December 05, 2011
Gilead’s Boosting Agent, Cobicistat, Meets 48-Week Primary Objective in Pivotal Phase 3 Study
– Cobicistat is a Component of Company’s Quad Single-Tablet
Regimen, Currently Being Reviewed by U.S.
The Study 114 primary endpoint analysis indicated that after 48 weeks of treatment, 85 percent of patients taking a regimen of cobicistat-boosted atazanavir (a protease inhibitor) plus Truvada® (emtricitabine and tenofovir disoproxil fumarate) achieved HIV RNA (viral load) of less than 50 copies/mL, compared to 87 percent of patients taking ritonavir-boosted atazanavir plus Truvada (95 percent CI for the difference: -7.4 percent to 3.0 percent). The predefined criterion for non-inferiority was a lower bound of a two-sided 95 percent CI of -12 percent. Discontinuation rates due to adverse events were 7.3 percent and 7.2 percent in the cobicistat and ritonavir arms of the study, respectively. Gilead plans to submit these data for presentation to a scientific conference in 2012.
“The majority of today’s protease-based HIV treatment regimens depend on
a boosting agent for optimal efficacy,” said
Small increases in serum creatinine (a value used to estimate kidney function) with resulting decreases in estimated creatinine clearance (by Cockroft-Gault) were observed in this study. At 48 weeks, the mean increase from baseline in serum creatinine was 0.14 mg/dL among cobicistat patients and 0.09 mg/dL among ritonavir patients. The increase in serum creatinine with cobicistat occurs within days of drug initiation and is reversible with values returning to baseline within days after cessation of cobicistat. Results from a separate Phase 1 renal study in healthy volunteers indicate that cobicistat does not affect actual glomerular filtration rates (GFR) as assessed by iohexol clearance (a true measure of kidney function).
About the Cobicistat Phase 3 Study
Study 114 is a randomized, double-blind, Phase 3 clinical trial
comparing the efficacy and safety of cobicistat-boosted atazanavir
versus ritonavir-boosted atazanavir, each administered with Truvada,
over a 96-week period at more than 200 study sites in
The primary endpoint of the study was the proportion of patients
achieving HIV RNA levels of less than 50 copies/mL at 48 weeks of
treatment, as determined by the
Cobicistat is Gilead’s proprietary potent mechanism-based inhibitor of cytochrome P450 3A (CYP3A), an enzyme that metabolizes drugs in the body. Cobicistat is an investigational product and its safety and efficacy have not yet been established.
This press release includes forward-looking statements, within the
meaning of the Private Securities Litigation Reform Act of 1995, that
are subject to risks, uncertainties and other factors, including risks
related to Gilead's plans to present the data at a scientific conference
and file for regulatory approval of cobicistat in the timelines
currently anticipated and the possibility of unfavorable results from
further clinical studies of cobicistat. Further, Gilead may fail to
obtain approvals from regulatory authorities and any marketing approval,
if granted, may have significant limitations on its use. As a result,
cobicistat may never be successfully commercialized. In addition, Gilead
may make a strategic decision to discontinue development of cobicistat
if, for example, it believes commercialization will be difficult
relative to other opportunities in its pipeline. These risks,
uncertainties and other factors could cause actual results to differ
materially from those referred to in the forward-looking statements. The
reader is cautioned not to rely on these forward-looking statements.
These and other risks are described in detail in Gilead’s Quarterly
Report on Form 10-Q for the quarter ended
U.S. full prescribing information for Truvada is available at www.Truvada.com.
Truvada is a registered trademark of
For more information on
Gilead Sciences, Inc.
Susan Hubbard, 650-522-5715 (Investors)
Erin Rau, 650-522-5635 (Media)