Once-monthly oral HIV PrEP: MSD partners with Aspen for LMIC access

MSD includes Aspen, a South African manufacturer, in early access plans for its investigational monthly HIV prevention pill under a voluntary licensing strategy covering 129 low- and middle-income countries.

MSD, known as Merck in the United States and Canada, has announced early plans to support rapid and sustainable access to alimatravir. This is an investigational once-monthly oral pre-exposure prophylaxis medicine being evaluated for the prevention of HIV-1.

The announcement comes as an estimated 1.2 million people acquired HIV globally in 2025 – approximately 3 300 people each day. Only 3.5 million people were using oral PrEP in 2023, against a global target of 20 million by 2030.

Subject to successful clinical trials and regulatory approval, MSD’s strategy includes a royalty-free, non-exclusive voluntary licensing agreement with Aspen Pharmacare. Aspen is among seven generic manufacturers selected to support future supply across 129 low- and middle-income countries.

Voluntary licensing and access strategy

“Recognising 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,” said Robert Davis, chairman and chief executive officer of Merck.

Three of the manufacturers are based in sub-Saharan Africa, marking the first time manufacturers in the region have been included in the initial voluntary licensing process for an HIV prevention medicine.

“People across Africa need more options to prevent HIV. A once-monthly pill could provide a different choice for people in how to protect themselves, subject to successful trials and regulatory approval,” said Jean Kaseya, director-general of the Africa Centres for Disease Control and Prevention. “We welcome this decision to engage African manufacturers early.”

South Africa is also participating in EXPrESSIVE-10, an ongoing Phase 3 trial evaluating alimatravir among adolescent girls and young women in South Africa, Kenya and Uganda. Alimatravir remains investigational and has not been approved for use. MSD has committed to supporting access for trial participants after the studies conclude, subject to regulatory approval.

For an overview of Merck’s HIV treatment and prevention clinical development programme, click here.