Gilead submits New Drug Application to U.S. FDA for boosting agent cobicistat

Gilead Sciences, Inc. (Nasdaq: GILD) announced today it has submitted a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) for marketing approval of cobicistat, a pharmacoenhancing or “boosting” agent that increases blood levels of certain commercially available protease inhibitors, including atazanavir and darunavir, in order to enable once-daily dosing. Cobicistat is also a component of the Quad once-daily single tablet regimen for HIV, which is currently under U.S. and European regulatory review for treatment-naïve adult patients.

“With today’s filing, Gilead’s series of U.S. and European regulatory filings for the Quad and its investigational components is complete,” said Norbert Bischofberger, PhD, Executive Vice President, Research and Development and Chief Scientific Officer, Gilead Sciences. “We will continue to work with regulatory authorities to bring these important new therapies to people living with HIV.”

The NDA for cobicistat is supported by 48-week data from a pivotal Phase 3 study (Study 114) in which cobicistat met its primary objective of non-inferiority to ritonavir when both agents were administered with a background regimen of atazanavir sulfate plus Truvada®(emtricitabine and tenofovir disoproxil fumarate). The NDA is also supported by pharmacokinetic data demonstrating that cobicistat boosts blood levels of atazanavir and darunavir similar to ritonavir.

Gilead entered into an agreement with Janssen R&D Ireland in June 2011 for the development of a fixed-dose combination of cobicistat and darunavir. In October 2011, Gilead announced an agreement with Bristol-Myers Squibb to develop a fixed-dose combination of cobicistat and atazanavir. Subject to regulatory approval, Janssen and Bristol-Myers Squibb will be responsible for the formulation, manufacturing, registration, distribution and worldwide commercialization of the cobicistat and darunavir fixed-dose combination and the cobicistat and atazanavir fixed-dose combination, respectively.

About Cobicistat

Cobicistat is Gilead’s proprietary potent mechanism-based inhibitor of cytochrome P450 3A (CYP3A), an enzyme that metabolizes drugs in the body. Unlike ritonavir, cobicistat acts only as a pharmacoenhancer and has no antiviral activity.

About the Quad

The Quad contains four Gilead compounds in a complete once-daily, single tablet regimen: elvitegravir 150 mg, an integrase inhibitor; cobicistat 150 mg, a “boosting” agent that enables elvitegravir once-daily dosing; and Truvada (emtricitabine 200 mg/tenofovir disoproxil fumarate 300 mg).

Cobicistat, elvitegravir and the Quad are investigational products and their safety and efficacy have not yet been established.