Injectable agents for pre-exposure prophylaxis: lessons learned from contraception to inform HIV prevention.

Overview

PURPOSE OF REVIEW: Long-acting injectable (LAI) forms of preexposure prophylaxis (PrEP) are in clinical trials, generating much hope for HIV prevention. But this is not the first time that an injectable form of preventive medication has emerged: the contraceptive agent depomedroxyprogesterone acetate (DMPA) has an important precedent. DMPA's long journey, its initial reception, and ongoing implementation challenges can help inform the field of HIV prevention as we plan for approval, acceptance, and scale-up of LAI-PrEP. RECENT FINDINGS: DMPA faced a long regulatory journey in the USA, with a lag of 25 years from initial application (1967) to approval (1992). Acceptance after introduction was rapid, but challenges hampered scale-up. Specific lessons learned include that extensive acceptability work is needed in parallel to product development. Also, low continuation rates, challenges with timing of initiation, and difficulty ensuring access for the most vulnerable populations have limited DMPA's impact. A new subcutaneous formulation presents opportunities for administration outside of clinical settings and for self-administration. SUMMARY: Those involved in LAI-PrEP development and those who plan to be involved in its future implementation must consider these lessons and possible solutions from DMPA to ensure a successful future for this new HIV prevention modality.