Progenics reports successful early-stage trial for HIV drug

Patients receiving a single 5mg/kg dose of PRO 140 achieved an average maximum decrease of viral concentrations in the blood of 98.5%, with individual reductions ranging up to 99.7%. In these patients, reductions in viral load of greater than 90% on average persisted for two to three weeks after dosing.

In addition, PRO 140 was generally well tolerated in this phase Ib proof-of-concept study. PRO 140 was granted Fast Track status from the FDA, and Progenics plans to initiate additional clinical testing in the second half of 2007.

PRO 140 is a humanized monoclonal antibody that binds CCR5, the principal portal used by HIV to enter cells. It is one of a new class of drugs which binds to the CCR5 receptor on healthy immune system cells, protecting them from infection, rather than targeting the virus itself. An FDA advisory committee has recently recommended an accelerated approval process for Pfizer’s CCR5 drug, maraviroc.