Thread by @bansisharma

1. Pfizer's Paxlovid Pill Can Be A Game-Changer, Making Covid Vaccinations Moot

Pfizer said its Covid-19 pill reduced hospitalizations and deaths in high-risk patients by 89%, a result that has the potential to upend how Covid-19 is treated and alter the course of the pandemic.

https://twitter.com/bansisharma/status/1456588327164039170

2. Pfizer said in a statement on Friday that it was no longer taking new patients in a clinical trial of the treatment “due to the overwhelming efficacy” and planned to submit the findings to U.S. regulatory authorities for emergency authorization as soon as possible.

3. A pill that could be taken at home at the first sign of symptoms is a crucial tool for taming the Covid-19 crisis globally, so long as it’s widely available.

4. In Pfizer’s trial of 1,219 unvaccinated adults, five days of treatment with its drug dramatically reduced the rate of hospitalization when it was started within either three days or five days of symptom onset.

5. The drug, Paxlovid, binds to an enzyme called a protease to stop the virus from replicating itself. Some drugs for HIV work in a similar way.

6. Current treatment options for Covid aren’t ideal. Monoclonal antibodies from companies like Regeneron and Eli Lilly reduce hospitalizations, but the infusions are hard to manufacture and must be given in a medical office, adding to the strain on health systems.

7. Other medications like Gilead Sciences Inc.’s remdesivir are used to treat much sicker people who are already in the hospital. Low-cost steroid dexamethasone, while very effective, is usually only given to gravely ill patients.

8. The need for a pill is so acute that Merck has already agreed to allow generic drugmakers to apply for licenses to make its treatment for more than 100 low- and middle-income nations, before it has even been cleared in the U.S.

9. The U.K.’s drug regulators became the first in the world to greenlight Merck’s drug Thursday after a swift review. Now Pfizer’s pill, which works by a different mechanism, appears to have produced even better results in high-risk patients.

10. In addition to the current trial in high-risk patients, Pfizer is also testing the drug in standard-risk patients, a study that included some vaccinated people who had breakthrough infections.

11. In a third large trial, Pfizer is exploring if the drug could be used as a prophylactic medicine for people who live with someone who has come down with Covid-19, meaning a person would take the drug to avoid contracting the virus.

12. An old molecule. The pill was internally developed by Pfizer researchers in the U.S. and U.K. During the early pandemic shutdowns, the scientists agreed to come back to their labs in an urgent effort to develop anti-Covid pills.

13. They dusted off an old experimental antiviral drug that Pfizer had developed after the original SARS epidemic, a coronavirus cousin to Covid-19 that killed about 800 people starting in late 2002. The old drug needed to be administered intravenously.

14. But by July of last year, the Pfizer researchers tweaked the original molecule and came up with a new compound that turned out to be highly potent against Covid-19 and other coronaviruses in the test tube -- and could be used as a pill.

15. The Pfizer drug works to block a crucial enzyme that the Covid-19 virus needs to replicate. It is taken twice a day for five days and used in combination with a second medicine called ritonavir that helps the Pfizer compound stay in the bloodstream longer.

16. We will have to wait and see how this develops, but ultimately a pill that can be used to treat Covid-19 when someone falls sick, rather than requiring billions of healthy people to be vaccinated, is just what is needed to deal with the scourge of Covid-19 globally.

The End