Clinical Trial Shows Injection Twice a Year 100% Effective in HIV Treatment

Large-scale clinical trials conducted in Uganda and South Africa have revealed a groundbreaking advancement in HIV prevention. The trials demonstrated that a novel pre-exposure prophylaxis (PrEP) medication, administered twice a year, completely protects young women from HIV infection. This discovery offers a promising new method for managing the virus, especially for those who struggle with daily medication adherence.

The Purpose 1 trial, led by principal investigator Linda-Gail Bekker, tested the efficacy of two different drugs: daily pills and an injection of Lenacapavir.

Lenacapavir, also known as Len LA, is a fusion capsid inhibitor that interferes with the HIV capsid—a protein envelope that protects the virus's genetic material and essential replication enzymes. Administered subcutaneously once every six months, lenacapavir proved to be a formidable defense against HIV.

The randomized controlled trial included 5,000 participants across three locations in Uganda and 25 sites in South Africa. The trial had three primary objectives:

1. To determine if a six-monthly injection of lenacapavir was safe and more effective in preventing HIV infection among women aged 16 to 25 years compared to Truvada (F/TDF), a daily PrEP pill widely used for over a decade.

2. To assess whether Descovy (F/TAF), a newer daily pill with superior pharmacokinetic properties, was as effective as Truvada. Pharmacokinetics refers to how a drug moves into, through, and out of the body.

3. To evaluate the overall efficacy and safety of lenacapavir in comparison to the other medications.

The trial included three arms, with participants randomized in a double-blind manner in a 2:2:1 ratio (Len LA: Truvada oral: Descovy oral). This means that neither the participants nor the researchers knew which treatment was being administered until the trial concluded.

Remarkably, during the randomized phase of the trial, none of the 2,134 women who received lenacapavir contracted HIV, resulting in a 100% efficacy rate. In contrast, 16 of the 1,068 women (1.5%) who took Truvada (F/TDF) and 39 of the 2,136 women (1.8%) who received Descovy (F/TAF) contracted HIV.

“With zero infections and 100% efficacy, twice-yearly lenacapavir has demonstrated its potential as an important new tool to help prevent HIV infections. We look forward to additional results from the ongoing PURPOSE clinical program and continuing toward our goal of helping to end the HIV epidemic for everyone, everywhere,” said Merdad Parsey, MD, PhD, Chief Medical Officer, Gilead Sciences.

This breakthrough holds immense promise as a highly effective prevention tool to protect people from HIV. With 1.3 million new HIV infections globally in the past year—down from 2 million in 2010—it is evident that more needs to be done to meet the UNAIDS target of fewer than 500,000 new infections by 2025 and ultimately end AIDS by 2030.

In conclusion, the development of lenacapavir as a biannual injection for HIV prevention represents a significant advancement in the fight against the virus. By providing a reliable and effective alternative to daily medication, this innovation has the potential to transform HIV prevention strategies and significantly reduce the global incidence of HIV infections.