Background:
Cabotegravir (CAB) long acting (LA) for pre-exposure prophylaxis (PrEP) was approved in the United States in December 2021 to reduce the risk of sexually acquired HIV-1 infection. The Centers for Disease Control and Prevention (CDC) guidelines state that both HIV antigen (Ag)/antibody (Ab) and HIV RNA testing should be conducted at every injection. Real-world testing, effectiveness, and adherence were assessed among individuals initiating CAB LA for PrEP in the US.
Methods:
Individuals without HIV initiating CAB LA for PrEP were identified from electronic health record data in the Trio Health cohort between December 2021-May 2023. HIV testing and incidence were assessed among individuals with at least one injection of CAB LA. HIV testing was assessed at baseline within 90 days prior to the first injection and during follow-up within ±14 days of injection. Incident HIV was identified with either a positive HIV Ag/Ab lab result with confirmatory HIV RNA test or one detectable HIV RNA. Adherence was assessed among individuals with ≥2 injections of CAB LA. On-time injections were defined as occurring within ±7 days of target date and missed injections were defined as a missed injection cycle.
Results:
Among the 85 individuals with at least one documented injection of CAB LA for PrEP, the majority were male (93%), White (60%), from the Southern region of US (82%), and the median age was 41 years. Prior to initiation, all individuals had at least one documented HIV Ag/Ab or HIV RNA, and 77% had both tests. During follow-up, 74% of individuals had either HIV Ag/Ab or HIV RNA results at all injections, while 44% had HIV Ag/Ab results, 40% had HIV RNA results, and 20% of individuals had both HIV RNA and HIV Ag/Ab results. No incident HIV diagnoses were identified. Of the 64 individuals with ≥2 injections of CAB LA, 48 (75%) had on-time 2nd injection (Table). Among 43 individuals with ≥3 injections, 27 (63%) had all injections after 2nd on-time. There were no missed injections. 94% continued on CAB LA for PrEP at analysis date.
Conclusions:
Initial data from Trio cohort suggest CAB LA for PrEP is effective at preventing HIV acquisition. Injections were administered on-time among the majority of individuals. HIV testing practices in this real-world setting during the early days of CAB LA for PrEP did not align with the CDC testing guidelines among a significant proportion of users.
