Data from Merck’s Investigational Hepatitis C Treatment Portfolio to be Presented at the 64th American Association for the

  Data from Merck’s Investigational Hepatitis C Treatment Portfolio to be
  Presented at the 64th American Association for the Study of Liver Diseases
  Annual Meeting

Business Wire

WHITEHOUSE STATION, N.J. -- October 1, 2013

Merck (NYSE:MRK), known as MSD outside the United States and Canada, today
announced the presentation of data from studies evaluating the company’s
investigational oral chronic hepatitis C virus (HCV) treatments MK-5172 and
MK-8742 at the 64^th American Association for the Study of Liver Diseases
Annual Meeting (AASLD). The meeting is scheduled to take place in Washington,
D.C., Nov. 1-5, 2013.

“Merck is committed to developing HCV therapies that have the potential to
offer new options for a broad range of patient types,” said Dr. Eliav Barr,
vice president, Infectious Diseases, Merck Research Laboratories. “We continue
to build upon our strong legacy in HCV and look forward to sharing the latest
clinical data for our investigational HCV therapies, MK-5172 and MK-8742.”

MK-5172 is an investigational, once-daily, oral HCV NS3/4A protease inhibitor
currently in Phase IIB development. MK-8742 is an investigational, once-daily,
oral HCV NS5A replication complex inhibitor currently in Phase IIB
development. Both candidates are being evaluated in broad clinical programs
that include investigations in various HCV segments, multiple HCV genotypes
and patients who have previously failed prior therapy.

Selected presentations of clinical data for MK-5172 and MK-8742

  *High Efficacy and Safety of the All-Oral Combination Regimen,
    MK-5172/MK-8742 +/- RBV for 12 Weeks in HCV Genotype 1 Infected Patients:
    The C-WORTHY Study. Lawitz, E., et al. Oral Presentation #76: Sunday, Nov.
    3, 2013, 5:30-5:45 p.m.
  *Kinetic Analyses of Antiviral Suppression by NS5A Inhibitors Reveal Early
    and Potent Inhibition of Viral Assembly and Release. McGivern, D.R., et
    al. Oral Presentation #78: Sunday, Nov. 3, 2013, 6:00-6:15 p.m.
  *High Efficacy at Lower Doses of MK-5172 25mg and 50mg Daily for 12 weeks
    in HCV Genotype (G) 1 Treatment-Naïve Non-Cirrhotic Patients. Vierling,
    J., N et al. Poster #1123. Sunday, Nov. 3, 2013, 8:00 a.m. to 5:30 p.m.
  *Efficacy and Safety of an Interferon-Free Regimen of MK-5172 + Ribavirin
    for 12 Weeks or 24 Weeks in Treatment-Naïve, Non-Cirrhotic Subjects with
    HCV GT1 Infection: The C-SPIRIT Study. Gane, E.J., et al., Poster #1110.
    Sunday, Nov. 3, 2013, 8:00 a.m. to 5:30 p.m.
  *MK-8742, a HCV NS5A Inhibitor with a Broad Spectrum of HCV Genotypic
    Activity, Demonstrates Potent Antiviral Activity in Genotype-1 and -3
    HCV-Infected Patients. Yeh, W. W., et al. Poster #479. Saturday, Nov. 2,
    2013, 2:00-7:30 p.m.

The abstracts were published today and can be accessed on the AASLD website.
For program information, please visit:
http://www.aasld.org/livermeeting/program/Pages/default.aspx

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