Pfizer's Lyrica falls short in two pain studies

People walk past the Pfizer World headquaters in New York, February 3, 2010.

(Reuters) - Pfizer Inc's big-selling Lyrica drug failed to help HIV patients and diabetics relieve forms of nerve pain, according to separate clinical trial results released by the drugmaker on Friday.

Pfizer said it stopped a late-stage study involving patients with HIV neuropathy, a form of nerve damage characterized by burning pain. An interim look at the data by independent advisers overseeing the study prompted Pfizer to halt the study.

Lyrica did no better than a placebo in relieving the pain, according to the interim analysis. No safety concerns were raised by the advisers, Pfizer said.

A second late-stage study tested Lyrica for patients with painful diabetic peripheral neuropathy, which is a form of nerve damage characterized by burning or shooting pain in hands and feet. About 20 percent of diabetics suffer pain resulting from nerve damage, Pfizer said.

Lyrica did not meet the main effectiveness goal of the second study.

The results appear to cut off new growth avenues for Lyrica, which is approved to treat other forms of pain as well as seizures suffered by epileptics. Lyrica sales rose 16 percent to $955 million in the first-quarter results reported by Pfizer earlier this week.

(Reporting By Lewis Krauskopf; Editing by Gerald E. McCormick)