FDA Approves Once-Daily Rilpivirine for HIV Infection

Emily Paulsen

 The US Food and Drug Administration (FDA) announced today the approval of once-daily rilpivirine (Edurant, Tibotec Therapeutics, a division of Centocor Ortho Biotech Inc) for treatment of HIV infection. Rilpivirine is a nonnucleoside reverse transcriptase inhibitor (NNRTI) that may be taken once daily in combination with other antiretroviral drugs for HIV-infected, treatment-naive patients.
"Patients may respond differently to various HIV drugs or experience varied side effects. FDA's approval of Edurant provides an additional treatment option for patients who are starting HIV therapy," said Edward Cox, MD, MPH, director of the Office of Antimicrobial Products in the FDA's Center for Drug Evaluation and Research.
The new drug gives clinicians an alternative to efavirenz, which has been considered the "gold standard" NNRTI — no other NNRTI has matched its efficacy since its approval in 1998. However, last summer, 2 phase 3 clinical trials of 1368 patients comparing rilpivirine with efavirenz revealed similar success rates: 83% of patients taking rilpivirine and 80% of patients taking efavirenz had undetectable amounts viral loads after 48 weeks of treatment. Each study enrolled about 700 patients.
In the studies, rilpivirine was associated with fewer adverse effects (especially central nervous system effects) and less lipid elevation. However, patients taking rilpivirine were more likely to experience virologic failure. Furthermore, virologic failure with rilpivirine resulted in cross-resistance to etravirine, eliminating that drug from future regimens. Patients with higher viral load at start of treatment were more likely not to respond to rilpivirine.
Paul Sax, MD, clinical director, Division of Infectious Diseases and HIV Program at Brigham and Women's Hospital, Boston, Massachusetts, explains: "The results of the study demonstrated that [rilpivirine] was better tolerated than efavirenz overall, but somewhat less effective in patients who entered the study with viral loads more than 100,000; as a result, there is a trade-off in this high-viral-load population between tolerability and virologic efficacy."
Still, for many patients, the low adverse effect profile reduces a significant barrier to achieving optimal adherence to antiretroviral therapy, Jose Zuniga, MD, president of the International Association of Physicians in AIDS Care, told Medscape Medical News. "The approval of the second-generation NNRTI rilpivirine is welcome news, specifically because of its potency and reduced side effect profile — both of which will help greater numbers of treatment-naive patients achieve and sustain viral suppression," he says.
According to Dr. Sax, a single-pill, once-daily coformulation of rilpivirine, tenofovir, and emtricitabine is currently in development.

courtesy: http://www.medscape.com/