Gilead Sciences has officially announced the start of a new Phase 3 clinical trial program investigating the fixed dose, single tablet “Quad” regimen.

The “Quad” regimen includes elvitegravir, cobicistat (GS 9350), Emtriva (emtricitabine), and Viread (tenofovir). Quad therapy combines different drugs into a single pill, which makes adherence to a therapeutic regimen easier for HIV patients.

“Efficacy and safety results from the Phase 2 study suggest that the Quad may represent an important new option for patients with HIV,” said Dr. Norbert Bischofberger, Executive Vice President of Research and Development and Chief Scientific Officer of Gilead Sciences in a press release.

Since efficacy and safety results from previous Phase 2 trials have indicated that the Quad may be useful to HIV patients, further studies into the clinical effectiveness of the drug have been authorized (see related Beacon news).

The Phase 3 trials are split into two studies: one study examines the efficacy, safety, and tolerability of Quad versus Atripla (efavirenz/emtricitabine/tenofovir). The second study compares the efficacy, safety, and tolerability of Quad to Reyataz (atazanavir) and Truvada (emtricitabine/tenofovir).

Both studies will be conducted over a 96-week period among patients who have never received anti-HIV therapy).

Meanwhile, the United States Food and Drug Administration (FDA) reprimanded Gilead for false advertising regarding Truvada.

In a recent letter to the Director of Regulatory Affairs at Gilead Sciences, the FDA pointed out several misleading and false statements in a direct-to-consumer print advertisement for Truvada. According to the FDA, the ad exaggerates the efficacy of Truvada and minimizes associated health risks.

In overstating Truvada’s efficacy, the print ad suggests that taking Truvada will allow patients to maintain undetectable HIV viral loads on a long-term basis. The letter from the FDA points out that this claim has not been substantiated by clinical data.

Currently, clinical trials show that Truvada was proven effective over a three-year study, which does not correspond to the long-term claims implied by the print advertisement.

The FDA also claims that Gilead minimizes the risks associated with Truvada by emphasizing the beneficial aspects of the drug in an aesthetically appealing way, while mentioning the harmful risks in small print towards one side of the advertisement. This was deemed as potentially misleading to advertisement readers.

Due to these violations, the FDA has requested that Gilead discontinue the use of advertisement materials that are in conflict with official regulations.

For more information regarding the clinical trial and the FDA warning, please see the Gilead and FDA (pdf) websites.