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Merck Dumps COVID Vaccine Program After Poor Immune Response in Early Trials

Merck said it will discontinue its coronavirus vaccine program, while continuing its focus on therapies, following poor immune responses from patients in early-stage trials.

Merck & Co.  (MRK) - Get Merck & Company Inc. Report halted its nascent coronavirus vaccine development program Monday citing 'inferior immune response' compared to those developed by rivals.

Merck said the decision followed data from a Phase 1 trial of its V590 and V591 vaccine candidates, which showed immune responses that were inferior to those seen in patients who were infected naturally, as well as those dosed by other COVID-19 vaccines. Merck said it will continue to develop its other coronavirus therapies, including its MK-7110, which received Emergency Use Authorization approval from the Food & Drug Administration late last year.

“We are grateful to our collaborators who worked with us on these vaccine candidates and to the volunteers in the trials,” said Merck Research Laboratories president Dr. Dean Y. Li. "We are resolute in our commitment to contribute to the global effort to relieve the burden of this pandemic on patients, health care systems and communities.”  

Merck shares were marked 0.8% lower in early trading following the vaccine program news to change hands at $80.32 each. 

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Merck acquired the MK 7110 treatment in November through its $425 million takeover of Rockville, Maryland-based Oncolmmune, which said its developing therapy can sharply reduce the risk of death or respiratory failure in patients suffering from severe forms of COVID-19. 

The deal would pay Merck around $356 million for the manufacture and supply of between 60,000 and 100,000 doses of MK-7110 by then end of June, the company said. Merck said the agreement would allow for the development, manufacture and distribution of the treatment.