Merck discontinues development of COVID-19 vaccine candidates

Jan. 25, 2021

Merck announced that the company is discontinuing development of its SARS-CoV-2/COVID-19 vaccine candidates, V590 and V591, and plans to focus its SARS-CoV-2/COVID-19 research strategy and production capabilities on advancing two therapeutic candidates, MK-4482 and MK-7110, according to a news release from the company.

Merck said its decision follows the company’s review of findings from Phase 1 clinical studies for the vaccines. In these studies, both V590 and V591 were generally well tolerated, but the immune responses were inferior to those seen following natural infection and those reported for other SARS-CoV-2/COVID-19 vaccines. Merck continues to advance clinical programs and to scale-up manufacturing for two investigational medicines, MK-7110 and MK-4482 (molnupiravir); molnupiravir is being developed in collaboration with Ridgeback Bio.

Merck said the company and its collaborators plan to submit the results of the Phase 1 studies for V590 and V591 for publication in a peer-reviewed journal. Merck will also continue to evaluate the potential of the measles-virus vector and vesicular stomatitis virus vector-based platforms and pursue broader pandemic-response capabilities.

As far as therapeutics for COVID-19, Merck is developing the following interventions:

· MK-7110 (formerly CD24Fc), an investigational recombinant fusion protein that modulates the inflammatory response to SARS-CoV-2, principally by targeting a novel immune pathway checkpoint. Interim results from a Phase 3 study showed a greater than 50 percent reduction in the risk of death or respiratory failure in patients hospitalized with moderate to severe COVID-19. Full results from this study are expected in the first quarter of 2021. In December, Merck announced a supply agreement with the U.S. government to advance the manufacturing and initial distribution of MK-7110.

· Molnupiravir (MK-4482), an oral novel investigational antiviral agent being developed in collaboration with Ridgeback Bio. Molnupiravir is currently being evaluated in Phase 2/3 clinical trials in both the hospital and outpatient settings. The primary completion date for the Phase 2/3 studies is May 2021.

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