Two drugmakers in the country have requested permission to end their late-stage trials on Merck & Co's experimental antiviral drug molnupiravir in moderate COVID-19 patients.
The two drugmakers, Aurobindo Pharma Ltd and MSN Laboratories plan to continue late-stage trails of the drug for those with mild COVID-19, the drug regulator's expert committee said on Friday.
The two companies separately sought permission to end trials in the case of moderate COVID-19 patients after having submitted interim clinical trial data around the effectiveness of the drug in treating this category of patients, the committee disclosed, throwing into question the efficacy of the experimental drug in improving outcomes for patients with moderate cases of COVID-19.
Separately, a source at the drug regulator told Reuters that molnupiravir had shown no "significant efficacy" against moderate COVID-19 cases
Shares in Merck soared last week after it and partner Ridgeback Biotherapeutics said an interim analysis of a late-stage clinical trial on molnupiravir showed the medicine nearly halved the risk of hospitalisation or death for patients with mild or moderate COVID-19.
It was not immediately clear whether the drugmakers and Merck used identical criteria to define moderate COVID-19 cases.
Aurobindo Pharma, MSN and Merck did not immediately reply to Reuters' requests for comment.
Merck has entered into voluntary licensing agreements with at least eight Indian drugmakers for molnupiravir, with an aim to turn the country into a manufacturing hub for the drug to supply low- and middle-income nations.
Aurobindo Pharma has been conducting a clinical trial on the drug in 100 patients with moderate COVID-19 since August this year
According to its trial details, moderate patients included those with fever, coughing, breathing difficulties and oxygen deficiency.
Of the eight Indian firms, five - Dr Reddy's Laboratories, Cipla, Sun Pharma, Torrent Pharmaceuticals and Emcure Pharmaceuticals - are conducting a joint trial for the antiviral drug only in mild COVID-19 patients in an outpatient setting
The other licenced company, Hetero, in early July announced interim data from its own late-stage trial in treating mild COVID-19 patients and submitted an application for emergency use approval for the same
Hetero is separately conducting a study on moderate COVID-19 patients and it has said clinical results on the same will be shared in due course.