February 25, 2015
Gilead Announces Preclinical Data for an Investigational TLR7 Agonist in SIV-Infected, Virally Suppressed Monkeys
– Data Support Plans for Phase 2 Clinical Trial in Humans –
“One reason current therapies can’t cure HIV is that latent reservoirs
of the virus persist even among individuals who are virally suppressed
on ART,” said
In this placebo-controlled study, 10 SIV-infected rhesus macaques received ART for 38 weeks, at which point they were virally suppressed (plasma RNA less than 50 copies/mL). At week 38, six macaques were given placebo and four macaques were given seven bi-weekly doses of the TLR7 agonist, while maintaining ART. Total viral DNA levels were measured at baseline and two weeks after completion of the TLR7 agonist dosing in peripheral blood mononuclear cells (PBMC), colon and inguinal lymph nodes – where latent SIV reservoirs are common. ART was discontinued two weeks after the final dose of the TLR7 agonist to assess plasma viral rebound.
The four macaques receiving bi-weekly doses of the TLR7 agonist were given 0.1 mg/kg for the first dose, 0.2 mg/kg for the second dose and 0.3 mg/kg for each of the last five doses. Doses 1-3 had no effect on plasma viremia, whereas doses 4-7 led to transient and consistent increases in plasma virus (500-1,000 SIV RNA copies/mL) in all four macaques with a return to less than 50 copies/mL within four to seven days after receiving the TLR7 agonist. In addition, SIV DNA levels of the four treated macaques were reduced by 30 to 90 percent compared to the placebo group, which remained unchanged. Following discontinuation of ART in the macaques that received the TLR7 agonist, plasma SIV RNA was ~0.5 log10 lower compared to the placebo group.
“These preliminary results suggest that TLR7 agonists may have a role to
play in HIV eradication strategies,” said
The proprietary TLR7 agonist compound and GS-9620 are investigational agents and their safety and efficacy have not been established.
Gilead Sciences is a biopharmaceutical company that discovers, develops
and commercializes innovative therapeutics in areas of unmet medical
need. The company’s mission is to advance the care of patients suffering
from life-threatening diseases. Gilead has operations in more than 30
countries worldwide, with headquarters in Foster City,
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 the proprietary investigational TLR7 agonist or other TLR7 agonists, including GS-9620. In addition, Gilead may make a strategic decision to discontinue development of the proprietary TLR7 agonist or GS-9620 if, for example, Gilead believes commercialization will be difficult relative to other opportunities in its pipeline. As a result, the proprietary TLR7 agonist and GS-9620 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 September 30, 2014, as filed with the U.S. Securities and Exchange Commission. All forward-looking statements are based on information currently available to Gilead, and Gilead assumes no obligation to update any such forward-looking statements.
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Gilead Sciences, Inc.
Patrick O’Brien, Investors, 650-522-1936
Cara Miller, Media, 650-522-1616