Merck’s COVID pill shows lower efficacy in updated study

Drugmaker Merck’s experimental COVID-19 pill is significantly less effective in slashing hospitalisations and deaths than previously reported, the company has said, following the release of a full analysis of trial results.

The United States-based firm said on Friday the oral drug, molnupiravir, showed a 30 percent reduction in hospitalisations and deaths when compared with a placebo, based on data from more than 1,400 patients.

Last month, the company said data from 775 patients had showed that reduction was “approximately” 50 percent.

In the updated data, one death was reported in the molnupiravir arm of the study, versus nine in the placebo group.

Merck filed for a US authorisation of molnupiravir on October 11, following the interim data.

The release of the full analysis came before the US Food and Drug Administration (FDA) published a set of documents on Friday intended to brief a panel of outside experts who are due to meet on Tuesday to discuss whether to recommend authorising the pill.

The agency’s staff did not make their own recommendation as to whether the pill should be approved.

FDA staff asked the panel to discuss whether the benefits of the drug outweigh the risks and whether the population for whom the drug should be authorised should be limited.

They also asked the committee to weigh in on concerns over whether the drug could encourage the virus to mutate, and how those concerns could be mitigated.

Merck’s shares dropped nearly 3 percent to $80 in premarket trading amid an overall fall in the stock market due to news of a new coronavirus variant.

Pills such as molnupiravir and paxlovid, a rival drug being developed by Pfizer, have been touted as potential game-changers as they can be taken as early home treatments to help prevent hospitalisations and deaths.

Data from Pfizer’s pill, following analysis of a study involving 1,200 participants, showed an 89 percent reduction in the risk of coronavirus-related hospitalisations or deaths compared with a placebo.

The two experimental drugs have different mechanisms of action. Merck’s is designed to introduce errors into the genetic code of the virus. Pfizer’s drug, part of a class known as protease inhibitors, is designed to block an enzyme the coronavirus needs to multiply.

Last week, the European Union’s medicines watchdog advised its member states they can use Merck’s COVID-19 antiviral pill in emergency situations triggered by rising infection rates, ahead of the treatment’s formal approval across the bloc.

The United Kingdom conditionally approved molnupiravir, branded as Lagevrio, earlier this month.