Paxlovid not effective for post-exposure prophylactic use in clinical trial

Pfizer has announced results of the EPIC-PEP (Evaluation of Protease Inhibition for COVID-19 in Post-Exposure Prophylaxis) study, which evaluated Paxlovid (nirmatrelvir tablets and ritonavir tablets) for COVID-19 post-exposure prophylactic use.1,2 The study included 2,957 adults with a negative SARS-CoV-2 rapid antigen test result. All participants were asymptomatic household contacts with exposure (within the previous 96 hours) to an individual who was symptomatic and recently tested positive for SARS-CoV-2. Patients were randomized to receive Paxlovid twice daily for five days followed by placebo for five days, Paxlovid twice daily for 10 days, or placebo twice daily for 10 days.1 Results showed risk reductions of 32% and 37% in adults who received Paxlovid for five and 10 days, respectively, compared to placebo. However, these results were not statistically significant and the primary endpoint of reducing the risk of confirmed and symptomatic COVID-19 infection in adults who had been exposed to the virus through a household contact was not met.1 Full study data, which will include analyses of secondary endpoints and subgroups, are expected to be released in the coming months and submitted to a peer-reviewed publication.1 In commenting on the study results, Pfizer’s chairman and chief executive officer, Albert Bourla, stated that, “While we are disappointed in the outcome of this particular study, these results do not impact the strong efficacy and safety data we’ve observed in our earlier trial for the treatment of COVID-19 patients at high risk of developing severe illness.”1 In Canada, Paxlovid is approved for the treatment of mild-to-moderate COVID-19 in adults with positive results of direct SARS-CoV-2 viral testing, and who are at high risk for progression to severe COVID-19, including hospitalization or death. Paxlovid is not authorized for pre-exposure or post-exposure prophylaxis for prevention of COVID-19 or for use for longer than five consecutive days.3 References 1. Pfizer, Inc. Pfizer shares top-line results from phase 2/3 EPIC-PEP study of Paxlovid for post-exposure prophylactic use. April 29, 2022.(accessed May 5, 2022). 2. US Food & Drug Administration. Pfizer’s COVID-19 drug Paxlovid fails in postexposure clinical trial. FDA News May 3, 2022. (accessed May 5, 2022). 3. Pfizer Canada ULC. Paxlovid (nirmatrelvir tablets and ritonavir tablets) product monograph. Kirkland, QC; January 17, 2022. (accessed May 5, 2022).

Paxlovid not effective for post-exposure prophylactic use in clinical trial

Register for free access or login.

Related Topics