INTERNATIONAL: Pfizer has announced on Tuesday the final analysis of its antiviral COVID-19 pills showing near 90% efficacy in preventing hospitalizations and deaths in high-risk patients. Recent lab data suggests the drug retains its effectiveness against the fast-spreading Omicron variant of the coronavirus. Pfizer announces additional phase 2/3 study results confirming robust efficacy of Novel COVID-19 Oral Antiviral Treatment Candidate in Reducing Risk of Hospitalization or Death, the successful trial of its novel COVID-19 oral antiviral candidate Paxlovid tablets and Ritonavir tablets.

The U.S. drugmaker Pfizer last month has said the oral medicine was around 89% effective in preventing hospitalizations or deaths when compared to placebo, based on interim results in around 1,200 people. The data disclosed on Tuesday includes an additional 1,000 people. The Pfizer pills are taken with the older antiviral ritonavir every 12 hours for five days beginning shortly after onset of symptoms. If authorized, the treatment will be sold as Paxlovid.

Pfizer has also released early data from a second clinical trial suggesting that the treatment reduced hospitalizations by around 70% in a smaller trial of standard-risk adults, including some higher-risk vaccinated people. The results were not acknowledged as statistically significant, but Pfizer has claimed they showed a "positive data trend for reduction in risk."

Pfizer Chief Scientific Officer Mikael Dolsten has said he expects authorization for use in high-risk individuals from the U.S. Food and Drug Administration and other regulatory agencies soon. There are currently no oral antiviral treatments for COVID-9 authorized in the United States.

Rival Merck has asked for emergency use authorization of its antiviral pill Molnupiravir.

But that drug only reduced hospitalizations and deaths in its clinical trial of high-risk patients by around 30%. Some scientists have also raised safety concerns about the potential for birth defects from the Merck drug, as well as worries that it could cause the virus to mutate.

Accordingly, Pfizer's drug works differently. It is part of a class of drugs called protease inhibitors currently used to treat HIV, hepatitis C and other viruses. A recent laboratory testing shows that activity against the protease of the Omicron variant is as "good as basically any SARS-COV-2 variant of concern."

The company has said it can have 180,000 treatment courses ready to ship this year and plans to produce at least 80 million more in 2022. Pfizer, which makes one of the leading COVID-19 vaccines with German partner BioNTech, has agreed to allow generic manufacturers to supply versions of the drug to 95 low- and middle-income countries through a licensing agreement with international public health group Medicines Patent Pool.