Background:
Cabotegravir long-acting (CAB LA) was approved as pre-exposure prophylaxis (PrEP) for the prevention of HIV by the FDA on 20DEC2021. It is initiated with two 600mg injections given one month apart (initiation injections), followed by a 600mg injection every two months. We aimed to describe uptake of CAB LA for PrEP and injection patterns in routine clinical care in the US.
Methods:
Individuals ≥12 years old who received ≥1 CAB LA injection between 21DEC2021 and 31MAR2023 in the OPERA cohort were followed through 30JUN2023. Incomplete initiation was defined as the receipt of the first injection, with no additional injection within 68 days of the first. Discontinuation and non-adherence were assessed among complete initiators. Discontinuation was defined as ≥128 days without a CAB LA injection. Non-adherence consisted of ≥1 delayed or missed injection (see Table for definitions). Baseline characteristics were compared between adherent and non-adherent individuals. Multivariable logistic regression was used to assess predictors of non-adherence.
Results:
Of 560 CAB LA for PrEP users identified, 13% were women, 32% Black, 29% Hispanic, and 26% had a BMI ≥30; median age was 31 years (IQR 25-38). Within 12 months prior to CAB LA for PrEP initiation, 42% of individuals had an STI diagnosed and the median number of HIV tests was 3 (IQR: 2, 5). The initiation injections were completed by 498 individuals (89%) who had a median of 4 injections over a median 7 months of follow-up. Of the 498 with ≥2 injections, 7% discontinued CAB LA for PrEP (Table). Over two-thirds of CAB LA users received all injections on-time and 11% missed an injection (Table). Those with prior PrEP use were more likely to have delayed or missed injections (32%) than those without (21%), with a non-statistically significant odds ratio of 1.78 (95% CI: 0.91, 3.47). Oral bridging was not well documented in EHR; oral PrEP for oral bridging may be prescribed at the start of CAB LA injections but actual use is difficult to ascertain. There was 1 HIV seroconversion concurrent with third injection (all on time); HIV testing at oral PrEP start but not at CAB LA PrEP start.
Conclusions:
Early adoption of CAB LA for PrEP was successful in OPERA, a US cohort of EHR from routine clinical care. A sizeable proportion of CAB LA PrEP initiators had diagnoses of STI and multiple HIV tests in the preceding 12 months. While 11% of individuals missed an injection, this may be an overestimate of true therapeutic gaps if oral bridging was used.
