Is anybody home? That’s what people with multidrug-resistant HIV and no treatment options are yelling as they peer into the drug pipeline. For now, the answer is “Maybe.” First up in this effort is the fusion inhibitor T-20 (pentafuside) from Trimeris. The drug prevents the virus from fusing with its target cells by attaching to the gp41 protein on the virus’ surface, keeping it from coming close enough to bind to CD4 cells. In the latest study of 78 heavily pretreated PWAs, the average viral load decrease for those given 200 mg daily was 1.6 log, close to a protease inhibitor level of potency. Alas, even though the drug was added to current regimens, all that prior drug use meant the T-20 was probably acting almost alone—so viral resurgence occurred within a few weeks. This suggests that, as with all other antiretrovirals, T-20 must be taken with effective partners for long-term effectiveness—bad news for those with few or no drug options. Another problem: Two hefty injections of T-20 must be given both a.m. and p.m., equaling four potentially painful shots per day. Although some trial participants reported injection-site rashes and bumps during the 28-day trial, few complained. But over the long term, this drug-taking method may get under people’s skin.
T-20, Coming to a Combo Near You
May 1, 1999 • By Lark Lands, PhD