UPDATE 2-US panel backs Theratech drug for HIV patients

* Panel votes 16-0 to recommend approval of Egrifta

* FDA usually follows panel recommendations

* Final decision due by July 27 (Adds company, panelist, analyst comments)

By Lisa Richwine

ADELPHI, Md., May 27 (Reuters) - An experimental drug from Theratechnologies Inc (TH.TO) to reduce abdominal fat in HIV patients should be approved, a U.S. advisory panel unanimously said on Thursday.

The committee voted 16-0 to recommend Food and Drug Administration approval of the injectable drug, Egrifta. It would be the Canadian biotech company's first approved product if it reaches the market.

Panelists said the drug clearly was shown in two company studies to cut excess abdominal fat that can accumulate in people taking HIV medications, a bothersome side effect for many patients that has no approved treatment. The committee said that benefit could boost the well-being of patients who are distressed with the weight gain.

"If you can improve someone's outlook on life, I think that's very important," said panelist Michael Proschan, a statistician at the National Institutes of Health.

The FDA usually follows panel recommendations. A final ruling is due by July 27.

Montreal-based Theratechnologies has a U.S. licensing agreement with Merck KGaA's (MRCG.DE) EMD Serono division for Egrifta and stands to collect $215 million in milestone payments and royalties from Serono if the drug is approved.

The company's positive study results plus the panel's endorsement "greatly enhance the probability that FDA will approve Egrifta," said Douglas Loe, an analyst at Versant Partners. He projects royalties to Theratechnologies to peak at $192 million in 2017.

The drug, known generically as tesamorelin, was developed to reduce fat deposits that can build up in the abdominal cavity of patients taking HIV drugs. An estimated 200,000 to 800,000 HIV patients may have the condition, known as lipodystrophy, FDA staff said.

With Egrifta, patients inject the drug daily into the stomach. In company studies, people treated for a year lost about 18 percent of their abdominal fat. But they gained most of it back within about three months of stopping the drug, FDA reviewers said. That means patients likely will need to use Egrifta indefinitely to maintain its benefits.

The excess fat can raise the risk of heart disease. Members of the FDA panel said the company's data on Egrifta did not show that reducing the fat would cut the chances of cardiovascular harm. They urged post-approval studies to see if that was the case.

Panelists also suggested additional studies after approval plus close monitoring of patients for potential harm.

FDA reviewers noted an increase in diabetes with Egrifta compared with a placebo, and elevated levels of insulin-like growth factor, or IGF-1, in some patients. There are concerns high IGF-1 for an extended time may raise the risk of cancer or heart disease.

Panel members generally agreed the risk of diabetes was small and should not prevent approval as it is treatable. The committee also said the cancer risk was low.

Some suggested use of the drug be restricted to a few years, but others disagreed, saying there was no hard evidence of serious risks.

Theratechnologies Chief Executive Yves Rosconi said he was pleased with the panel's vote.

"We're happy. For a small little biotech to develop a drug for an unmet medical need this is quite an ... achievement," he said in an interview.

Theratechnologies shares were halted while the panel met. The shares had fallen sharply on Tuesday when FDA reviewers released a preliminary analysis that raised safety concerns. (Reporting by Lisa Richwine; Editing by Gary Hill and Steve Orlofsky)