Merck Launches Global Access Plan for Once-Monthly HIV Prevention Pill Alimatravir

Merck has launched an early access strategy for investigational once-monthly oral HIV prevention therapy alimatravir (MK-8527), including voluntary licensing agreements across 129 low- and middle-income countries (LMICs) while Phase 3 clinical trials remain underway. The initiative aims to accelerate generic production and improve equitable access if the therapy receives regulatory approval.

Merck has outlined an ambitious global access strategy for alimatravir (MK-8527), an investigational once-monthly oral pre-exposure prophylaxis (PrEP) candidate for HIV-1 prevention. The company has signed voluntary licensing agreements with seven generic manufacturers, expanded regional manufacturing plans, and increased manufacturing investments well before Phase 3 trial completion. The move marks one of the earliest access initiatives announced for an HIV prevention medicine and reflects growing efforts to shorten the gap between regulatory approval and patient availability.

Early Licensing Strategy Targets High-Burden Countries

Merck’s royalty-free, non-exclusive licensing agreements cover 129 LMICs that account for the substantial majority of new HIV diagnoses worldwide. The agreements include three manufacturers based in sub-Saharan Africa, Aspen Pharmacare Holdings, Quality Chemical Industries Limited (Qcil), and UCL Kenya, along with four Indian manufacturers: Aurobindo, Cipla, Emcure, and Viatris. The licenses apply to both public and private healthcare sectors and allow partners to begin product development and regulatory preparation before potential approval.

According to the company, announcing voluntary licenses before completion of Phase 3 enrollment is unprecedented in HIV prevention and could accelerate large-scale implementation once regulatory decisions are made.

Addressing Persistent Gaps in HIV Prevention

Despite multiple HIV prevention options, including daily oral PrEP and long-acting injectable therapies, uptake remains below global targets. Approximately 1.2 million people acquired HIV in 2025, while UNAIDS reported only 3.5 million people used oral PrEP in 2023, far below the goal of reaching 20 million people by 2030. This gap underscores the urgency of expanding prevention modalities to meet the UNAIDS 2030 targets.

Alimatravir inhibits HIV reverse transcriptase through complementary mechanisms, including immediate chain termination by blocking reverse transcriptase translocation and delayed chain termination through structural changes in viral DNA. These pharmacologic properties support its development as a long-acting oral PrEP option.

Phase 3 Development Continues

The Phase 3 development program consists of two complementary global studies evaluating alimatravir as a once-monthly oral PrEP option.

EXPrESSIVE-10 (NCT07071623), supported by the Gates Foundation, is enrolling adolescent girls and young women in Kenya, South Africa, and Uganda, populations disproportionately affected by HIV in East Africa.

EXPrESSIVE-11 (NCT07044297) is enrolling people with a greater likelihood of HIV-1 exposure across 16 countries, evaluating the therapy in a broader global population. Both studies are assessing the safety and efficacy of once-monthly alimatravir for HIV prevention.

The Phase 3 program builds on encouraging findings from the Phase 2 MK-8527-007 study (NCT06045507), which enrolled 350 adults with a low likelihood of HIV exposure. Participants received monthly doses of 3 mg, 6 mg, or 12 mg alimatravir, or placebo, for six months. Adverse event rates were comparable between treatment and placebo groups, with no clinically meaningful changes in laboratory parameters, including total lymphocyte and CD4 T-cell counts. Pharmacokinetic data supported the continued development of alimatravir as a once-monthly oral PrEP candidate.

Executive Commentary

Merck Chairman and Chief Executive Officer Robert M. Davis said the company is advancing access planning before approval because scientific innovation delivers its greatest value only when patients can obtain treatment rapidly. He noted that the strategy reflects years of collaboration with HIV advocates, public health organizations, and global stakeholders to improve equitable access to HIV prevention.

External health leaders also welcomed the initiative. Gates Foundation CEO Mark Suzman said early licensing efforts could help communities most affected by HIV gain faster access to a new prevention option. Africa Centres for Disease Control and Prevention Director General Jean Kaseya highlighted the inclusion of African manufacturers as an important step toward strengthening regional health manufacturing capacity and long-term supply resilience.

Future Development

Merck is expanding internal manufacturing capacity while continuing discussions with regional partners, including Brazil’s Fiocruz, to strengthen future supply in Latin America. The company expects to provide initial supplies of alimatravir following potential regulatory approval until licensed manufacturers complete product development and regulatory authorization.

Implementation will depend on regulatory decisions in participating countries, with early licensing designed to accelerate readiness once approvals are granted. Merck also plans to ensure continued access for participants enrolled in the ongoing EXPrESSIVE Phase 3 trials after study completion, subject to regulatory approval.

If approved following successful Phase 3 development, alimatravir could become the first once-monthly oral PrEP option, complementing existing daily oral and long-acting injectable regimens while expanding HIV prevention choices worldwide.

Reference

Merck Announces Initial Access Plans for Alimatravir, an Investigational Once-Monthly Oral HIV Pre-Exposure Prophylaxis in Phase 3 Development – Merck.com