On Mar. 9, 2022, Pfizer announced that it had initiated a Phase 2/3 study, EPIC-PEDS (Evaluation of ProteaseInhibition forCOVID-19 in Pediatric Patients), to evaluate the safety, pharmacokinetics, and efficacy of Pfizerﾒs PAXLOVIDﾙ (nirmatrelvir [PF-07321332] tablets and ritonavir tablets) in non-hospitalized, symptomatic, pediatric participants with a confirmed diagnosis of COVID-19 who are at risk of progression to severe disease.

The Phase 2/3 trial was an open-label, multi-center, single-arm study in approximately 140 pediatric participants under 18 years of age. Initial enrollment features two cohorts; Cohort 1 included participants aged 6 to 17 weighing at least 40 kg [88 lbs], and Cohort 2 included those aged 6 to 17 weighing more than 20 kg [44 lbs] and less than 40 kg [88 lbs]. An independent Data Monitoring Committee (DMC) reviewed safety data of participants in each cohort.

Data from the Phase 2/3 study of non-hospitalized, high-risk adults with COVID-19 showed PAXLOVID reduced risk of hospitalization or death by 89% (within three days of symptom onset) and 88% (within five days of symptom onset) from any cause compared to placebo, with no deaths observed in the treatment group. Treatment-emergent adverse events were comparable between PAXLOVID (23%) and placebo (24%), most of which were mild in intensity.