Even with the HIV prevention waters now dominated by Gilead Science’s Yeztugo (lenacapavir), Merck & Co. is not afraid to swim deeper in. The New Jersey pharma is teaming up with the Gates Foundation to launch a pair of phase 3 trials of its once-monthly, oral pre-exposure prophylaxis (PrEP) prospect.
The EXPrESSIVE-10 trial will begin enrolling women and girls across 31 sites in Kenya, South Africa and Uganda within the next few months, Merck said in a July 14 release. Another trial, EXPrESSIVE-11, will start enrolling sexually active people from 16 countries in August. Both trials aim to enroll around 4,400 people and will test whether Merck’s MK-8527 reduces the incidence of HIV compared to Gilead’s daily PrEP pill Truvada (emtricitabine/tenofovir).
The Gates Foundation is providing grant funding to the International Clinical Research Center (ICRC) at the University of Washington and the University of Alabama at Birmingham to support EXPrESSIVE-10, according to the release, with the money going towards a community advisory group, patient recruitment and retention materials, while also supporting ICRC’s partnership with the trial sites.
The nonprofit is also providing funds for a community advisory group, patient recruitment and retention materials for EXPrESSIVE-11.
MK-8527 inhibits the reverse transcriptase enzyme that HIV uses to replicate, according to the release. The Big Pharma recently wrapped up a phase 2 trial of the asset, which revealed similar rates of adverse events between the treatment and placebo arms. The company plans to share more data from the study at the AIDS Society Conference on HIV Science in Rwanda on July 16.
The public health world has been abuzz about Gilead’s twice-yearly lenacapavir injection, which was approved as Yeztugo on June 19 and has been hailed as a scientific breakthrough. An HIV physician told Mizuho Securities that she expects most of her patients to switch to Yeztugo within the next year, with the pharma projecting a peak sales potential of $8 billion per year for the drug.
For MK-8527, Merck is betting that there will be a robust market of people seeking PrEP who prefer oral meds to needles.
“Scientific advances against HIV have brought us further than ever imagined and are ushering in a new era in HIV prevention,” Trevor Mundel, Ph.D., president of global health at the Gates Foundation, said in the release. “With only 18% of global PrEP need currently met, there is a clear and urgent need for options like MK-8527 that may offer the ability to prevent infection. These phase 3 trials are a key step toward translating progress into longer-acting options that could help turn the tide on HIV.”
The World Health Organization updated its HIV prevention guidelines on July 14 to recommend Yeztugo, with Director-General Tedros Adhanom Ghebreyesus, Ph.D., calling lenacapavir the “next best thing” in the absence of an HIV vaccine.