By Clara-Laeila Laudette
(Reuters) - Britain expects to have antiviral COVID-19 pills produced by Merck & Co Inc and Pfizer available over the winter, its Antiviral Taskforce Chair said on Thursday, as Omicron continues its lightning advance through the country.
Eddie Gray told reporters he expected both Merck's molnupiravir and Pfizer's paxlovid treatments to be available throughout the winter period, which he defined as between now and the end of March. Britain has yet to approve paxlovid.
"If there's a successful approval of paxlovid we'll want to fold that into the PANORAMIC process," Gray said, referring to a U.K. clinical trial examining the real-world efficacy of antiviral treatments against Omicron within a highly-vaccinated population.
Britain last month became the first country to approve monulpiravir, jointly developed with Ridgeback Biotherapeutics and for which Merck says it has signed deals totalling more than 7 million courses.
PANORAMIC is currently underway, trialling Merck's pill in COVID-19 patients at risk of serious illness in a bid to avoid hospitals overloading. It has enlisted more than 250 people out of a target of 10,000 subjects, Gray said.
"Early treatment in the community could have the furthest reach and impact here," chief investigator Professor Chris Butler told reporters. "Diminishing the burden on hospitals and getting people recovering quicker is the next phase in this area of research."
Recent data from separate trials, however, showed the drug only reduced hospitalisations and deaths among high-risk patients by around 30% - compared with 89% for rival Pfizer's paxlovid. Britain has purchased 500,000 monulpiravir doses.
Asked why PANORAMIC did not simply pivot to testing paxlovid's efficacy, professor Butler told reporters: "It's not yet approved and not yet available - evidence emerging for paxlovid has been subsequent to monulpiravir, hence the lag between the two."
"It's a question of getting on with what's available."
The hope is that PANORAMIC will shed light on which COVID-19 palliatives reduce hospitalisation rates, prevent severe cases, sidestep immune resistance, and prove cost-effective.
Whether such drugs could be used to protect people from becoming ill after being exposed to a positive case - known as post-exposure prophylaxis - is another possibility scientists and regulators are keen to explore.
"Antivirals will be a way of dealing with COVID-19 over the winter and in the long run, as well as answering questions like efficacy as a post-exposure prophylaxis," said Professor Phil Evans of the National Institute of Health Research.
The monulpiravir treatment is still under review by the European Medicines Agency, but the EU drug regulator issued advice in November on using it for older adults ahead of providing any wider recommendation.
The EMA said on Thursday European Union countries can use paxlovid early after diagnosis of an infection even though its full review for regulatory approval has not been completed.
Both paxlovid and monulpiravir work by impairing the coronavirus's replication, sparking hope that such a mechanism could prove effective against other mRNA viruses like SARS and MERS according to NHSE (National Health Service England) Dr David Lowe.
(Reporting by Clara-Laeila Laudette; Editing by Alison Williams and Philippa Fletcher)