Pfizer says its COVID-19 treatment reduces the risk of hospitalization and death by 89%

Pharmaceutical company Pfizer announced an interim report of phase 2 and 3 clinical trials of the oral antiviral drug PAXLOVID, a treatment for COVID-19, and reported that it succeeded in reducing the risk of hospitalization or death due to COVID-19 by 89%. Pfizer plans to file an emergency use authorization application by submitting data to the FDA.

Paxrobead is an oral drug that combines PF-07321332, a protease inhibitor, and Ritonavir. Drink after being diagnosed with COVID-19 to reduce the aggravation rate. to reduce the risk of hospitalization and death. PF-07321332 was developed as a treatment for COVID-19 as of April 2021 and is a drug designed to block the activity of SARS-CoV-2-3CL protease, an enzyme required for COVID-19 self-replication. Combination of ritonavir works to slow the metabolism or breakdown of PF-07321332 and to maintain PF-07321332 activity in the body for a long time.

According to Pfizer, the Paxrovid trial was conducted in 1,219 patients. The 607 patients who received Paxrovide within 5 days of the onset of COVID-19 had 6 hospitalizations and 0 deaths, whereas the placebo-treated control group had 41 hospitalizations and 10 deaths. The hospitalization and mortality rate of patients in the control group was 6.7%, but it is reported that the risk decreased by 85% to 1% in the paxrovid-treated group.

In addition, the hospitalization and mortality rate of patients who received treatment within 3 days of symptom onset was 7% in the control group, but 0.8% in the group administered with Paxrovid, an 89% reduction in risk.

An oral antiviral drug for COVID-19 is molnupiravir announced by Merck. Molnupiravir is similar to paxrobead in that it inhibits RNA synthesis, but the mechanism of action is slightly different. Molnupiravir has been pointed out for its mutagenicity in human cells, and there are voices expressing concerns about its safety. Pfizer also reported that PF-07321332 did not show mutagenicity in preclinical studies.

Pfizer is appealing for the safety of Paxrovid by revealing that the discontinuation of the test due to serious side effects was almost equal to that of the control group, and most of them were light. Pfizer said it had safety data from 1,881 patients at the time of interim analysis and is preparing to submit this data to the FDA for an emergency use authorization application. In addition, Merck has already submitted data on molnupiravir to the FDA, and an FDA advisory committee meeting will be held on November 30, 2021.

According to the report, molnupiravir is more advantageous than paxrovid in terms of ease of use, and in fact, it has already been approved in the UK and is being reviewed in the US. Experts also predicted that global demand for oral treatment options is expected anyway, and Pfizer and Merck at least for the foreseeable future, as stockpiles are expected for both molnupiravir and paxrovid. Related information can be found here.