Regulatory

Entecavir effective against hepatitis B

Last Updated: 2005-03-10 16:05:29 -0400 (Reuters Health)

By Susan Heavey

WASHINGTON (Reuters) - Bristol-Myers Squibb Co.'s. experimental drug entecavir is effective for the treatment of chronic hepatitis B infection, but Food and Drug Administration reviewers also expressed concern over possible long-term resistance to the drug and cancer risks.

The FDA released documents on Thursday, ahead of a panel meeting with outside experts on Friday to discuss whether the drug should be approved. The agency usually, but not always, takes its panelists' advice.

Clinical trials and related studies showed entecavir "effectively reduces the (hepatitis B) viral burden," the reviewers said.

Studies also showed a number of other benefits in patients taking the drug for 48 weeks, including few major interactions with other drugs and easily adjusted doses, they said.

But reviewers also expressed caution. "These positive findings...must be weighed against findings that are less clearly understood."

The effect of the drug beyond 48 weeks is not clear, they said, warning that there may be a possibility of resistance. "This may have a significant impact on long-term dosing as the clinical trials continue," they said.

The company's studies also left lingering questions over whether the medicine could cause cancer, the reviewers said. They called for the experts to discuss the risk on Friday.

"To our knowledge, there has not been a public discussion of an acceptable level of carcinogenicity risk in relationship to chronic HBV treatment," the reviewers wrote.

Novartis and Idenix Pharmaceuticals Inc. are jointly developing a rival hepatitis drug called telbivudine.