UPDATE 2-US FDA panel backs wider use of Pfizer HIV drug

* FDA panel votes 10-4 to OK wider Selzentry usage

* Some advisers express ‘ambivalence,’ ‘anxiety’ over drug (Adds details from panel, company comment, share price, byline)

WASHINGTON, Oct 8 (Reuters) - A U.S. Food and Drug Administration advisory panel on Thursday recommended Pfizer Inc's PFE.N HIV drug Selzentry be approved for wider use in certain patients with the disease, despite concern from several panel members that they were underwhelmed by the data.

Pfizer is seeking U.S. approval to market Selzentry for HIV patients who have a specific type of HIV-1 -- one of two strains of the human immunodeficiency virus that causes AIDS -- who have not tried any medications yet. It would be taken with other antiretroviral drugs.

In a 10-4 vote, panel members backed the wider use, saying it did offer doctors and patients another choice even if more data is needed.

“We’re not looking for the absolute best, we’re looking for an option,” said panelist Dr. Victoria Cargill, who heads minority research at the National Institutes of Health’s Office of AIDS Research, and voted for the drug.

FDA officials will weigh the panel’s vote before making its final approval decision. Pfizer said it expects a decision by Nov. 20.

Selzentry, also known as maraviroc, is already approved for use along with other drugs for HIV patients who have tried other antiretrovirals but have developed a resistance to them.

If approved, Selzentry would be expanded to adults with chemokine (c-c motif) receptor 5, or CCR5, tropic HIV-1 who have not yet begun treatment. Patients would need to first be tested for that particular strain before taking the medication, the company said.

But a number of panelists, even those who opted for the drug, said they were conflicted about backing the wider use given the company’s somewhat limited data.

Panelist Dr. Russell Van Dyke, professor at Tulane University School of Medicine, said he voted for the expanded use despite feeling some anxiety about it.

“I worry that it’s not quite as potent as we’d like it to be,” he said.

Pfizer officials said their trial, which compared Selzentry to efavirenz, showed its drug helped reduce viral load. Efavirenz is marketed as Sustiva by Bristol-Myers Squibb Co BMY.N.

But some panelists said that a number of other options have hit the U.S. market in recent years. Several panelists said the company’s data was underwhelming, especially given other available drugs.

They noted concerns about the number of patients in the study who stopped using the drug because of side effects like dizziness or rash as well as those who developed a resistance.

“We have several first-line options available to us in 2009. I’m not convinced that this drug is my first choice” for patients who are new to HIV medications, said Dr. Barbara McGovern, a professor of medicine at Tufts University School of Medicine who voted against the drug.

Overall, panelists said they wanted Pfizer to gather more data on the effect of the drug in pregnant women as well as patients with hepatitis or tuberculosis. They also urged FDA officials to make the drug’s limitations clear on its label.

While the FDA does not factor costs into its approval decisions, some consumer advocates after the panel’s vote called on Pfizer to lower the price of Selzentry, which it says has risen 10 percent since its initial approval in 2007 to $13,767 per patient for a year’s worth of treatment.

“While any new HIV/AIDS drug is welcome, we urge Pfizer to use restraint and to lower the price of Selzentry immediately,” said AIDS Healthcare Foundation President Michael Weinstein, whose nonprofit groups provides health care to HIV and AIDS patients around the world.

Some panelists also mentioned the drug’s cost. Pfizer reported $46 million in Selzentry sales in 2008.

In a statement, Pfizer said it was pleased with the panel’s vote and would work with the FDA on the drug’s label. Shares of the drugmaker closed up 1 cent to $16.70 on the New York Stock Exchange on Thursday. (Reporting by Susan Heavey; Editing Bernard Orr and Carol Bishopric)