A Multiple Dose Study to Evaluate Safety, Pharmacokinetics, and Pharmacodynamics of MK-8408 in Subjects with Hepatitis C Infection

MK-8408 is a HCV NS5a inhibitor for the potential treatment of HCV infection.
The purpose of this trial is to investigate safety, pharmacokinetics and
pharmacodynamics in HCV infected patients.

-To identify a safe dose of MK-8408 in HCV infected patients that mediates a
3Log10 reduction
-To evaluate safety and tolerability of MK-8408 administered for 5 consecutive
days
-To evaluate the plasma pharmacokinetic profile of multiple oral doses of
MK-8408 in HCV infected patients

This is a three-part, multiple panel, multi-site, open label trial of MK-8408
in subjects with Hepatitis C Virus (HCV) infection of genotype GT3 (Part I),
GT1a (Part II) and GT2b (Part III), to be conducted in conformance with Good
Clinical Practices.

The study will start with a screening visit. During the screening visit
standard medical assessments including safety laboratory tests (blood draw,
urine collection), an alcohol breath test, urine drug screen, a physical
examination, ECG and a vital signs measurement will be performed.

During the study the subjects will stay in the unit on certain days or return
to the unit to receive study medication on 5 subsequent days. After these 5
days of dosing, there are some visits to the site for blood collection and a
follow up visit. During all the visits (up to Day 61) and during the stays in
the unit, subjects will be asked on a regular base for possible side effects,
blood will be drawn for safety, PK and PD measurements and other standard
safety assessment (VS, ECG, lab safety tests,*) can be performed during these
days.

Single doses of MK-8408 have been generally safe and well-tolerated by the
subjects in the first study with MK-8408. No serious adverse experiences have
been reported and no subject has been discontinued by the Investigator.
Adverse experiences have been mild to
moderate in intensity and transient in duration. Twelve (12) subjects have
reported adverse experiences. Since the trial is still blinded, it is not known
if these adverse events were experienced by subjects receiving active drug or
placebo. The reported adverse experiences are headache (19), photophobia (1),
nausea (1), sore throat (1), and ecchymosis at the site of a blood draw (1).
There have been no consistent treatment-related changes in laboratory, vital
signs, or ECG safety parameters.