Transitioning to long-acting pre-exposure prophylaxis (PrEP) and expanding coverage to achieve meaningful reductions in HIV incidence among adolescent girls and young women is important. If coverage can be effectively scaled up, lenacapavir has the potential to significantly reduce the burden of HIV among adolescent girls and young women.
Oral HIV PrEP has not achieved its full potential, mainly due to challenges involving adherence and consistent use. To increase uptake and effectiveness, alternative delivery methods are needed. The long-acting injectable medication lenacapavir, administered twice a year, offers a promising solution.
The researchers used modeling to assess the potential impact of lenacapavir on HIV outcomes among high-risk adolescent girls and young women in Kenya.
They used a deterministic transmission-dynamic compartmental model of HIV infection calibrated to Kenya to simulate PrEP implementation scenarios. In their analysis, oral PrEP, which had been introduced in 2018, was assumed to be used exclusively by HIV-negative girls 15-24 years of age who were at high risk, considered to be having sex with five partners per year, reaching 4.6% coverage by 2025.
Starting in 2026, the authors assumed a national switch in Kenya to long-acting injectable lenacapavir with five possible trajectories by 2030: 1.) maintaining 2025 coverage levels, or increasing to 2.) 15%, 3.) 30%, 4.) 45%, or 5.) 57% coverage. They also modeled a comparator scenario that assumed no switch to lenacapavir and no scale-up beyond 2025 oral PrEP coverage levels.
The researchers considered oral PrEP to be 75% effective and lenacapavir 100% effective in preventing HIV infection. They calculated the median and interquartile range (IQR) of new HIV cases and cumulative cases averted over 30 years across the 25 best-fitting parameter sets.
The greatest impact of lenacapavir among adolescent girls and young women was found at higher coverage levels. At 57% coverage, the medication was estimated to avert 11,904.93 (9,293.73-17,027.33) new HIV cases, representing an 18.82% (18.34%-19.62%) reduction compared to oral PrEP. However, switching to lenacapavir alone without scaling up coverage had a modest effect. At 4.6% coverage, the reduction in HIV acquisition was only 0.58% (0.57%-0.61%). A small increase to 15% coverage averted 2,974.52 (2,322.97- 4,274.46) HIV cases, while scaling to 30% averted around 6,445.65 (5,036.58- 9,248.84) infections.
Reference
IAS 2025. Oral abstract session with live Q&A; Program number OAC0406LB.
