Panel Backs Pfizer HIV Drug

A panel of outside medical advisers said Tuesday that the Food and Drug Administration should approve a Pfizer(PFE) HIV and AIDS drug to treat patients for whom other medications aren't effective.

The advisory committee unanimously endorsed maraviroc, a pill that Pfizer started developing in 1997. The FDA isn't bound by advisory panel recommendations, but the agency usually follows the suggestions. The FDA is scheduled to decide in June.

If approved, maraviroc would be the first in a new class of drugs called CCR5 antagonists, also known as CCR5 inhibitors. These drugs fight the AIDS-causing human immunodeficiency virus, or HIV, in a different manner than other medications. Maraviroc blocks HIV from entering cells through a pathway called a CCR5 coreceptor, one of two entry points for the virus.

Analysts predict maraviroc can be a solid but not spectacular contributor to corporate revenue. For example, Zacks Equity Research recently forecast worldwide sales could reach $490 million by 2011. Sagient Research Systems, an independent tracker of drug development, recently predicted that U.S. sales alone would be $403 million by 2011.

The advisory panel recommended that Pfizer conduct additional tests to assess side effects and the drug's effectiveness on a broader population than has been tested. In the company's clinical trials submitted to the FDA, 90% of the patients were male and 83% were Caucasian.

In late trading Tuesday, Pfizer's stock was off 15 cents to $26.22.

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