Projected Impact of Concurrently Available Long-Acting Injectable and Daily-Oral HIV Pre-Exposure Prophylaxis: A Mathematical Model.

BACKGROUND Long-acting injectable HIV pre-exposure prophylaxis (LAI-PrEP) is reportedly efficacious, although full trial results have not been published. We used a dynamic network model of HIV transmission among men who have sex with men (MSM) to assess the population impact of LAI-PrEP when available concurrently with daily-oral (DO) PrEP. METHODS The reference model represents the current HIV epidemiology and DO-PrEP coverage (15% among indicated) among MSM in the southeastern US. Primary analyses investigated varied PrEP uptake and proportion selecting LAI-PrEP. Secondary analyses evaluated uncertainty in pharmacokinetic efficacy and LAI-PrEP persistence relative to DO-PrEP. RESULTS Compared to the reference scenario, if 50% chose LAI-PrEP, 4.3% (95% SI: -7.3%, 14.5%) of infections would be averted over 10 years. LAI-PrEP impact is slightly greater than the DO-PrEP only regimen based on assumptions of higher adherence and partial protection after discontinuation. If the total PrEP initiation rate doubled, 17.1% (95% SI: 6.7%,26.4%) of infections would be averted. The highest population-level impact occurred when LAI-PrEP uptake and persistence improved. CONCLUSIONS If LAI-PrEP replaces DO-PrEP, its availability will modestly improve the population impact. LAI-PrEP will make a more substantial impact if its availability drives higher total PrEP coverage, or if persistence is greater for LAI-PrEP.