In a significant development for global HIV prevention, the World Health Organization (WHO) has welcomed the latest findings from the PURPOSE-2 trial, which examined the long-acting injectable lenacapavir (LEN) as an HIV prevention method. These results, announced on September 12, 2024, highlight LEN’s promising potential in reducing HIV transmission, particularly for diverse populations including cisgender men, transgender men, transgender women, and gender non-binary individuals.
Lenacapavir, a first-of-its-kind HIV-1 capsid inhibitor, is delivered through subcutaneous injections every six months. The trial’s interim analysis revealed that LEN offers exceptional protection against HIV, demonstrating a 96% reduction in the risk of acquiring the virus. Among the 2,180 participants who received the bi-annual LEN injections, only two new HIV infections were recorded. This stands in stark contrast to the nine infections observed among 1,087 participants using the traditional daily oral PrEP combination of tenofovir disoproxil fumarate/emtricitabine (TDF/FTC).
Key Findings from the PURPOSE-2 Trial
The trial, which enrolled a total of 3,267 participants across eight countries, showed that LEN was 89% more effective than daily oral TDF/FTC in preventing HIV acquisition. Additionally, the reduction in HIV incidence with LEN was 96% when compared to the background HIV incidence rate of 2.37 per 100 person-years. Both LEN and daily oral TDF/FTC were well tolerated by participants, with no significant new safety concerns raised during the study.
These findings are groundbreaking, offering further confirmation of LEN’s efficacy in preventing HIV across diverse groups. The results from the PURPOSE-2 trial complement earlier research from the PURPOSE-1 trial, which demonstrated the injectable’s effectiveness in preventing HIV among cisgender women in sub-Saharan Africa. This combination of results highlights LEN’s broad potential to address HIV prevention needs worldwide.
The Promise of Lenacapavir in HIV Prevention
The approval of LEN could revolutionize HIV prevention, particularly for individuals who face barriers to adhering to daily oral PrEP regimens. These barriers include stigma, discrimination, pill fatigue, and inconsistent access to medication. Lenacapavir’s twice-yearly dosing offers a substantial advantage, providing a more convenient option for those who struggle with the daily routine of taking oral PrEP. This could dramatically improve adherence and ultimately reduce HIV transmission rates in high-risk populations.
Moreover, LEN’s potential for scaling globally is immense. WHO is already in the process of convening an expert group to assess the full potential of LEN for HIV prevention, including its efficacy, safety, cost-effectiveness, and accessibility. The WHO will also collaborate with international partners, including pharmaceutical companies and generic manufacturers, to ensure affordable, equitable access to LEN for those who need it most.
A Growing HIV Prevention Toolkit
LEN’s inclusion in the list of HIV prevention options is a crucial step forward. It joins other recent advancements such as the oral PrEP regimen (TDF/FTC), the dapivirine vaginal ring (DVR), and long-acting cabotegravir (CAB-LA). With these options, public health efforts are better equipped to tackle HIV transmission, particularly in regions with high incidence rates, such as sub-Saharan Africa and other parts of the global south.
The promising results from the PURPOSE-2 trial position lenacapavir as a potentially transformative tool in the fight against HIV. By offering an alternative to daily oral medications, LEN could increase the accessibility and effectiveness of HIV prevention strategies for a wide range of at-risk populations. As WHO and its partners work towards scaling up access to LEN, the potential for reducing global HIV transmission has never been more within reach.
