A large clinical trial conducted in South Africa and Uganda has demonstrated that a biannual injection of a new pre-exposure prophylaxis (PrEP) drug provides total protection against HIV infection.

You read that right, 100% protection. How crazy is that?

This remarkable achievement is seen as a beacon of hope, particularly for young women in regions heavily burdened by the virus.

The Purpose 1 trial, which involved 5,000 participants, was conducted at three sites in Uganda and 25 sites in South Africa. The primary goal was to evaluate the efficacy of lenacapavir, a fusion capsid inhibitor, in preventing HIV infection compared to two existing daily PrEP pills, Truvada (F/TDF) and Descovy (F/TAF). Lenacapavir, administered as a subcutaneous injection every six months, interferes with the HIV capsid, a protein shell critical for the virus’s replication.

Dr. Linda-Gail Bekker, the principal investigator for the South African segment of the study, highlighted the significance of these findings.

During the randomized phase of the trial, none of the 2,134 women who received lenacapavir contracted HIV, achieving 100 percent efficacy. In contrast, 16 of the 1,068 women (1.5%) taking Truvada and 39 of the 2,136 women (1.8%) on Descovy contracted the virus.

These results were so compelling that an independent data safety monitoring board recommended ending the trial’s blinded phase, allowing all participants to choose their preferred PrEP method.

The success of lenacapavir as a biannual injection marks a significant advancement in HIV prevention. Dr. Bekker emphasized that this breakthrough provides a highly effective tool to protect individuals from HIV, particularly in regions where daily medication regimens are challenging to maintain due to social and structural barriers.

Globally, there were 1.3 million new HIV infections last year. Although this is a decrease from the 2 million infections in 2010, current rates suggest that global targets to reduce new infections and potentially end the AIDS epidemic by 2030 are unlikely to be met without new interventions like lenacapavir.

The Purpose 1 trial will continue in an open-label phase, where participants will be informed of their previous treatment group and can choose their preferred PrEP method.

Meanwhile, a sister trial, Purpose 2, is underway, focusing on cisgender men, transgender individuals, and nonbinary people who have sex with men across various regions, including Africa.

The next critical step involves regulatory approval. Gilead Sciences, the developer of lenacapavir, plans to submit the trial results to regulators in Uganda, South Africa, and potentially other countries within the next few months. The World Health Organization (WHO) will also review the data, which could lead to new global guidelines and recommendations.

Ensuring broad access to lenacapavir will require addressing pricing and distribution challenges. Gilead Sciences has expressed its intention to license the drug to generic manufacturers, a move that could significantly reduce costs and facilitate widespread distribution, especially in public health sectors where it is most needed.

The discovery of lenacapavir’s efficacy as a biannual HIV prevention method is a monumental step forward. If regulatory approvals proceed smoothly, this drug could revolutionize HIV prevention, offering a more practical and effective solution for millions at risk, particularly in high-burden areas.

With continued research and support, the goal of significantly reducing new HIV infections and ultimately ending the AIDS epidemic seems more attainable than ever.