EMA starts rolling review of Merck's molnupiravir, continuing rapid regulatory response to COVID-19 antiviral data

Merck
The start of the rolling review could open the door to Merck striking a deal to supply molnupiravir to the EU. (Merck & Co.)

Merck has opened another front in its campaign to get molnupiravir to market, kicking off a process that could lead to the approval of the oral COVID-19 antiviral in the EU.

Things have moved quickly since Merck and partner Ridgeback Biotherapeutics posted top-line data on molnupiravir in patients with mild to moderate COVID-19 at the start of the month. Merck got an application for approval to the FDA 10 days after reporting the data. Now, another two weeks down the line, the European Medicines Agency (EMA) has begun a rolling review of molnupiravir.

The EMA will use the rolling review to assess quality, safety and effectiveness data as they become available, continuing until Merck has enough evidence to file a marketing authorization application. It is unclear how long the rolling review or final assessment will take.

Merck is seeking approval on the strength of data on 762 COVID-19 patients at high risk of disease progression. Of the patients who received molnupiravir 800 mg twice a day, 7.3% were hospitalized. The rate of hospitalization and death in the placebo cohort was 14.1%. All eight deaths happened in the placebo group.

RELATED: Merck makes beeline to FDA, seeking approval for COVID-19 antiviral 10 days after reporting data

Safety looks clean based on the very limited data shared so far by Merck but is likely to be a focus of regulatory reviews, given molnupiravir has a novel mechanism of action that drives viral mutations. A study found the initial metabolite of molnupiravir is mutagenic to mammalian cells, creating the potential for long-term genotoxic side effects.

The start of the rolling review could open the door to Merck striking a deal to supply molnupiravir to the EU. Earlier this month, Reuters reported the EU would only consider striking a deal with Merck to supply molnupiravir to member states once the approval process was underway. 

Other countries have already secured supplies. The U.S. put in a $1.2 billion order for 1.7 million courses of molnupiravir over the summer. Last week, the U.K. government disclosed its own deal, revealing it has bagged 480,000 courses of molnupiravir and 250,000 courses of Pfizer’s rival antiviral ritonavir.