February 24, 2016
Gilead Announces Data From New Preclinical Study Evaluating an Investigational TLR7 Agonist in SIV-Infected Monkeys
– Data Support Continued Investigation of GS-9620 as Part of an HIV Eradication Strategy –
“Our ultimate goal with TLR7 agonist therapy is to stimulate the body to
drive latent HIV out of viral reservoirs in infected cells and to
enhance virus-specific immune responses in HIV-infected individuals,”
Earlier research presented at CROI 2015 showed that GS-986 treatment, in combination with ART, reduced SIV DNA levels by 30 to 90 percent in some tissues. This follow-up study was designed to assess whether GS-9620 produced results similar to GS-986, and whether lower doses of the compounds would induce transient plasma viremia and/or perturb SIV viral reservoirs. A lower dose was chosen with the intent to minimize induction of peripheral interferon-alpha (IFN-alpha), an anti-viral protein that can cause adverse events.
In this placebo-controlled study, SIV-infected rhesus macaques received ART beginning day 65 post-infection. All animals achieved and maintained viral suppression (plasma RNA less than 50 copies/mL) through week 67 when they received 10 to 19 doses of either GS-9620 or GS-986 every other week.
TLR7 agonist dosing induced transient and variable increases in plasma SIV RNA levels across all treatment groups. After completing all doses of TLR7 agonist and prior to stopping ART, peripheral lymphocytes and lymph node biopsies from the animals had less inducible virus. Two of the TLR7 agonist-treated rhesus macaques maintained undetectable plasma viral load for more than 90 days after stopping ART.
“Today’s preliminary results give us deeper insight into how we might use GS-9620 effectively as we continue to focus on the potential role of TLR7 agonists in HIV eradication strategies,” said Norbert W. Bischofberger, PhD, Gilead’s Executive Vice President, Research and Development and Chief Scientific Officer. “We have advanced research on GS-9620 to a Phase 1b safety study in HIV-infected individuals taking ART and other GS-9620 studies are also underway, including one in patients with chronic hepatitis B for its potential to reduce HBsAg.”
The proprietary TLR7 agonist compounds GS-9620 and GS-986 are investigational agents, and their safety and efficacy have not 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. In addition, we may
observe unfavorable results from clinical trials involving proprietary
investigational TLR7 agonists, including GS-9620 and GS-986, as part of
an HIV eradication strategy. In addition, Gilead may make a strategic
decision to discontinue development of GS-9620 and other proprietary
investigational TLR7 agonists if, for example, Gilead believes
commercialization will be difficult relative to other opportunities in
its pipeline. As a result, GS-9620 and other proprietary investigational
TLR7 agonists may never be successfully commercialized. 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
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Patrick O’Brien, 650-522-1936 (Investors)
Ryan McKeel, 650-377-3548 (Media)