March 9, 2012
Gilead Sciences Inc.'s experimental pill combining four HIV drugs has fewer side effects than the firm's current three-drug Atripla pill, according to data presented Wednesday in Seattle at the 19th Conference on Retroviruses and Opportunistic Infections. The Quad pill works as well as Atripla in controlling HIV, Gilead reported last year.
Patients on Atripla, which combines Gilead's Truvada (emtricitabine/tenofovir) with Bristol-Myers Squibb's Sustiva (efavirenz), had significantly higher rates of dizziness, abnormal dreams, insomnia, and rash compared with patients taking the Quad pill. However, Quad patients did report higher rates of nausea (21 percent vs. 14 percent). Quad consists of the experimental integrase inhibitor elvitegravir and boosting agent cobicistat combined with Truvada, all of which belong to Gilead.
At 48 weeks, 88 percent of Quad patients and 84 percent of Atripla patients had achieved the targeted levels of HIV. Discontinuation rates were similar: 1.4 percent dropped out of the Quad arm for kidney-related abnormalities, while 1.4 percent of Atripla patients discontinued due to rash. Participants taking Quad had a median serum creatinine increase -- a marker for kidney toxicity -- of 0.14 mg/dL, below the 0.4 mg/dL level that would have been a safety concern, said study leader Dr. Paul Sax, clinical director of infectious diseases at Brigham and Women's Hospital in Boston.
Quad is under regulatory review, and the Food and Drug Administration is due to decide by Aug. 27 whether to approve it.