An injected drug given every two months has shown superiority to an approved oral drug in preventing HIV infection, according to newly presented data.
ViiV Healthcare – controlled by London-based GlaxoSmithKline, New York-based Pfizer and Osaka, Japan-based Shionogi – said Tuesday that in the final data analysis of the 4,600-participant Phase IIb/III HPTN 083 study comparing the injected drug cabotegravir against Gilead Sciences’ oral Truvada (emtricitabine, tenofovir disoproxil fumarate) as a pre-exposure prophylaxis, or PrEP, 13 participants on the ViiV drug became HIV-positive, compared with 39 of those receiving Truvada. This was despite medication adherence being high among Truvada users, as measured by concentrations of tenofovir.
“This advancement has the potential to be a game-changer for HIV prevention, offering an option with very high rates of effectiveness and the convenience of reduced dosing from daily to just six times per year,” ViiV head of research and development Kimberly Smith said in a statement. “We are thrilled with the results not only because of the high effectiveness of cabotegravir, but also because this study adequately represents some of the populations most disproportionately impacted by HIV – black MSM in the U.S., young MSM globally and transgender women.”
Both drugs were well-tolerated in the trial, which enrolled men and transgender women who have sex with men. Injection site reactions, high blood pressure and fever were more common among participants receiving cabotegravir, while more of those taking Truvada experienced nausea. The trial was double-blinded, with participants in the Truvada arm receiving placebo injections.
ViiV said it plans to use the data from HPTN 083 for future regulatory submissions. The company is running an additional trial, 084, which is being conducted among 3,200 women in several African countries.
The latest news follows the May announcement that HPTN 083 would be stopped early after an interim analysis showed that it was superior to Truvada, with a 69% greater efficacy at preventing HIV than the Gilead drug, which is taken daily.
Truvada, which received Food and Drug Administration approval for PrEP in 2012, is expected to lose patent protection and go generic in the fall. Gilead has since won FDA approval for another drug, Descovy (emtricitabine, tenofovir alafenamide), which comes without the bone and other side effects sometimes associated with Truvada.
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