Enrolment is halted in Pfizer's Paxlovid trial with standard-risk population

Pfizer stops clinical trial as Paxlovid fails to prove efficacy in patients with low risk of severe disease.



Pfizer’s COVID-19 vaccine, Paxlovid has proven to be effective in patients that are at high risk of severe disease however the vaccine may not be as effective in less vulnerable patients. On Tuesday, the pharmaceutical giant announced that they plan to halt enrolment for their EPIC-SR trial as a study revealed that the vaccine was not effective in reducing symptoms in standard-risk patients. The clinical trial data showed a 51% relative risk reduction in standard-risk groups. The EPIC-SR trial was evaluating Paxlovid in standard-risk patients, these include vaccinated adults with at least one risk factor for progressing to severe disease as well as unvaccinated adults without additional risk. New data will be included in Pfizer’s upcoming application to the United States (U.S.) Food and Drug Administration for use in high-risk groups.


Earlier this month a study in Israel revealed that the vaccine reduces COVID-19 hospitalisations and death rates in unvaccinated and vaccinated patients over the age of 65 years, however the treatment did not prevent severe illness in younger adults. According to the Assistant Secretary for Preparedness and Response under the U.S. Department of Health and Human Services, over 1.2 million courses of Paxlovid have been administered in the U.S. Pfizer noted that they “will continue to evaluate treatment in populations with high unmet need.” In April the pharmaceutical company stated that their oral antiviral wasn’t effective in preventing COVID-19 infections in people exposed to the virus through household contact. Pfizer has reconfirmed its projection that Paxlovid will reach $22 billion sales globally this year.