Is Gels� Success in Existing Med?

Research presented at the 17th Conference on Retroviruses and Opportunistic Infections indicates a new class of antiretroviral drugs called CCR5 entry inhibitors could be used to produce an effective microbicide against HIV. The drugs block HIV from entering human cells using a type of cellular doorway or receptor named CCR5.

John Moore of Weill Cornell Medical College and colleagues tested the CCR5 inhibitor maraviroc, a Pfizer drug sold under the brand name Selzentry. Tests in monkeys showed a candidate microbicide containing the drug would protect a female from sexual HIV transmission for about four hours.

Scientists have long been searching for a cream, gel, or vaginal ring that could provide a chemical shield against HIV, and several substances have been tested unsuccessfully. "The next wave of compounds is all going to be based on antiretroviral drugs," Moore said.

"The CCR5 inhibitors are compelling candidates as an alternative because these drugs are not being used for treatment in, for example, Africa," said Moore, meaning there is less risk of resistance developing.

The approach could also be affordable, Moore noted. A single 300 mg maraviroc tablet retails for about $15 online and contains enough drug to fully protect roughly 15 macaques, he said. "That is broadly going to be applicable to women."