The first pill to treat coronavirus could be available within months after it was found to cut hospitalisations and deaths by half.
If approved, the antiviral drug would be the first simple pill shown to be effective against Covid-19 and would mark a major advance in the fight against the pandemic. Other drugs such as dexamethasone are already saving the lives of the sickest patients in hospital but need to be given as injections or IV infusions.
The latest drug, made by Merck, known as MSD outside the US, and Ridgeback Biotherapeutics, would be the first that could be taken by at-risk patients at home. Merck said it would apply for emergency use authorisation for the drug in the US within the next two weeks and seek the green light for use in several other countries.
Experts anticipate that if further data supports the initial clinical trial results, the pills could be approved for treating high-risk patients within weeks of an application being made.
“It exceeded what I thought the drug might be able to do in this clinical trial,” said Dean Li, the vice-president of Merck research. “When you see a 50% reduction in hospitalisation or death, that’s a substantial clinical impact.”
The trial tracked 775 adults with mild to moderate Covid, who were considered higher risk for severe disease owing to health problems such as obesity, diabetes or heart disease. Half were given a five-day course of the pill, called molnupiravir, which comes in the form of small brown capsules taken twice a day.
Fifty-three patients (14%) in the placebo group were hospitalised, compared with only 28 (7%) of those who received the drug. There were no deaths in the drug group after that time period, compared with eight deaths in the placebo group, according to Merck.
The data from the study was made public in a press release on Friday and has not yet been peer-reviewed. However, an independent group of medical experts monitoring the trial recommended stopping it early because the interim results were so encouraging.
Prof Peter Openshaw, of Imperial College London, described the result as “remarkable if confirmed”, adding that disappointing trials of other antiviral drugs such as remdesivir had lowered expectations of a breakthrough. “We don’t really expect to see such impressive data from an antiviral,” he said.
Prof Peter Horby of the University of Oxford, said: “It’s really encouraging to see some positive clinical data in a trial. If the results hold out this would be a very positive result.”
Horby said caution was needed, however, as with relatively small numbers involved the efficacy figure can wobble up and down based on the outcomes of just a handful of patients.
Only limited information on side-effects was made public in the press release, but the company said rates were similar between the placebo group and the treated group.
Finding a convenient pill that patients can take at home is a widely held ambition. A stated goal of the UK government’s antivirals taskforce when it was launched in April was to find two such drugs with a view to deploying them over the winter.
Eddie Gray, the chair of the taskforce, described the results as “exciting” but would not confirm if the UK has preordered doses of the drug or how an emergency approval process for the drug would be handled in the UK.
The US government made an advance purchase of 1.7m doses of the drug at a cost of $1.2bn, and the company said on Friday it would use a “tiered pricing approach” to reflect countries’ ability to pay for the drug.
Janet Scott, of the University of Glasgow, who is leading the trial of another antiviral drug, described the results as “very exciting”. She said: “Ideally in the future we would hope for a well-tolerated drug that people can buy over the counter and take at the first suspicion of infection, before they even have the test result back, so we can target Covid-19 early.”
Covid infection rates are still mixed across the UK, according to the latest data from the Office for National Statistics. An estimated one in 85 people, or 658,800, will have tested positive in England in the week ending 25 September, up from one in 90 or 620,100 the week before. Infection rates are up marginally in Wales too, from one in 60 to one in 55, but down slightly in Northern Ireland and Scotland, where rates are one in 65 and one in 55 respectively.
Infections are rising steeply among children at secondary school, according to the ONS, where 4.6% will have tested positive in the week surveyed, up from 2.7% two weeks earlier. While cases overall are falling in London and the north-east of England, they are rising in the north-west, Yorkshire and the Humber, the east Midlands and the south-west.