FDA Approves Pfizer’s Paxlovid for Treatment of COVID-19 in Adults

The FDA has approved the Pfizer’s nirmatrelvir tablets and ritonavir tablets, co-packaged as Paxlovid, for the treatment of mild-to-moderate COVID-19 in adults who are at high risk for disease progression to severe COVID-19, including hospital or death.

This marks the fourth drug, and first oral antiviral pill, approved by the FDA to treat adults with COVID-19.

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“While the pandemic has been challenging for all of us, we have made great progress mitigating the impact of COVID-19 on our lives,” Patrizia Cavazzoni, MD, director for the Center for Drug Evaluation and Research at the FDA, said in a press release. “Today’s approval demonstrates that [nirmatrelvir and ritonavir tablets have] met the agency’s rigorous standards for safety and effectiveness, and that it remains an important treatment option for people at high risk for progression to severe COVID-19, including those with prior immunity. The FDA remains committed to working with sponsors to facilitate the development of new prevention and treatment options for COVID-19.”

Nirmatrelvir and ritonavir tablets were manufactured and packaged under Emergency Use Authorization. It will continue to be distributed by the US Department of Health and Human Services to increase access for adults as well as treatment of eligible children aged 12 to 18 years old who are not covered by the full approval.

It is currently not approved or authorized for the use as a pre-exposure or post-exposure prophylaxis for prevention of a COVID-19 infection.

The efficacy of nirmatrelvir and ritonavir tablets was supported by the final results of the EPIC-HR trial (NCT04960202), a randomized, double-blind, placebo-controlled trial. The study was designed to determine the impact of nirmatrelvir and ritonavir tablets for the treatment of non-hospitalized symptomatic adults with a laboratory confirmed diagnosis of COVID-19.

Individuals included in the study were aged 18 years and older with a prespecified risk factor for severe disease or were 60 years and older regardless of chronical medical conditions.

All individuals included had not received a COVID-19 vaccine nor had they been previously infected with COVID-19. The analysis included 977 individuals who received nirmatrelvir and ritonavir tablets and 989 individuals who received the placebo.

Investigators found that nirmatrelvir and ritonavir tablets reduced the proportion of patients with COVID-19-related hospitalizations or death from any cause through 28 days of follow up at 86% compared to the placebo among those who were treated within 5 days of symptom onset and those who did not received a COVID-19 therapeutic monoclonal antibody treatment.

It was reported that approximately 0.9% of individuals receiving nirmatrelvir and ritonavir tablets were hospitalized due to COVID-19 or died from any cause within the 28 days of follow up compared to 6.5% who had the placebo.

The benefits of nirmatrelvir and ritonavir tablets was also observed in individuals who had prior immunity to the virus that caused COVOD-19. In the EPIC-HR study, individuals who were antibody positive at the enrollment of the trial and were treated with the drug had a decreased risk of COVID-19-related hospitalization or death from any cause at 0.2% at the 28 day follow up compared to 1.7% of those treated with the placebo.

The FDA also added that based on data currently available, there has been no association between nirmatrelvir and ritonavir tablets and COVID-19 rebound.

Reference

FDA approves first oral antiviral for treatment of COVID-19 in adults. News release. US Food and Drug Administration. May 25, 2023. Accessed May 25, 2023. https://www.fda.gov/news-events/press-announcements/fda-approves-first-oral-antiviral-treatment-covid-19-adults?utm_medium=email&utm_source=govdelivery