Merck to Focus on COVID-19 Therapeutics After Scrapping Its Coronavirus Vaccine Programs

In a surprise move, Merck announced that it is giving up on its two coronavirus vaccine candidates after seeing a subpar immune response and shifting its focus to a pair of investigational coronavirus treatments.

The pharma titan said it will continue its work on clinical trials and manufacturing scale-up for two investigational coronavirus meds, MK-7110 and MK-4482, the latter of which is being developed in collaboration with Ridgeback Bio.

MK-4482 (molnupiravir), an experimental antiviral first developed for treating influenza, is currently being evaluated as a COVID-19 treatment in phase 2/3 trials. Initial efficacy data are anticipated in the first quarter and the phase 2/3 trials are expected to wrap up in May.

MK-7110, previously known as CD24Fc, is a recombinant fusion protein that controls the body’s inflammatory response. Merck obtained the potential COVID-19 treatment in its $425 million acquisition of OncoImmune (DID, Nov. 24, 2020).

It has shown promise so far, with interim results from a phase 3 trial demonstrating the drug provided a more than 50 percent reduction in the risk of death or respiratory failure in patients hospitalized with moderate-to-severe COVID-19 infections. The full results of the trial are expected in the first quarter, and the company last month hashed out a $356 million supply agreement with the U.S. government for up to 100,000 doses (DID, Dec. 28, 2020).

Merck’s move to drop its two COVID-19 vaccine candidates, which it made after phase 1 trial findings showed they were well-tolerated but didn’t generate strong enough immune responses, is disappointing and surprising given its position as a vaccine powerhouse. The company manufactures vaccines for 11 of the 17 diseases on the Centers for Disease Control and Prevention’s (CDC) list of recommended immunizations and it distributed 190 million vaccine shots around the world in 2019.

The drugmaker’s decision coincides with a tightening of vaccine supplies in the U.S. and around the globe. Pfizer/BioNTech and AstraZeneca have all announced delays as countries continue to clamor for additional shots. It’s hoped that Johnson & Johnson’s single-dose vaccine will prove to be safe and effective in the interim results of its late-stage trial, expected soon, so that it may be authorized and help relieve some of the burdens of vaccine supply and distribution. — James Miessler