Merck Shares Access Strategy for Investigational Monthly PrEP Alimatravir

Merck announced early components of a multifaceted strategy to provide rapid, broad, and sustainable access to alimatravir (MK-8527) in low- and middle-income countries (LMICs), following regulatory approval. Alimatravir is an investigational, novel, once-monthly oral pill being developed as pre-exposure prophylaxis (PrEP) for the prevention of HIV-1.¹

The announcement comes as 2 phase 3 trials of the drug continue enrolling participants and ahead of the international AIDS conference where global HIV prevention priorities will be discussed.

Early Licensing Agreements Cover 129 Countries

Merck signed 7 nonexclusive voluntary licensing agreements with generic manufacturers, including 3 in sub-Saharan Africa (Aspen Pharmacare Holdings, Ltd; Quality Chemical Industries Limited; and UCL Kenya) and 4 in India (Aurobindo, Cipla, Emcure, and Viatris). The royalty-free agreements cover both public and private sectors and are intended to enable generic supply of alimatravir in 129 LMICs that account for a substantial majority of new HIV diagnoses worldwide, if the drug is approved.¹

Establishing these agreements before phase 3 enrollment is complete marks a first for HIV prevention drug development, according to Merck. The company said the early action is designed to help stakeholders across the HIV response begin planning for scale-up and to accelerate developmental and regulatory work by licensed generic manufacturers.¹

“Scientific innovation only has impact when it reaches those who need it most,” Robert M. Davis, chairman and chief executive officer of Merck, said in a news release.¹ “Recognizing the urgent, unmet needs in HIV prevention, we are acting early to enable rapid, broad, and sustainable access to alimatravir, an investigational once-monthly oral PrEP option, in low- and middle-income countries.”

This is also the first time generic manufacturers in sub-Saharan Africa have been included in initial voluntary licenses for an HIV drug, alongside manufacturers in India.¹

“People across Africa need more options to prevent HIV,” Jean Kaseya, director general of the Africa Centres for Disease Control and Prevention, said in the release.¹ “We welcome this decision to engage African manufacturers early.”

About Alimatravir and Its Mechanism

Alimatravir inhibits reverse transcriptase through 2 mechanisms: inhibition of reverse transcriptase translocation, which results in immediate chain termination, and induction of structural changes in viral DNA, which causes delayed chain termination. If approved, the once-monthly pill is predicted to be protective starting within 1 hour after dosing.¹

Alimatravir is being evaluated in 2 ongoing phase 3 trials. The EXPrESSIVE-10 trial (MK-8527-010, NCT07071623), supported financially by the Gates Foundation, is evaluating safety and efficacy in adolescent girls and young women in Kenya, South Africa, and Uganda. Additionally, the EXPrESSIVE-11 trial (MK-8527-011, NCT07044297) is evaluating safety and efficacy among people with greater likelihood of HIV-1 exposure across 16 countries. Both trials are currently enrolling.¹

The phase 3 program was supported by results from a phase 2 trial (MK-8527-007, NCT06045507) that enrolled 350 participants with low likelihood of HIV-1 exposure, randomized to receive alimatravir (3 mg, 6 mg, or 12 mg) or placebo once monthly for 6 months. Adverse event rates were similar between alimatravir and placebo arms, and no clinically meaningful changes were observed in laboratory tests, including total lymphocyte and CD4 T-cell counts.¹

Part of a Broader Shift Toward Less Frequent Oral Regimens

Merck's access planning for alimatravir arrives alongside separate news on the treatment side of its HIV portfolio. Gilead Sciences and Merck recently reported detailed week 48 results from the phase 3 ISLEND-1 (NCT06630286) and ISLEND-2 (NCT06630299) trials evaluating a once-weekly oral single-tablet regimen combining islatravir 2 mg and lenacapavir 300 mg (ISL/LEN) in adults with virologically suppressed HIV.²

In the double-blind ISLEND-1 trial, no participants (0%) who switched to ISL/LEN had HIV-1 RNA of 50 copies/mL or higher at week 48, compared with 0.3% of those who remained on bictegravir/emtricitabine/tenofovir alafenamide. In the open-label ISLEND-2 trial, 0.3% of ISL/LEN participants met that threshold versus 1.3% of those on standard-of-care regimens; both trials met noninferiority thresholds.²

Participants who switched to ISL/LEN also reported higher treatment satisfaction and lower treatment burden than those who remained on daily standard-of-care therapy.² Together with alimatravir's monthly PrEP profile, the once-weekly treatment data reflect an industry-wide movement toward extending dosing intervals across both HIV prevention and treatment, a shift that carries direct implications for pharmacy practice.

The Pharmacist's Expanding Role in HIV Prevention

Pharmacists already occupy a central position in HIV prevention and care delivery, and that role is likely to grow as longer-interval oral options move toward approval. Pharmacists provide PrEP services for people at high risk of HIV through collaborative practice agreements with medical providers, and pharmacist-led PrEP clinics are already operational in several states, spanning community pharmacies, ambulatory care clinics, and telemedicine settings.³

Pharmacists' roles in PrEP delivery include identifying at-risk patients, initiating PrEP where permitted by state regulations, helping patients address barriers to adherence, ordering laboratory results, and providing follow-up care.³

Beyond PrEP, pharmacists support medication adherence more broadly through one-on-one counseling, reminder tools, adherence packaging, and medication therapy management, interventions shown to improve viral suppression rates among people with HIV.³

Because more than 90% of people in urban areas of the United States live within 2 miles of a pharmacy, pharmacists are especially well positioned to expand access to HIV services in communities with limited access to traditional health care settings.^3,4

As HIV.gov has noted, pharmacists are increasingly serving as trusted bridges to doctors, clinics, and public health programs and, in some areas, can now prescribe PrEP and post-exposure prophylaxis directly.⁴

If alimatravir and the once-weekly ISL/LEN regimen are ultimately approved, pharmacists will likely play an increasing role in counseling patients on adherence expectations, monitoring schedules, and the tradeoffs between daily, weekly, and monthly options, an area of practice already supported by existing collaborative practice frameworks.^3,4

REFERENCES

1. Merck announces initial access plans for alimatravir, an investigational once-monthly oral HIV pre-exposure prophylaxis in phase 3 development. News release. Merck & Co Inc. July 24, 2026. Accessed July 28, 2026. https://www.merck.com/news/merck-announces-initial-access-plans-for-alimatravir-an-investigational-once-monthly-oral-hiv-pre-exposure-prophylaxis-in-phase-3-development/

2. Gallagher A. Once weekly oral HIV regimen maintains suppression through week 48. Drug Topics. July 22, 2026. Accessed July 28, 2026. https://www.drugtopics.com/view/once-weekly-oral-hiv-regimen-maintains-suppression-through-week-48

3. McCree DH, Byrd KK, Johnston M, Gaines M, Weidle PJ. Roles for pharmacists in the "Ending the HIV Epidemic: A Plan for America" initiative. Public Health Rep. 2020;135(5):547-554. doi:10.1177/0033354920941184

4. HIV.gov. Caring for communities: pharmacists' role in HIV care and prevention. HIV.gov. February 9, 2026. Accessed July 28, 2026. https://www.hiv.gov/blog/caring-for-communities-pharmacists-role-in-hiv-care-and-prevention