Pfizer's Inc experimental oral drug that would be the first specifically designed to stop the novel coronavirus could be available by the end of this year.
The antiviral pill prevents the virus from spreading inside the body by blocking an enzyme that coronavirus needs to copy itself. The treatment belongs to a class of drugs known as protease inhibitors.
Known as PF-07321332, the medication would be prescribed to patients at the first sign of infection with COVID-19.
According to The Telegraph, the ongoing trial is split into three phases, running for a total of 145 days, meaning it is set to conclude in mid-July.
The first phase is concluding in May and, if larger trials go well, the drug could be distributed to hospitals and doctors' offices by autumn 2021.
Developing drugs for respiratory diseases is tough, partly because doses have to be high enough for the medicine to reach deep into the lungs yet not so high that they're toxic.
Research on Covid treatments was also throttled because the U.S. government initially gave priority to vaccines.
It wasn't until the end of April 2020 that the first COVID-19 treatment showed benefit in a big government-sponsored study.
That drug - remdesivir, sold as Veklury by Gilead Sciences Inc - remains the only one approved for COVID-19 in the U.S., though some others are authorized for emergency use (a form of tentative approval with a lower bar for safety and efficacy).
According to clinicaltrials.gov, the Covid pill trial is being run at two Pfizer locations, one in New Haven, Connecticut, and the other in Brussels, Belgium.
A total of 60 participants are enrolled between the ages of 18 and 60 with some participants will be given one of four doses of the drug and others the placebo, but even researchers won't know what pill the volunteers.
The website, run by the U.S. National Library of Medicine, states that study is estimated to be completed by May 25.
If results show the medication is safe and effective, the company will move on to Phase II and recruit a larger group of participants, and even be available later this year.
'If they have moved to this stage, they will be quietly optimistic,' Dr Penny Ward, a visiting professor in pharmaceutical medicine at King's College London, told The Telegraph.
'The question will be about how the drug is tolerated...They will be going like the clappers.'
In the U.S., the National Institutes of Health (NIH) launched the Accelerating COVID-19 Therapeutic Interventions and Vaccines (ACTIV) on April 17.
The program is focused on developing therapeutics against the coronavirus, its variants and other viruses with the potential to cause pandemics.
Although Pfizer is listed as one of the member companies of ACTIV, it is unclear if PF-07321332 is one of the drugs being studied or if the NIH is helping to fund the trial.
Neither the NIH nor the U.S. Department of Health and Human Services immediately returneduest for comment in time for publication.
A spokeswoman for Pfizer refused to answer questions about whether any government agencies are funding clinical trials and if the U.S. has placed any orders for the drug.
© Associated Newspapers Ltd.