Lersivirine — A Promising New Nonnucleoside Reverse Transcriptase Inhibitor

Tenofovir/FTC/efavirenz is a potent and guideline-preferred treatment regimen. Use of efavirenz, however, is limited by its adverse event profile, its low barrier to resistance, its category D pregnancy rating, and its interaction with other drugs. Lersivirine — a next-generation nonnucleoside reverse transcriptase inhibitor (NNRTI) — has shown promise in early clinical trials, but its comparative efficacy has not been established.

In a manufacturer-sponsored, placebo-controlled, double-blind, phase IIb study, 195 HIV-infected adults with viral loads ≥1000 copies/mL and CD4 counts ≥200 cells/mm³ were randomized to receive tenofovir/FTC plus either lersivirine (500 or 750 mg once daily) or efavirenz (600 mg once daily). In a modified intent-t…