New Analysis Shows Merck’s COVID-19 Antiviral Treatment Has Lower Efficacy

A new analysis of clinical trial results shows that Merck’s antiviral pill for treating COVID-19 is significantly less effective than previously reported in October, the company announced on Friday.

In the updated report, the drugmaker said its antiviral treatment drug, which is called molnupiravir, showed a 30 percent reduction in hospitalizations and deaths from the CCP (Chinese Communist Party) virus, based on data from 1,433 patients.

In the company’s full analysis, one patient died in the molnupiravir group, and nine in the placebo group. The molnupiravir arm of the study had a hospitalization and death rate of 6.8 percent. The placebo group had a hospitalization and death rate of 9.7 percent.

In early October, the drugmaker announced in its interim analysis of a phase 3 trial studying the treatment that the pill is able to cut the risk of hospitalization or death in half for adults who were deemed at risk but not hospitalized.

Compared to the 14.1 percent of patients who received placebos, 7.3 percent of trial participants who received the drug were hospitalized through day 29, the company and its partner Ridgeback Biotherapeutics said at the time. Eight people died in the placebo group while nobody did in the group given molnupiravir.

The lower efficacy of Merck’s drug could have big implications in terms of whether countries continue to buy the pill.

In mid-October, Merck and its partner sought authorization with the U.S. Food and Drug Administration (FDA) for their oral antiviral medicine.

On Friday, the FDA posted its review of Merck’s experimental COVID-19 pill ahead of a public meeting next week when outside experts will debate the drug’s benefits and risks, The Associated Press reported. American health officials said the pill is effective, but they raised questions about its safety during pregnancy.

The FDA will ask its experts whether the drug’s benefits outweigh its risks for various patient groups, including pregnant women.

Antiviral treatments, just like Pfizer Inc’s experimental drug called PAXLOVID, need to be given to patients as early as possible to be most effective, best within days of the onset of symptoms.

pfizer-pill
Paxlovid, a Pfizer COVID-19 pill, is seen manufactured in Ascoli, Italy, in this undated photo obtained by Reuters on Nov. 16, 2021. (Pfizer/Handout via Reuters)

Merck and Pfizer’s treatments are cheaper to produce and easier to administer than existing options such as antibody therapies from Regeneron and Eli Lilly, which are mostly administered as intravenous infusions.

U.S.-based Pfizer Inc. announced in early November its oral antiviral treatment “significantly” reduces the risk of hospitalization and death for high-risk patients. According to a company press release published on Nov. 5, the pill was found in a scheduled interim analysis to reduce the risk of hospitalization or death from the CCP virus by 89 percent if the patient receives the drug in time.

President Joe Biden said at the time Pfizer released its analysis that the United States has already secured millions of doses of the experimental antiviral pill.

“If authorized by the FDA we may soon have pills that treat the virus in those who become infected,” Biden said. “We’ve already secured millions of doses. The therapy would be another tool in our toolbox to protect people from the worst outcomes of COVID.”

Currently, the only COVID-19 antiviral treatment granted an emergency use authorization by the FDA is remdesivir, which is being sold under the brand name Veklury.

The treatment involves combining remdesivir with the anti-inflammatory oral drug baricitinib for patients 2 years of age or older who need supplemental oxygen, invasive mechanical ventilation, or extracorporeal membrane oxygenation (ECMO), according to the FDA.

Reuters contributed to this report.