The TAIL-PrEP Study: Acceptability and Feasibility of a Tailored Adherence Intervention for Safe Discontinuation of Long-acting PrEP

Oral PrEP is highly effective but underutilized, with only 25% of individuals eligible for PrEP in the US having a prescription. Recent approval of cabotegravir-LA (cab-LA), a long-acting injectable integrase inhibitor and the first long-acting injectable PrEP, and lenacapavir (LEN), a long-acting class capsid inhibitor presents an opportunity to increase uptake. However, the long and variable half-life of cab-LA across different individuals after discontinuation (called the "tail") poses an implementation challenge. During the tail, cabotegravir levels are sub-therapeutic but could select for integrase-inhibitor resistance if the patient were to acquire HIV. This concern about the tail presents a barrier to providers prescribing cab-LA, potentially limiting the contribution of cab-LA to achieving End the HIV Epidemic targets and PrEP uptake and HIV infection. Currently, to mitigate this risk, individuals are advised to use oral PrEP for up to and beyond 12 months after stopping cab-LA injections if they have an ongoing risk of becoming infected with HIV. However, a risk mitigation strategy that requires daily oral PrEP may not be feasible or acceptable to many patients who started injectable PrEP precisely because they were unable or unwilling to adhere to a daily medication. LEN does not pose the same issue with a drug tail during discontinuation, but patients discontinuing LEN may need guidance on how to switch to other HIV prevention strategies rather than discontinuing HIV prevention altogether. In Aim 1, the study will pilot test and assess the acceptability and feasibility of the TAIL-PrEP intervention: for participants discontinuing cab-LA, this will consist of monthly cabotegravir drug level monitoring to provide personalized HIV prevention coaching, for participants considering discontinuing cab-LA or LEN, this will consist of a one-time personalized HIV prevention coaching session. In Aim 2, the study will refine the TAIL-PrEP intervention and implementation strategy based on findings from the pilot study.