Pfizer abandons
development of anti-HIV drug capravirine

Pfizer announced Friday that it is abandoning development of an experimental HIV therapy after two studies failed to show a significant difference between its capravirine drug and standard treatments for HIV. The pharmaceutical company said capravirine did not significantly boost the effectiveness of standard triple-drug anti-HIV therapies in two mid-stage trials of patients who had failed to respond to available antiretroviral therapies. Pfizer said it will return rights to the compound to its developer, Shionogi & Co. of Japan.