Developing a drug-level feedback adherence counseling intervention for young MSM in the U.S.

BACKGROUND: Young men who have sex with men (MSM) in the U.S. have suboptimal adherence to oral tenofovir-based pre-exposure prophylaxis (PrEP), undermining HIV prevention goals. Drug-level feedback using urine point-of-care tenofovir assays has improved adherence in Eastern and Southern African settings but has not been assessed among U.S. MSM. SETTING: Community-based PrEP clinic in San Francisco and home-based remote counseling sessions among young MSM across the U.S. METHODS: A two-phase study was conducted. Phase 1 involved qualitative interviews with 20 young MSM (mean age 25.7 years) from a San Francisco PrEP clinic, guided by the COM-B model and Behavior Change Wheel framework to identify barriers to adherence, informing the development of the PrEP2-BAY intervention. Phase 2 pilot-tested the PrEP2-BAY intervention remotely among 20 MSM (mean age 27.7 years), using at-home urine tenofovir tests and counselor-led feedback and action planning via Zoom. Acceptability was assessed qualitatively through the Theoretical Framework of Acceptability. Urine tenofovir levels were compared pre- and post-intervention. RESULTS: Key barriers to PrEP adherence identified included mental health, substance use, relationship dynamics, and stigma. Participants preferred at-home testing with counselor guidance, leading to adaptation of PrEP2-BAY into an mHealth approach. In the pilot phase, participants reported high acceptability and perceived effectiveness. There was a trend toward improved urine tenofovir levels with all participants exhibiting positive urine test results post-intervention. CONCLUSIONS: PrEP2-BAY demonstrated high acceptability with a trend toward improved adherence among young MSM. Further evaluation through a randomized controlled trial is recommended to assess efficacy and support broader implementation.