Long-acting injectable cabotegravir (Apretude) offered greater protection than daily pre-exposure prophylaxis (PrEP) pills for Black gay and bisexual cisgender men and transgender women, but Black people still had higher HIV incidence rates compared with their white peers regardless of which type of PrEP they used, researchers reported at the 30th Conference on Retroviruses and Opportunistic Infections (CROI).
Adherence was higher with the every-other-month injections than with daily pills in both groups, suggesting long-acting PrEP could help close the racial gap in HIV rates. “[Apretude] is a powerful HIV prevention tool to increase access to PrEP and address continued racial disparities in HIV incidence in the United States,” Hyman Scott, MD, MPH, of the San Francisco Department of Public Health, and colleagues concluded.
Although African Americans make up about 13% of the U.S. population, they account for more than 40% of all new HIV diagnoses, so effective and acceptable prevention interventions are urgently needed. While white gay and bi men have readily adopted oral PrEP using tenofovir disoproxil fumarate/emtricitabine (Truvada and TDF/FTC generic equivalents) or tenofovir alafenamide/emtricitabine (Descovy), uptake has been lower among Black men.
Scott’s team evaluated the effectiveness of Apretude among Black gay and bisexual cisgender men and transgender women in the HPTN 083 trial, which compared Apretude injections given every two months to daily TDF/FTC. Based on the findings from this study and a companion trial in women (HPTN 084), the Food and Drug Administration approved Apretude for HIV prevention in December 2021.
The international trial enrolled 1,573 men who have sex with men and 125 trans women in the United States. Half (844 people) identified as Black, African American or mixed race including Black, and half (852 people) did not identify as Black. Overall, the participants were young; a majority were under age 30. At study enrollment, the two groups reported similar numbers of sex partners (a median of two) and receptive anal sex acts (a median of one) during the past month. Black participants were less likely to report recreational drug use during the past six months (62% versus 73%), but they were more likely to have sexually transmitted infections.
Over the course of the study, Black people were more likely to acquire HIV, but Apretude was highly protective for both groups. Among Black participants, HIV incidence was 2.11 cases per 100 person-years (15 new cases) in the TDF/FTC arm versus 0.58 per 100 person-years (four cases) in the Apretude arm—a 72% decline. Among non-Black participants, HIV incidence was 0.63 per 100 person-years (five cases) in the TDF/FTC arm versus 0 (no new cases) in the Apretude arm.
Lower adherence among Black participants assigned to TDF/FTC might help explain the difference, Scott suggested at a CROI media briefing. Testing of dried blood spots showed that Black people were less likely than non-Black people to have tenofovir drug levels consistent with taking at least four doses of TDF/FTC per week (65% versus 81%). Conversely, 24% of Black people and 10% of non-Black people had undetectable tenofovir levels. But both Black and non-Black participants usually received their Apretude injections on time (83% versus 90%, respectively).
“In this U.S. cohort of men who have sex with men and transgender women, while HIV incidence was higher among Black participants in both study arms, the protective efficacy of [Apretude] versus TDF/FTC was consistent,” the researchers concluded. “[Apretude] is a powerful HIV prevention tool to reduce HIV incidence among Black men who have sex with men and transgender women, and implementation must focus on ensuring access and addressing disparities in HIV incidence among these populations.”
Unfortunately, adoption of injectable PrEP has been slow. Although studies have found that many people would prefer long-acting injections over daily pills, Apretude involves six clinic visits per year, the cost is high and insurance coverage has been spotty. But this could change. Since 2019, insurers have been required to cover PrEP pills with no cost sharing because they are recommended at the highest level by the U.S. Preventive Services Task Force. In December, the task force gave Apretude an A grade in an updated draft recommendation, which means coverage would be mandated after the final recommendation is issued.
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