FDA Panel Backs Theravance's MRSA Antibiotic

* NOVEMBER 19, 2008, 4:33 P.M. ET

FDA Panel Backs Theravance's MRSA Antibiotic

By JENNIFER CORBETT DOOREN
Wall Street Journal

WASHINGTON -- A federal advisory panel backed a proposed Theravance Inc. antibiotic designed to treat serious skin infections, including some caused by a type of staph bacterium known as MRSA that is resistant to many antibiotics.

The drug, telavancin, was considered Wednesday by a Food and Drug Administration panel of outside medical experts that was called to make recommendations to the agency about whether it thinks the drug should be approved.

The panel voted 21 to 5 in favor of a question asking whether the data presented demonstrated the safety and effectiveness of telavancin for the treatment of skin infections, which amounts to a recommendation the agency approve the drug. Such skin infections can be caused by MRSA, or methicillin-resistant staph aureus, as well as other types of bacteria. MRSA has sparked concern as the "superbug" has moved into community settings like schools and locker rooms in recent years after once being largely confined to hospital settings.

Several companies, including Theravance, based in South San Francisco, Calif., are developing drugs designed to treat the infections that often start with what appears to be a bug bite on the skin. Later Wednesday the same panel will consider Targanta Therapeutics Corp.'s oritavancin and will look at iclaprim by Swiss biotech company Arpida Ltd. Thursday.

The FDA said Theravance's telavancin worked as well as an older drug, vancomycin, in treating the skin infections when reviewing two main clinical studies conducted to examine telavancin. When looking at skin infections caused by just MRSA, the agency said Theravance appeared "numerically" better than vancomycin at treating the infection, but the difference didn't meet a statistical bar showing telavancin was superior.

The FDA said it was concerned that 3.4% of patients receiving telavancin had reported kidney problems compared to 1.2% of patients receiving vancomycin.

During the meeting, doctors who represented Theravance said that most kidney problems reversed after drug treatment was stopped and said the rates were similar to rates of kidney impairment seen among some patients being treated with other antibiotics.

Louis Saravolatz, the chairman of the department of medicine at St. John Hospital and Medical Center in Detroit, said the benefits of telavancin outweigh its risk.

He said current treatment of MRSA infections is limited to four drugs "that are associated with emerging resistance, toxicity or both."

Indeed, while many panel members said they were concerned about some of telavancin's side effects, they support FDA approval of the drug because more options are needed to combat serious skin infections.

"I voted yes because I think vancomycin is sort of a dying drug," said W. Kemper Alston, an associate professor of medicine at the University of Vermont in Burlington. He said doctors can easily detect any kidney problems if they use telavancin.

If approved by the FDA, telavancin would likely be sold under a risk-management plan designed to monitor the drug's safety after it reaches the market. The company has proposed creating a pregnancy registry to follow women and babies exposed to telavancin because of concerns about possible birth defects raised by animal studies of the drug.

Theravance has proposed selling telavancin as part of a controlled distribution system that would limit distribution to hospitals and home-health care agencies. The drug is an injection that needs to be administered once daily.

Write to Jennifer Corbett Dooren at jennifer.corbett-dooren@dowjones.com

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