A report in AIDS and Behavior found that preferences for long-acting injectable cabotegravir for PrEP versus other methods was high, especially at non-US sites.
Efficacy of oral PrEP with tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) varies across different populations. While differential tissue penetrance may account for some variations, adherence appears to be a major factor. Long-acting injectable (LAI) products could address some current challenges of taking daily medication. Two LAIs (TMC278/rilpivirine [RPV LA] and GSK1265744/cabotegravir [CAB LA]) have been evaluated for safety and acceptability. While RPV LA is not currently being further evaluated, phase 3 CAB LA studies continue, evaluating experiences of pain and overall interest in injectable PrEP (ECLAIR sub-studies).
HPTN 077 was a randomised, double-blind, placebo-controlled phase 2a trial in HIV-uninfected, low-risk males and females (n=199). The aim was to assess the acceptability of injectable product attributes and to evaluate male and female future interest in using an injectable PrEP. Two cohorts were enrolled to receive either, 800 mg intramuscularly (two 2 mL injections), every 12 weeks for 3 cycles, or placebo (ratio 3:1), or 600 mg (single 3 mL injection) every 8 weeks for 5 cycles, or placebo (ratio 3:1). Each cohort received 4 weeks of daily oral pills as a run-in safety period, and a 1-week wash-out.
Acceptability of product attributes, prevention preferences, and future interest in injectable PrEP (FIIP) by region, sex-at-birth, arm, and cohort were measured. Baseline injectable PrEP preferences were higher in non-US sites, increasing in both regions over time. FIIP was most strongly associated with the acceptability of product attributes and was higher in non-US sites. Treatment arm and report of pain were not associated with FIIP. Injectable acceptability was highest in non-US sites. Preferences for injectable versus other PrEP methods were higher among US males than females.
Long-acting injectable PrEP acceptability was high, especially at non-US sites.