January 24, 2012
Gilead Initiates Phase 2 Clinical Trial Evaluating GS-7340, A Low-Dose Novel Prodrug of Tenofovir for the Treatment of HIV
– Phase 2 Study Will Examine GS-7340 as Part of a
“The advancement of GS-7340 into this Phase 2 study is an important
milestone in Gilead’s efforts to develop the next generation of
best-in-class therapies for HIV,” said
The Phase 2 study will evaluate GS-7340 as part of a once-daily, co-formulated single-tablet regimen that will also contain the boosting agent cobicistat, the integrase inhibitor elvitegravir, and Emtriva® (emtricitabine). The GS-7340-containing single-tablet regimen will be compared to Gilead’s Quad single-tablet regimen, which contains Viread and Emtriva (as Truvada®), elvitegravir and cobicistat, and is currently under review for marketing approval by U.S. and European regulatory agencies.
Gilead plans to initiate a second Phase 2 trial for GS-7340 later in
2012 that will assess GS-7340 as part of another single-tablet regimen
containing cobicistat, Emtriva and Tibotec Pharmaceuticals’ protease
inhibitor Prezista® (darunavir). Gilead announced an
agreement with Tibotec to develop this single-tablet regimen on
Viread was approved for HIV treatment in 2001 and has accumulated more than 4.4 million patient years of clinical experience to date.
About the GS-7340 Phase 2 Study
The Phase 2 study is a randomized, double-blind 48-week clinical trial among HIV-1 infected adults with HIV RNA levels (viral load) greater than or equal to 5,000 copies/mL and CD4 cell counts greater than 50 cells/mm3. A total of 150 patients will be randomized (2:1) to receive a once-daily tablet containing GS-7340 10 mg/cobicistat 150 mg/elvitegravir 150 mg/emtricitabine 200 mg (n=100) or the Quad (tenofovir disoproxil fumarate 300 mg/cobicistat 150 mg/elvitegravir 150 mg/emtricitabine 200 mg) (n=50). The HIV virus of participants must be sensitive to both tenofovir and emtricitabine, prior use of antiretrovirals is not allowed and participants must have adequate renal function (defined as an estimated glomerular filtration rate of greater than or equal to 70 mL/min, according to the Cockcroft-Gault formula).
The primary endpoint will be the proportion of patients with viral load
less than 50 copies/mL at 24 weeks of treatment as determined by the
Additional information about the study can be found at www.clinicaltrials.gov.
GS-7340 is a novel prodrug of tenofovir, the active agent in the company's HIV drug Viread. Like Viread, GS-7340 is a nucleotide reverse transcriptase inhibitor (NtRTI). Phase 2a dose-ranging studies have identified a dose that is ten times lower than Viread and provides greater antiviral efficacy. The smaller milligram size of GS-7340 may enable the development of new fixed-dose combinations and single-tablet regimens for HIV therapy that are not feasible with Viread.
Cobicistat is a potent mechanism-based inhibitor of cytochrome P450 3A
(CYP3A), an enzyme that metabolizes drugs in the body. Gilead is
evaluating cobicistat in three separate pivotal Phase 3 studies, both as
a stand-alone boosting agent for protease inhibitors, as well as part of
the Quad regimen. Gilead has exclusive rights to develop cobicistat
worldwide, except for
As an integrase inhibitor, elvitegravir interferes with HIV replication
by blocking the ability of the virus to integrate into the genetic
material of human cells. Elvitegravir was licensed by Gilead from
The Quad is a single-tablet regimen that contains elvitegravir,
cobicistat, emtricitabine and tenofovir disoproxil fumarate. In
GS-7340, cobicistat, elvitegravir and the Quad are investigational products and their 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 our ability to enroll patients in the Phase 2 clinical trial
of a single-tablet regimen containing elvitegravir, cobicistat,
emtricitabine and GS-7340, our ability to initiate the Phase 2 trial of
a single-tablet regiment containing cobicistat, emtricitabine, darunavir
and GS-7340, the possibility of unfavorable results of this or other
clinical trials involving GS-7340, the need to modify or delay the
clinical trials or to perform additional trials and the risk of failing
U.S. full prescribing information for Viread is available at www.Viread.com.
U.S. full prescribing information for Truvada is available at www.Truvada.com.
U.S. full prescribing information for Emtriva is available at www.GileadHIV.com.
Viread, Truvada and Emtriva are registered trademarks of
For more information on
Gilead Sciences, Inc.
Susan Hubbard, 650-522-5715 (Investors)
Erin Rau, 650-522-5635 (Media)