(Ritonavir + PF-07321332) Oral Antiviral Cuts COVID-19 Hospitalization by 89%

[Jim Allen]

Positive results. Still pending peer review.

POZ.com writeup:
https://www.poz.com/article/oral-antiviral-cuts-covid19-hospitalization-nearly-90

In Short:

The Phase II/III EPIC-HR trial enrolled non-hospitalized adults with COVID-19 in North and South America, Europe, Africa and Asia who were at high risk of progressing to severe illness. They had mild to moderate symptoms starting no more than five days prior to enrollment, a positive SARS-CoV-2 test and at least one underlying condition associated with severe illness. They were randomly assigned to receive Paxlovid or a placebo twice daily for five days.

On November 5, Pfizer announced that a planned interim analysis of 1,219 participants showed an 89% reduction in the risk of COVID-19-related hospitalization or death from any cause in people who started treatment within three days of symptom onset. Three of the 389 patients treated with Paxlovid (0.8%) were hospitalized over 28 days, compared with 27 of the 385 (7.0%) people who received the placebo. No Paxlovid recipients and seven placebo recipients died.

Among those who started treatment within five days of symptom onset, six out of 607 Paxlovid recipients (1.0%) were hospitalized, and there were no deaths. In the placebo arm, 41 out of 612 patients (6.7%) were hospitalized, and there were 10 deaths. (This larger analysis included the participants treated within three days.)

Based on these findings, which have not yet been peer-reviewed or published, an independent data and safety monitoring board, in consultation with the FDA, recommended that the trial be stopped ahead of schedule. This typically happens when early results show that a therapy is either ineffective or so effective that it would be unethical to continue giving some participants a placebo.

Treatment was generally safe and well tolerated, according to Pfizer’s press release. Rates of treatment-emergent adverse events—mostly mild—were comparable in the Paxlovid and placebo arms (19% and 21%, respectively). Side effects and drug resistance are less likely to be a concern for a medication taken for only five days, unlike drugs used for lifelong HIV treatment. In preclinical studies, it did not show evidence of mutagenesis.