SB497115 (Oral Thrombopoietin Receptor Agonist) Versus Placebo In Adults With Thrombocytopenia Due To Hepatitis C

A Double-Blind, Randomized, Placebo-Controlled, Multi-Centre, Dose-Ranging, Parallel Group, Phase II Study to Assess Efficacy, Safety/Tolerability, and Pharmacokinetics of a Thrombopoietin Receptor Agonist, SB-497115-GR, When Administered as 30, 50, and 75 mg Once Daily for 12 Weeks in Subjects With

SB497115 is an oral agent which activates the thrombopoietin receptor and increases platelet counts in healthy volunteers. This study is examining several different doses of SB497115 as a treatment for patients with chronic hepatitis C-related thrombocytopenia who are potential candidates for antiviral treatment with pegylated interferon and ribavirin. The study will be conducted in two phases, Parts 1 and 2. In Part 1, study subjects will be randomized to 4 weeks of SB-497115-GR or placebo administered daily without antiviral therapy. Subjects who successfully complete Part 1 (platelet count 70,000/µL for Pegasys and platelet count 100,000/µL for PEG-Intron) will then proceed to Part 2. In Part 2, subjects will receive an additional 8 weeks of SB-497115-GR or placebo administered daily with antiviral therapy.

A Double-Blind, Randomized, Placebo-Controlled, Multi-Centre, Dose-Ranging, Parallel Group, Phase II Study to Assess Efficacy, Safety/Tolerability, and Pharmacokinetics of a Thrombopoietin Receptor Agonist, SB-497115-GR, when Administered as 30, 50, and 75 mg Once Daily for 12 weeks in Subjects with Chronic Hepatitis C-Related Thrombocytopenia who are Potential Candidates for Antiviral Treatment with Pegylated Interferon and Ribavirin.

Inclusion criteria:

• Chronic low platelet count between 20,000 and <70,000/µL.
• Prior liver biopsy indicating chronic hepatitis within the previous 5 years or radiographic evidence of cirrhosis and / or endoscopic evidence of non-bleeding esophageal or gastric varices.

Exclusion criteria:

• History of heart attack or abnormal heart function.
• History of thrombosis within 1 year.
• History of alcohol or drug abuse or dependence within 1 year.
• Use of aspirin, aspirin-containing compounds, salicylates, antacids.
• History of HIV infection or active infection with Hepatitis B or C.
• Females who are pregnant.
• Patients using non-steroidal anti-inflammatory drugs during the study and within 3 weeks prior to starting the study.