Gilead's Lenacapavir's Proves 100% Efficacy in Preventing HIV in Cisgender Women

Gilead Sciences, Inc. has announced significant findings from its Phase 3 PURPOSE 1 trial, revealing that the trial demonstrated 100% efficacy in preventing HIV infection among cisgender women. The trial encompassed over 5,300 participants across South Africa and Uganda. This efficacy rate surpasses the efficacy rates of current standard PrEP options like Truvada and Descovy.¹

Lenacapavir offers a different approach with its twice-yearly injectable format, “Lenacapavir is a first-in-class, investigational long-acting HIV capsid that was FDA approved in late 2022 and is indicated for adult patients living with HIV, whose infections cannot be successfully treated with other available treatments due to resistance, intolerance, or safety consideration.”²

Pre-exposure prophylaxis (PrEP) involves taking prescription medicine routinely before potential exposure to HIV to reduce the risk of infection. According to the Centers for Disease Control and Prevention (CDC), when taken as prescribed, PrEP can reduce the risk of HIV transmission through sex by 99% and by at least 74% from injection drug use.³

The interim analysis, conducted by an independent Data Monitoring Committee, recommended halting the blinded phase of the trial due to these compelling results. Notably, lenacapavir showed zero cases of HIV infection among recipients, contrasting with an incidence rate of 2.41 per 100 person-years in the background HIV incidence group (bHIV) and the once-daily oral Truvada group.¹

The PURPOSE program represents the largest and most diverse HIV prevention trial initiative to date, focusing on innovation in science, trial design, and community engagement to address historical gaps in HIV prevention research, particularly in disproportionately affected communities.¹

In addition to cisgender women, Gilead is conducting similar trials under the PURPOSE umbrella across diverse populations, including cisgender men who have sex with men, transgender individuals, and gender non-binary individuals. Results from these trials are expected to inform regulatory submissions and potentially expand the use of lenacapavir for HIV prevention across multiple communities.¹

Detailed data from the PURPOSE 1 trial will be presented at upcoming conferences, providing further insights into lenacapavir's safety profile and long-term efficacy. Gilead remains committed to collaborating closely with affected communities and stakeholders to ensure equitable access to this promising HIV prevention option.¹

The second phase of the study will span from 1 to 3 years, with participant visits occurring every 4-13 weeks, totaling between 4 and 8 visits annually. Each participant in this phase will receive both a daily pill and a semiannual injection, with one containing the active drug and the other serving as a placebo.²

In conclusion, lenacapavir's 100% efficacy in the PURPOSE 1 trial represents a significant advancement in HIV prevention, potentially offering a more convenient and effective alternative to current PrEP options. The ongoing commitment to community engagement, safety monitoring, and regulatory processes will be pivotal in its successful adoption and impact globally. While the initial results are promising, ongoing studies will further assess long-term safety and any potential side effects.

References

1. Press Release. Gilead’s Twice-Yearly Lenacapavir Demonstrated 100% Efficacy and Superiority to Daily Truvada® for HIV Prevention. GILEAD. Published June 20, 2024. Accessed June 20, 2024. https://www.gilead.com/news-and-press/press-room/press-releases/2024/6/gileads-twiceyearly-lenacapavir-demonstrated-100-efficacy-and-superiority-to-daily-truvada-for-hiv-prevention

2. Parkinson, J. Examining a Newer Therapy for Heavily Treated HIV Patients. Contagion. Published March 7, 2024. Accessed June 20, 2024. https://www.contagionlive.com/view/examining-a-newer-therapy-for-heavily-treated-hiv-patients

3. Gilead. Purpose 1. https://www.purposestudies.com/purpose1/