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HIV Prevention in the Asia Pacific
Advancing HIV Prevention in Asia Pacific: Insights From CROI 2025 on PrEP Innovations and Challenges

Released: April 08, 2025

Expiration: April 07, 2026

Iskandar Azwa
Iskandar Azwa, MD
Activity Information

Activity

Progress
1
Course Completed
Key Takeaways
  • New CROI data on prevention explored expansion of event-driven PrEP to include cisgender women.
  • Disruptions in US foreign aid threaten the sustainability of HIV prevention programs in the Asia Pacific region, emphasizing the urgent need for alternative funding mechanisms and policy adaptations to maintain progress in HIV prevention efforts.

The Conference on Retroviruses and Opportunistic Infections (CROI) 2025 was the first major HIV conference to be held after the suspension of PEPFAR and USAID funding this past January. Despite current uncertainties, investigators presented pivotal research with significant implications for HIV prevention strategies in the Asia Pacific region.

Impact of US Foreign Aid Suspension on HIV Prevention Services
During the opening plenary, professor Chris Beyrer, director of the Duke Global Health Institute, took center stage with a powerful speech that emphasized 3 critical words for our HIV response: diversity, equity, and inclusion. Over the past 2 decades, the United States HIV response has embodied these principles. However, Professor Beyrer warned that the freeze on all US foreign aid assistance threatens this historic progress in the global scale-up of HIV treatment and prevention.

In fact, the global HIV response was falling short of its targets in the Asian Pacific region even before the pause in US foreign aid funding. This region is home to the second largest HIV epidemic after Eastern and Southern Africa, with an estimated 300,000 new HIV infections in 2023, according to the 2024 Global AIDS Update Report. Between 2010 and 2023, there was only a 13% decline in new infections, significantly lower than the global average reduction of 39%. Seventy-nine percent of new HIV infections in Asia Pacific are concentrated in key populations and their partners, highlighting the acute need for HIV prevention services in this region.

It is regrettable that HIV prevention has been greatly impacted because of the loss in PEPFAR and USAID funding. PEPFAR supports more than 90% of all global pre-exposure prophylaxis (PrEP) initiations, and all HIV prevention programs under PEPFAR, aside from Prevention of Mother to Child Transmission, are currently on hold. To put things into context, it is widely accepted that there is no PrEP program globally without PEPFAR. In Asia Pacific, the hardest hit have been community-led organizations that provide prevention and psychosocial support services for persons most affected by HIV.

This disruption of US foreign aid to countries in Asia Pacific that rely heavily on them emphasizes the need for new, diversified, and sustainable financing strategies to maintain continuity of HIV prevention programs in these countries. To avoid disruptions in service delivery, I believe that domestic funding must be strengthened through reducing operational costs, expanding partnerships with the private sector, and supporting the replenishment of the eighth round of the Global Fund.

Potential for Yearlong HIV Protection in 1 Dose
Fortunately, the abstracts presented at CROI also provide hope for the future of HIV prevention, particularly in terms of more flexible, on-demand regimens and long-acting PrEP.

Phase I pharmacokinetic and safety data on 2 formulations of once-yearly, intramuscular lenacapavir, a long-acting HIV-1 capsid inhibitor, were presented. Investigators reported that both formulations maintained higher median plasma concentrations than the twice yearly subcutaneous lenacapavir used in the PURPOSE studies over 56 weeks, supporting annual dosing for PrEP in subsequent larger phase III studies.

The most common side effect was injection-site pain, which typically resolved in 1 week and decreased with pretreatment with ice.

In the Asia Pacific, where PrEP persistence on oral tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) has been a challenge due to stigma and healthcare access, a once yearly PrEP injection could significantly increase uptake and adherence and reduce the number of clinic visits.

Event-Driven PrEP for Cisgender Women
Use of event-driven oral TDF/FTC PrEP, also known as the 2-1-1 regimen, is traditionally recommended for men who have sex with men, leaving a significant research and knowledge gap regarding its efficacy in cisgender women. A modeling study presented by Mackenzie Cottrell, using a previously published pharmacokinetics/pharmacodynamics (PK/PD) model of the female genital tract, suggested that a modified event-driven PrEP regimen could also be effective for cisgender women.

Data from this study showed that extending the traditional 2-1-1 regimen to a 4-day dosing schedule resulted in 80% of the simulated model profiles achieving protective PK/PD levels of drug, which could translate to an 8% to 15% increase in protection compared to the 2-1-1 regimen.

Specifically, the model demonstrated that a 2-1-1-1 dosing regimen could provide 84% protection from HIV infection at 7 days post sex. Investigators speculated that this regimen could provide the best balance of safety, efficacy, and tolerability compared to other dosing regimens tested. If validated in clinical studies, this modified event-driven PrEP could offer cisgender women a more flexible HIV prevention option including in the Asia Pacific region, where uptake in women has been dismally low.

Your Thoughts
Although there are still many uncertainties regarding the future of HIV prevention and the path to eliminating HIV remains uncharted, these presentations from CROI 2025 provide hope in the form of innovative ways to make HIV prevention accessible to a broader range of people. How do these abstracts affect the way you approach HIV prevention for your patients?