Reuters (09.19.11) - Tuesday, September 20, 2011

Gilead Sciences Inc. announced on Monday that its investigational once-daily "Quad" tablet reduced HIV viral loads in treatment-naive trial participants as well as a regimen combining existing treatments. The Foster City, Calif.-based company plans to request Food and Drug Administration "priority review" by the end of this year, rather than the first quarter of next year as previously announced. Approval could be granted as early as mid-2012.

The Quad pill combines two experimental agents, the integrase inhibitor elvitegravir and the boosting agent cobicistat, with Truvada (emtricitabine/tenofovir). In this latest Phase III trial, Quad was compared with ritonavir-boosted atazanavir (Reyataz) plus Truvada.

At the end of 48 weeks, 90 percent of patients taking Quad achieved an HIV RNA viral load of less than 50 copies/mL, compared with 87 percent of participants on the control regimen. While 5.1 percent dropped out of the control group due to adverse events (primarily due to elevated bilirubin levels), just 3.1 percent of Quad participants did so.

"The 90 percent response rate observed on the Quad arm in this study is an unprecedented result and speaks to the potency, safety, and convenience of an integrase-based single-tablet regimen," said Norbert Bischofberger, PhD, Gilead's chief scientific officer.

"Overall the data are good ... mostly in line with investor expectations," said Cowen and Co. analyst Philip Nadeau. "I think there might have been a little bit of expectation for statistical superiority, but only from a few outliers."