麻豆传媒

SEATTLE -- Black individuals in the U.S. taking pre-exposure prophylaxis (PrEP) for HIV had substantial benefit with long-acting cabotegravir (Apretude), a substudy of the randomized the HPTN 083 trial showed, but they still faced a higher incidence of HIV than non-Black participants.

In the study of at-risk cisgender men who have sex with men and transgender women who have sex with men, HIV transmission rates among the Black U.S. participants were reduced from 2.11 per 100 person-years with the oral PrEP combination of tenofovir and emtricitabine (TDF-FTC) to 0.58 per 100 person-years with long-acting cabotegravir (HR 0.28, 95% CI 0.096-0.834), reported Hyman Scott, MD, of the University of California San Francisco.

"The protective efficacy of long-acting cabotegravir versus tenofovir-emtricitabine remained high among Black men who have sex with men and transgender women," Scott said at a press conference here during the annual Conference on Retroviruses and Opportunistic Infections.

Non-Black U.S. participants, meanwhile, saw their risk virtually eliminated, at 0.63 per 100 person-years with oral TDF-FTC versus 0 per 100 person-years with cabotegravir (HR 0.84, 0.004-2.060).

The difference in incidence was likely driven by adherence, Scott suggested. About 27% of the patients on TDF-FTC had low levels of adherence, as measured by drug levels in the body, whereas adherence with cabotegravir was 89.7% overall -- 83.1% among Black participants and 90.2% among non-Black participants.

"Tenofovir-emtricitabine adherence consistent with at least four doses a week was lower among Black men who have sex with men and transgender women," said Scott. "Long-acting cabotegravir is a powerful HIV prevention tool to increase access to PrEP and address continued racial disparities in HIV incidence in the United States."

In commenting on the study, press conference moderator Sharon Hillier, PhD, of the University of Pittsburgh, told 麻豆传媒 that "no PrEP product is going to be perfect," but that "the results with long-acting cabotegravir are very good."

"I think that long-acting cabotegravir is ready for prime time," she said. "The uptake will depend on whether third parties will be willing to pay for this agent."

The current study scrutinized data from the international HPTN 083 trial. Previously reported findings from the randomized study showed a significant reduction in incident HIV infection with cabotegravir versus oral TDF-FTC (0.41 vs 1.22 per 100 person-years; HR 0.34, 95% CI 0.18-0.62).

Participants in the study were first dosed with oral cabotegravir or placebo daily for 5 weeks; or were given TDF-FTC. Then the individuals were given injections of long-acting cabotegravir at weeks 5 and 9, and then every 2 months, for an expected 3 years. Those on TDF-FTC were given placebo injections.

The current analysis of U.S. participants included 1,495 cisgender men who have sex with men (93%) and transgender women who have sex with men (7%). Overall, this population received 18,475 injections. Some differences existed in baseline HIV factors between the Black and non-Black groups, including rates of recreational drug use in the past 6 months (62% vs 73%, respectively), active syphilis (4% vs 2%), rectal gonorrhea (6% vs 3%), and urine gonorrhea (1.1% vs 0.4%).

At data cutoff, there were 19 HIV infections in the 771 Black individuals: 15 in the TDF-FTC arm and four in the cabotegravir arm. Among the 722 non-Black population, there were five infections, all in those taking TDF-FTC.

About 60% of the participants in the study reported injection-site reactions, with the most frequent complaint being injection-site pain (17.3%) and tenderness (11.5%). Grade ≥3 injection-site reactions were reported by 2.2%.

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