Pfizer-BioNTech will stop adding patients to its Paxlovid phase 2/3 trial after failing to prove the antiviral treatment reduced the relative risk of contracting COVID-19.
The drugmaker could not produce statistically significant data on whether the nation's most prescribed COVID-19 treatment was effective in reducing the risk of hospitalizations and deaths, according to a June 14 news release.
The results hit a snag in Paxlovid's already murky progress, which recently faced discrepancies over rebound symptoms. The CDC warned May 25 symptoms could reappear between two to eight days after testing negative, while the Mayo Clinic said June 14 that the risk is rare.
The company said in the release that it plans to continue testing Paxlovid's efficacy in high-risk populations.