HIV Prevention Breakthroughs Take Center Stage at IAS 2025

The International AIDS Society (IAS) 2025 conference in Kigali, Rwanda has become a showcase for the latest advancements in HIV prevention and treatment, with pharmaceutical giants Gilead, ViiV Healthcare, and Merck presenting groundbreaking data on their respective pre-exposure prophylaxis (PrEP) offerings.

Gilead's Yeztugo Demonstrates Efficacy in Diverse Populations

Gilead Sciences, fresh from the landmark U.S. approval of Yeztugo, a twice-yearly injectable PrEP, has presented additional data from its Phase III PURPOSE program. The studies show that Yeztugo is "efficacious and well tolerated" in vulnerable patient populations, including pregnant and lactating women, and young people aged 16 to 25.

In the PURPOSE 1 study, which enrolled cisgender women and adolescent girls across sub-Saharan Africa, none of the 184 pregnant and lactating women treated with Yeztugo contracted HIV. The safety profile was comparable to that of non-pregnant women, with minimal infant exposure through breastfeeding.

Data from PURPOSE 1 and PURPOSE 2 studies demonstrated Yeztugo's efficacy in young people, with only two cases of HIV detected after treatment. Gilead also presented modeling data suggesting that Yeztugo can retain its efficacy in patients with tuberculosis when given at a slightly altered dosing regimen.

Gilead is actively pursuing global regulatory clearances for Yeztugo and has signed an agreement with the Global Fund to provide the HIV prophylactic to low- and middle-income countries simultaneously with high-income countries.

ViiV Healthcare's Apretude Shows Promise in Real-World Studies

ViiV Healthcare, a joint venture between GSK, Pfizer, and Shionogi, presented data from the PILLAR and EBONI implementation trials for Apretude, their long-acting PrEP administered every other month. The studies demonstrated that Apretude is both acceptable and feasible for patients across different demographic groups, including transgender men, Black women, and men who have sex with men (MSM).

The EBONI study, focusing on Black cis- and transgender women, found Apretude to be "highly appropriate" and "feasible" for HIV prevention in this population. In the PILLAR study, which enrolled MSM and transgender men, 95% of participants reported being "happy" with switching from oral PrEP medications to Apretude.

ViiV also shared data from real-world studies on Cabenuva, their injectable combination of cabotegravir and rilpivirine for HIV treatment. The Phase IIIb VOLITION study showed that 89% of virally suppressed HIV patients chose to switch to Cabenuva from oral daily pills, citing convenience and reduced worry about missed doses. The BEYOND study found that 97% of patients switching to Cabenuva maintained viral suppression at 24 months.

Merck Advances Monthly Oral PrEP to Phase III Trials

Merck announced the launch of the Phase III EXPrESSIVE program to study MK-8527, a once-monthly oral nucleoside reverse transcriptase translocation inhibitor for HIV prevention. The program includes two major trials: EXPrESSIVE-11, set to enroll over 8,500 high-risk participants across 16 countries starting in August, and EXPrESSIVE-10, focusing on women and adolescents in sub-Saharan Africa.

Phase II data for MK-8527, to be presented at IAS 2025, has supported its advancement to late-stage development with encouraging pharmacokinetic and safety findings from a study of 350 low-risk individuals.

This program marks Merck's return to late-stage PrEP development following the discontinuation of their oral islatravir program in September 2022 due to safety concerns. However, Merck continues to pursue islatravir as a therapeutic option for HIV patients, with the FDA recently accepting a new drug application for a combination regimen with doravirine for adults with virologically suppressed HIV-1.