WHO OKs molnupiravir as treatment for Covid-19, after new data from India
The WHO updated its guidelines on Wednesday to recommend molnupiravir, Merck’s antiviral pill, for treating patients newly diagnosed with Covid-19.
It’s the first Covid-19 pill recommended by the WHO, coming before any recommendation around Pfizer’s Paxlovid, despite continued questions about the precise magnitude of benefit and the risks associated with the Merck drug.
The new decision, however, comes after a trial in India on a generic version of molnupiravir found the pill reduced the risk of hospitalization from Covid-19 by 65%. Although not conclusive, it was another data point in the ongoing debate over molnupiravir’s efficacy. Merck’s initial data showed the pill cut the risk of hospitalization among high-risk Covid-19 patients in half, but later analyses of the same trial cut that number to just 30% — a drop the company struggled to explain to the FDA.
Lab studies show the efficacy should be unaffected by new variants such as Omicron.
WHO nodded to those risks in its statement, addressing them in a similar fashion to how US health agencies addressed them. The global health body said the drug should be prescribed only for patients with the “highest risk of hospitalization,” such as the unvaccinated, the immunocompromised, older adults and people with chronic conditions.
And, like the FDA, they advised against prescribing it in pregnant women. That’s because of the drug’s mechanism of action — it induces a lethal number of mutations in the coronavirus genome — and it could also induce mutations in humans. Some lab studies suggest it’s possible, although the exact risk to patients who take the pill for just the recommended five days remains unknown and Merck has presented evidence to suggest it’s minimal.
Merck has taken steps to make the drug available globally, signing licenses with generic drugmakers in India and striking an agreement with the Medicines Patent Pool, a UN-backed nonprofit that will work to make the pill available in 105 low- and middle-income countries.
Criticism of the drug has not abated, though. On Thursday, James Brophy, a professor of medicine at McGill University, published an op-ed in the British Medical Journal questioning the UK’s decision to authorize the drug and pointing to the safety concerns and lingering questions over its exact efficacy.
These questions have affected uptake in the US. Even as Omicron surged in the US, molnupiravir sat on shelves at many pharmacies across the country. In February, the Financial Times reported that the EMA might deny authorization for the pill over those concerns.
