on Twitter, Facebook and YouTube.

Forward-Looking Statement

This news release includes aforward-looking statementsa within the meaning of the safe harbor provisions of the United States Private Securities Litigation Reform Act of 1995. Such statements may include, but are not limited to, statements about the benefits of the merger between Merck and Schering-Plough, including future financial and operating results, the combined companyas plans, objectives, expectations and intentions and other statements that are not historical facts. Such statements are based upon the current beliefs and expectations of Merckas management and are subject to significant risks and uncertainties. Actual results may differ from those set forth in the forward-looking statements.

The following factors, among others, could cause actual results to differ from those set forth in the forward-looking statements: the possibility that all of the expected synergies from the merger of Merck and Schering-Plough will not be realized, or will not be realized within the expected time period; the impact of pharmaceutical industry regulation and health care legislation in the United States and internationally; Merckas ability to accurately predict future market conditions; dependence on the effectiveness of Merckas patents and other protections for innovative products; and the exposure to litigation and/or regulatory actions.

Merck undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events or otherwise. Additional factors that could cause results to differ materially from those described in the forward-looking statements can be found in Merckas 2011 Annual Report on Form 10-K and the companyas other filings with the Securities and Exchange Commission (SEC) available at the SECas Internet site ([ www.sec.gov ]).

¹ SVR, the protocol specified primary efficacy endpoint of the study, is defined as achievement of undetectable HCV-RNA at 24 weeks after the end of treatment in all randomized patients treated with any study medication. Per protocol, if a patient did not have a 24-week post-treatment assessment, the patientas 12-week post-treatment assessment was utilized.

VICTRELIS,PEGINTRON andVIRAFERONPEG aretrademarks of Schering Corp., a subsidiary of Merck &Co., Inc., Whitehouse Station, N.J., USA.
INFC-1029581-0005