More than 170 patient advocacy groups spanning 30 countries are urging pharmaceutical company Merck to proactively develop a global access strategy for its investigational HIV prevention pill, MK-8527, even as the drug remains under clinical study. The preemptive call to action underscores the potential impact of this new preventative measure and the importance of equitable distribution should it prove successful.
MK-8527 is being studied as a once-monthly oral preventative for HIV, a significant improvement over current daily oral pre-exposure prophylaxis (PrEP) regimens. The convenience of a monthly dose is expected to improve adherence, a known challenge with daily PrEP, particularly in resource-limited settings. A key, late-stage study evaluating the pill’s efficacy is not anticipated to conclude until .
The advocacy groups, in a letter to Merck CEO Robert M. Davis, emphasized that the pill “represents a potentially transformative addition to the HIV prevention toolkit — a convenient monthly oral option that could address the adherence challenges that have limited the impact of daily oral [prevention pills], particularly in low-income and middle-income countries where the vast majority of the 1.3 million people who acquire HIV each year reside.”
The need for new PrEP options is underscored by the ongoing global HIV epidemic. According to UNAIDS, 1.3 million people acquired HIV in , highlighting the continued vulnerability and the demand for effective prevention strategies. Current PrEP options, while effective, require consistent daily adherence, which can be difficult for some individuals to maintain.
Merck initiated Phase 3 clinical trials for MK-8527 in , in collaboration with the Gates Foundation. The trials, known as EXPrESSIVE-10 and EXPrESSIVE-11, are designed to evaluate the safety and efficacy of the drug in different populations. EXPrESSIVE-11 (MK-8527-011, NCT 07044297) will focus on individuals with a higher likelihood of HIV-1 exposure across 16 countries. EXPrESSIVE-10 (MK-8527-010) will specifically evaluate the drug’s effectiveness in women and adolescent girls in sub-Saharan Africa, a region disproportionately affected by HIV.
The development of MK-8527 builds on recent advancements in HIV prevention. The recent US approval of lenacapavir, a twice-yearly injectable PrEP, has generated excitement in the field. However, oral medications like MK-8527 may offer advantages in terms of global rollout, as they do not require administration by a healthcare provider. Injectable medications also aren’t suitable for everyone, with some individuals expressing discomfort with needles or preferring the simplicity of a pill.
Data from surveys indicate a preference for monthly oral PrEP among some populations. A survey of men who have sex with men in the US, for example, showed a preference for a monthly pill compared to currently available options. This preference highlights the potential for improved adherence and broader acceptance with a more convenient dosing schedule.
MK-8527 is a nucleoside reverse transcriptase translocation inhibitor (NRTTI). Phase 2 trial results, which supported the initiation of the Phase 3 program, demonstrated favorable pharmacokinetics and a good safety profile. Pharmacokinetics refers to how the drug is processed and used by the body, including absorption, metabolism, distribution, and elimination. These early findings suggest that the drug is well-tolerated and effectively distributed within the body.
The advocacy groups’ call for a global access strategy reflects a growing awareness of the need to ensure that new HIV prevention technologies are available to those who need them most. Historically, access to essential medicines has been unevenly distributed, with low- and middle-income countries often facing delays and barriers to access. A proactive strategy from Merck could help to mitigate these challenges and ensure that MK-8527 reaches the populations most at risk of HIV infection.
The ongoing research and development of new HIV prevention tools, including MK-8527 and long-acting injectables, represent significant progress in the fight against the epidemic. However, sustained investment, equitable access, and continued innovation will be crucial to achieving the goal of ending HIV as a public health threat.
