The Kellys have a role in developing what could be the world’s next chance to thwart covid: a short-term regimen of daily pills that can fight the virus early after diagnosis and conceivably prevent symptoms from developing after exposure, says an article published in CNN.
A clinical trial
Within a day of testing positive for covid-19 in June, Miranda Kelly was sick enough to be scared. “But the Kellys, who live in Seattle, had agreed just after their diagnoses to join a clinical trial at the nearby Fred Hutch cancer research center that’s part of an international effort to test an antiviral treatment that could halt covid early in its course.” By the next day, the couple was taking four pills, twice a day. Antivirals are already essential treatments for other viral infections, including hepatitis C and HIV.
Three promising antivirals
At least three promising antivirals for covid are being tested in clinical trials, with results expected as soon as late fall or winter, said Carl Dieffenbach, director of the Division of AIDS at the National Institute of Allergy and Infectious Diseases, who is overseeing antiviral development.
“I think that we will have answers as to what these pills are capable of within the next several months”, Dieffenbach said. The top contender is a medication from Merck & Co. and Ridgeback Biotherapeutics called Molnupiravir, Dieffenbach said.
Products being tested
This is the product being tested in the Kellys’ Seattle trial. Two others include a candidate from Pfizer, known as PF-07321332, and AT-527, an antiviral produced by Roche and Atea Pharmaceuticals.
They work by interfering with the virus’s ability to replicate in human cells. In the case of Molnupiravir, the enzyme that copies the viral genetic material is forced to make so many mistakes that the virus can’t reproduce.
Approved antiviral drugs
That, in turn, reduces the patient’s viral load, shortening infection time and preventing the kind of dangerous immune response that can cause serious illness or death.
So far, only one antiviral drug, Remdesivir, has been approved to treat covid. By contrast, the top contenders’ understudy can be packaged as pills. Sheahan, who also performed preclinical work on Remdesivir, led an early study in mice that showed that Molnupiravir could prevent early disease caused by SARS-CoV-2, the virus that causes covid.
The formula was discovered at Emory University and later acquired by Ridgeback and Merck. Clinical trials have followed, including an early trial of 202 participants last spring that showed that Molnupiravir rapidly reduced the levels of infectious virus.
Merck chief executive Robert Davis said this month that the company expects data from its larger phase 3 trials in the coming weeks, with the potential to seek emergency use authorization from the Food and Drug Administration “before year-end”.
Pfizer’s product trial
Pfizer launched a combined phase 2 and 3 trial of its product on Sept.1 and Atea officials said they expect results from phase 2 and phase 3 trials later this year.
If the results are positive and emergency use is granted for any product, Dieffenbach said, “distribution could begin quickly”. That would mean millions of Americans soon could have access to a daily orally administered medication, ideally a single pill, that could be taken for five to 10 days at the first confirmation of covid infection.
In June, the Biden administration announced it had agreed to obtain about 1.7 million treatment courses of Merck’s Molnupiravir, at a cost of $1.2 billion, if the product receives emergency authorization or full approval.
Potent antiviral treatments
The same month, the administration said it would invest $3.2 billion in the Antiviral Program for Pandemics, which aims to develop antivirals for the covid crisis and beyond, Dieffenbach said.
The pandemic kick-started a long-neglected effort to develop potent antiviral treatments for coronaviruses said, Sheahan. Widely available antiviral drugs would join the monoclonal antibody therapies already used to treat and prevent serious illness and hospitalizations caused by covid.
The lab-produced monoclonal antibodies, which mimic the body’s natural response to infection, were easier to develop but must be given primarily through intravenous infusions.
Pills prove effective
They would be another tool to fight covid. One challenge in developing antiviral drugs quickly has been recruiting enough participants for the clinical trials, each of which needs to enroll many hundreds of people, said Dr. Elizabeth Duke, a Fred Hutch research associate overseeing its Molnupiravir trial. Participants must be unvaccinated and enrolled in the trial within five days of a positive covid test.
If the antiviral pills prove effective, the next challenge will be ramping up a distribution system that can rush them to people as soon as they test positive. Merck officials predicted the company could produce more than 10 million courses of therapy by the end of the year. Atea and Pfizer have not released similar estimates. Studies evaluating whether antivirals can prevent infection after exposure.
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Source: https://edition.cnn.com/2021/09/27/health/covid-treatment-pill-khn-partner/index.html
