Study supports
ongoing development of experimental HIV maturation
inhibitor

Study data presented this week at the Third International AIDS Society Conference on HIV Pathogenesis and Treatment in Rio de Janeiro shows that the experimental maturation inhibitor PA-457, under development by Vitex and the University of Buffalo, may be useful in controlling HIV infection, particularly in patients who've developed resistance to other anti-HIV medications. A Phase I/II study of the drug evaluated the effects of a single dose given to HIV-positive people currently not taking any other anti-HIV medications. After only one dose, study subjects showed a marked decrease in blood-based HIV viral loads. Two study subjects who had previously taken anti-HIV drugs and developed resistance to them also responded well to the experimental medication, researchers report.

A Phase IIa clinical trial is currently under way, and study data will be presented at the 45th ICAAC conference held in August in New Orleans, Vitex officials say.

Maturation inhibitors aim to interfere with the final stages of HIV replication in which viral copies are assembled and exit an infected cell. These experimental drugs aim to prevent the virus from properly assembling, from forming a protective outer coat, or from emerging--also known as budding--from human cells. There are currently no approved drugs that target this step in HIV's replication cycle. PA-457 specifically aims to interfere with assembly of HIV's capsid protein, which results in the manufacture of noninfectious copies of the virus.