Pharmasset Voluntarily Halts Clinical Studies with Clevudine in Hepatitis B Infecte...( - Company will increase focus on HCV ...),Health

- Company will increase focus on HCV pipeline

- Conference call at 8:00 AM ET today

PRINCETON, N.J., April 20 /PRNewswire-FirstCall/ -- Pharmasset, Inc. (Nasdaq: VRUS) announced today that after a discussion with its independent Data Safety Monitoring Board (DSMB) and the FDA, the company has decided to voluntarily terminate its Phase III QUASH studies of clevudine for the treatment of chronic hepatitis B (HBV) infection.

Pharmasset recently became aware of a number of spontaneous Serious Adverse Event reports and Events of Special Interest in patients receiving clevudine as prescribed therapy for hepatitis B in South Korea. Though only a small number of cases of mild to moderate myopathy, or muscle weakness associated with creatine kinase elevations, were reported in the QUASH studies, many of the patients in South Korea have had longer exposures to clevudine than patients in the QUASH studies and have reported more serious myopathy than have patients in the Pharmasset clinical trials. Given the number and severity of cases observed in South Korea, Pharmasset concluded it was in the best interest of patients to terminate the studies at this time.

"The safety of patients in the QUASH studies is our top priority and, therefore, we have decided to stop treatment with clevudine," stated Michelle Berrey, MD, MPH, Pharmasset's Chief Medical Officer. "Although the number of cases of myopathy in the QUASH trials was low and the severity was mild, more severe reports from other trials and post marketing surveillance led us to believe the risk benefit ratio for clevudine was insufficient to continue development. We would like to take this opportunity to thank patients and our investigators for their participation in the QUASH studies."

As part of the study shut down, Pharmasset plans
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