Several firms developing anti-Covid pills; Pfizer starts large trial

As Merck & Co and Pfizer prepare to report clinical trial results for experimental Covid-19 antiviral pills, rivals are lining up with what they hope will prove to be more potent and convenient oral treatments of their own.

Enanta Pharmaceuticals, Pardes Biosciences, Japan's Shionogi & Co and Novartis AG said they have designed antivirals that specifically target the coronavirus while aiming to avoid potential shortcomings such as the need for multiple pills a day or known safety issues.

Infectious disease experts stressed that preventing Covid-19 through wide use of vaccines remains the best way to control the pandemic.

But they said the disease is here to stay and more convenient treatments are needed.

"We need to have oral alternatives for suppression of this virus. We have people who aren't vaccinated getting sick, people whose vaccine protection is waning, and people who can't get vaccinated," said Dr Robert Schooley, an infectious diseases professor at UC San Diego School of Medicine.

Pfizer and Merck, as well as partners Atea Pharmaceuticals and Roche AG have all said they could seek emergency approval for their Covid-19 pills this year.

Pfizer said on Monday it begun a middle-to-late stage trial involving 2,660 adults.

"We believe that tackling the virus will require effective treatments for people who contract, or have been exposed to, the virus, complementing the impact that vaccines have had," said Pfizer chief scientific officer Mikael Dolsten.

Pfizer started developing its drug, called PF-07321332, in March last year and is testing it in combination with ritonavir, a repurposed HIV medicine. If it works in real life, it will likely only be effective at the early stages of infection. - REUTERS, AFP