Merck received provisional test results this month.
Merck & Co. is halting the development of its two Covid-19 experimental vaccines after the first test data showed that they failed to generate immune responses comparable to a natural infection or existing vaccines.
The American pharmaceutical giant, which has a long history of successful vaccine development, has adopted a different strategy from rivals Pfizer Inc., Moderna Inc. and Johnson & Johnson, using a more traditional approach to focus on weakened virus-based vaccines. One, called V590, borrowed Ebola inoculation technology from Merck, while the other, V591, is based on a measles vaccine used in Europe.
Both V590 and V591 were lagging behind in the race to develop the vaccine. Merck finished recruiting the first participants for early-stage security studies towards the end of 2020, when major competitors Pfizer and Moderna were preparing to report final stage data on the effectiveness of their shots. Merck received provisional test results this month.
The results were “disappointing and somewhat surprising,” said Nick Kartsonis, senior vice president of clinical research for infectious diseases and vaccines at Merck Research Laboratories. Both injections generated less neutralizing antibodies to stop infection than other Covid-19 vaccines and produced lower immune responses compared to people who contracted the coronavirus naturally.
“We didn’t have what we needed to move on,” said Kartsonis in an interview on Sunday. After evaluating the data, Merck’s senior leadership decided to discontinue the programs and divert resources to the company’s efforts to develop Covid-19 treatments.
Vaccine anxiety
Although Merck’s vaccines were not expected to be part of the initial boost in immunization in the United States, development occurs amid heightened anxiety about the supply of vaccines and a slow rate of injections. The emergence of new variants of the coronavirus also raised doubts about whether the injections that were eliminated will lose their effectiveness with the mutation of the pathogen.
The failure of Merck’s candidates will also leave it out of a market that could be dominated by two of its historic rivals in the United States. Pfizer was the first pharmacist to obtain authorization for a Covid vaccine in the U.S., closely followed by Moderna, and in the coming weeks, Johnson & Johnson is expected to publish data on the effectiveness of its vaccine and apply for an emergency use authorization.
None of Merck’s candidates were among the six primary vaccines in the US government’s Operation Warp Speed portfolio, although its leadership closely watched them. The drugmaker and its partner International AIDS Vaccine Initiative (IAVI) have received some funding for government research. Both candidates would be single-shot shots.
Merck, based in Kenilworth, NJ, will file a pre-tax charge for the fourth quarter of 2020 for costs related to program suspension. He did not disclose the amount of the charge on Monday. The results of the trial at an early stage will be submitted to a peer-reviewed medical journal.
Two coronavirus vaccines have been released for use in the United States, but a steady increase in infections has highlighted the need for more treatment options. Merck will direct resources to two drugs at an advanced stage of development to fight the disease, according to Kartsonis.
“In the world of pharmaceutical development, rapid elimination is not a bad thing because it allows you to reposition and redirect your assets,” he said.
Several of Merck’s vaccine manufacturing facilities are being redesigned to produce one of its Covid-19 drug candidates, MK-7110, which is complex and difficult to manufacture on a large scale. In an intermediate study, intravenous therapy significantly improved the likelihood and speed of recovery for critically ill and critical patients with Covid-19 who need oxygen, reducing the risks of respiratory failure and death by more than 50%. The full results of the study are expected in the first quarter.
Merck executives expect U.S. regulators to grant an emergency use authorization for the drug after these results, and Kartsonis said it could reach sick patients by mid-year. The US has already agreed to pay $ 365 million for 60,000 to 100,000 doses.
Antiviral pill
Merck is also working on a pill for patients with Covid-19 in the early stages of the disease. Known as molnupiravir, antiviral therapy was discovered by scientists at Emory University and is being studied in final stage tests in hospitals and outpatient clinics. Merck and partner Ridgeback Biotherapeutics LP hope to have initial data on the drug’s effectiveness in the first quarter and complete studies in May, the company said in a statement.
Marketing director Michael Nally said in December that Merck expects a regulatory release soon after the company’s data, if successful.
The antiviral should be taken twice daily for five days, for a total of ten capsules. Merck predicts it will be able to produce more than 20 million courses of treatment, or 200 million capsules, in 2021, said Nally.
The slow release of the vaccine shows that the need for therapy will persist, said Kartsonis, and the drugs may work against future viruses.
(Except for the title, this story was not edited by the NDTV team and is published from a syndicated feed.)