Covid-19 pill promises in preliminary tests

Additional studies of the experimental antiviral are underway. If able to treat people with Covid-19 who have symptoms, the drug would reinforce a limited arsenal of treatments and would be the first oral antiviral against the disease.

After more than a year of the pandemic, doctors and patients at Covid-19 have few options. Only one antiviral has been authorized for use: remdesivir from Gilead Sciences Inc.

, and has been shown to provide only a modest benefit to hospitalized patients, reducing their stays by several days.

The experimental drug, called molnupiravir, could play an important role in helping people who are sick, but still at home, playing the same role that Tamiflu played for flu, say some infectious disease experts.

“It’s tempting and interesting, but it’s not exactly 100% complete,” said Carl Dieffenbach, director of the AIDS Division at the National Institute of Allergy and Infectious Diseases, who was not involved in the study. “What we need to confirm is that there is a clinical benefit.”

Drug researchers are making an effort to find new Covid-19 drugs to improve the performance of the few therapies currently available and fill the gaps in offerings. They are also looking for therapies that are effective against new variants of the coronavirus that are spreading rapidly.

“The clear need for this is the development of potent antivirals that act directly on SARS-CoV-2,” said Anthony Fauci, director of NIAID and chief medical advisor to President Biden, in a recent White House briefing, referring to to the virus that causes the pandemic.

Unlike other drugs that target the spike protein that protrudes from the virus’s surface, molnupiravir attacks a part of the virus that helps it reproduce.

The intermediate-stage or Phase 2 trial with 182 participants studied the effect of multiple doses of molnupiravir on people who developed Covid-19 symptoms in the previous week, tested positive for the disease during the most recent four days and were not hospitalized.

The tests did not detect infectious virus in any of the study volunteers who took molnupiravir twice a day after five days of treatment, while 24% of the subjects who received a placebo did so, Ridgeback reported at the virtual conference on retroviruses and opportunistic infections.

Individuals who took higher doses of the drug also had lower levels of infectious virus than the placebo group after three days.

Ridgeback Biotherapeutics co-founder Wayne Holman said the results indicate that the drug prevents the new coronavirus from replicating in the body and offers the first evidence that an oral antiviral drug can be effective against the virus.

The findings also suggest, but do not prove, that the drug can reduce disease, said Holman, who is also chief executive of Ridgeback Capital, an investment firm. Ridgeback Biotherapeutics has an approved treatment for Ebola.

Merck said it may have provisional results by the end of this month from two end-stage tests that explore whether molnupiravir helps prevent hospitalizations and deaths from Covid-19.