UPDATE 2-Pfizer HIV drug seems safe for new use-FDA staff

* FDA document says Selzentry “well tolerated”

* FDA advisory panel to meet Thursday

* Company: more HIV drugs needed (Adds company comment, background on drug, byline)

WASHINGTON, Oct 6 (Reuters) - Pfizer Inc's PFE.N HIV drug Selzentry appears to be safe for wider use in certain patients with the disease who have not yet begun taking any medications, U.S. Food and Drug Administration staff said in a document released on Tuesday.

The drug, also know by its generic name maraviroc, is already FDA-approved in combination with similar drugs for HIV patients who have tried other antiretroviral medications.

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

An FDA staff document said the drug appeared to be “well tolerated” in patients in a company-funded study. A review of an FDA database also found no new reported safety concerns in HIV patients who have already been taking the drug.

The agency's analysis of how well Selzentry worked also backed the company's findings that the drug reduced the virus in patients taking it, compared with those given efavirenz, the FDA said. Efavirenz is marketed as Sustiva by Bristol-Myers Squibb Co BMY.N.

The FDA released the document ahead of a public meeting on Thursday when the agency will ask its outside advisers for a recommendation on whether to approve the drug’s wider use. It usually follows their advice.

Pfizer said its trial showed the drug is safe and effective. As many HIV medications as possible are needed on the U.S. market now that the disease has transformed into more of a chronic condition, it added.

“Although there are other good treatment options available for patients, more are needed to meet the needs of a heterogeneous patient population,” the drugmaker said in a separate document also released on Tuesday.

If approved, Selzentry would only be indicated for adults with chemokine (c-c motif) receptor 5, or CCR5, tropic HIV-1, the FDA said. The drug aims to prevent the virus strain from entering the body’s cells, it added.

The documents were posted on the FDA's websitehere (Reporting by Susan Heavey, editing by Gerald E. McCormick and Maureen Bavdek)