Merck to end development of Covid-19 vaccines, cites inferior immune responses

U.S Drugmaker Merck & Co has said it will end development of its two Covid-19 vaccines, and will focus pandemic research on treatments.

In a statement released on Monday, the multinational pharmaceutical company said it will record a pretax discontinuation charge in the fourth quarter for vaccine candidate V591, which it acquired with the purchase of Austrian vaccine maker Themis Bioscience, and V590, developed with nonprofit research organization IAVI.

The pharmaceutical company was late to join the race to develop a vaccine to protect against the coronavirus, which has so far killed more than 2 million people and continues to surge in many parts of the world including the United States.

In early trials, both vaccines generated immune responses that were inferior to those seen in people who had recovered from COVID-19 as well as those reported for other COVID-19 vaccines, the company said.

Merck said it will focus COVID-19 research and manufacturing efforts on two investigational medicines: MK-7110 and MK-4482, which it now calls molnupiravir.

Molnupiravir, which is being developed in collaboration with Ridgeback Bio, is an oral antiviral being studied in both hospital and outpatient settings.
The company added that a phase 2/3 trial of the drug is set to finish in May, but initial efficacy results are due in the first quarter and will be made public if clinically meaningful.