DRUG DEVELOPMENT

Better Together

Pharmasset inks collaboration with Tibotec on hepatitis C combination therapy.

MICHAEL FITZHUGH

The Burrill Report

“Fewer than half of patients infected with genotype 1 HCV are cured using the interferon/ ribavirin combination after a first course of therapy.”

Pharmasset has entered a mid-stage clinical collaboration with Tibotec Pharmaceuticals to evaluate a combination of the companies’ chronic hepatitis C drugs that could eventually form the basis of a treatment free from the unpleasant side effects associated with current regimens for battling the virus.

Hepatitis C is the most common chronic blood-borne infection in the United States, where about 3.2 million persons are chronically infected. More than 170 million people are thought to be infected with the virus worldwide.

The standard therapy involves injection of pegylated interferon and ribavirin, but patients often suffer side effects from the interferon, including headaches, fever, fatigue, loss of appetite, and other maladies during the course of treatment. Fewer than half of patients infected with genotype 1 HCV are cured using the interferon/ribavirin combination after a first course of therapy.

Pharmasset and Tibotec’s mid-stage proof of concept study will evaluate the potential of the combination of the investigative drugs PSI-7977 and TMC435 to eliminate detectable levels of the virus after 12 weeks of treatment with an all oral, once-daily, interferon-free treatment regimen in patients infected with the genotype 1 form of hepatitis C, the most common genotype found in the United States. The partners plan to start the study in the second half of this year.

Financial terms of the agreement were not disclosed.

“We are excited to be working with Tibotec to simplify and improve HCV treatment,” says Bill Symonds, Pharmasset's SVP of clinical pharmacology and translational medicine. “This advances one of our key goals at Pharmasset: to develop our nucleotide analogs as the backbone of interferon-free HCV therapy.”

Once the joint study with Tibotec begins, PSI-7977 will be in testing as an interferon-free combination with not just Tibotec’s protease inhibitor, but also Bristol-Myers Squibb's NS5a inhibitor, and another Pharmasset nucleotide, PSI-938.

The Pharmasset deal is the second collaboration recently announced by Tibotec, a unit of Johnson & Johnson’s Janssen Pharmaceuticals, to evaluate a combination therapy. In June, Gilead said it would license Tibotec’s protease inhibitor Prezista in order to develop a new once-daily formulation of the HIV medicine.

Tibotec is also still working to develop telaprevir, which was approved as Incivek for the treatment of hepatitis C by the U.S. Food and Drug Administration in May.

Burrill & Company, publisher of The Burrill Report, is an investor in Pharmasset.












July 08, 2011
http://www.burrillreport.com/article-better_together.html