Pfizer initiated a Phase 2/3 study, EPIC-PEDS (Evaluation of Protease Inhibition for COVID-19 in Pediatric Patients), to evaluate the safety, pharmacokinetics, and efficacy of Pfizer’s PAXLOVID (nirmatrelvir [PF-07321332] tablets and ritonavir tablets) in non-hospitalized, symptomatic, pediatric participants with confirmed COVID-19 who are at risk of progression to severe disease.
 
The Phase 2/3 trial is an open-label, multi-center, single-arm study in approximately 140 pediatric participants under 18 years of age. Cohort 1 includes participants aged 6 to 17 weighing at least 88 lbs, and Cohort 2 includes those aged 6 to 17 weighing more than 44 lbs and less than 88 lbs.

Participants enrolled in Cohort 1 will receive PAXLOVID (nirmatrelvir/ritonavir 300 mg/100 mg) orally twice daily for five days (10 doses total), the current authorized dosing for pediatric patients 12 years of age and older weighing at least 40kg.
 
Participants enrolled in Cohort 2 will receive PAXLOVID (nirmatrelvir/ritonavir 150 mg/100 mg) orally twice daily for five days (10 doses total).
 
Pfizer is also working to develop an age-appropriate formulation for three additional planned cohorts of younger than 6 years old and will enroll the trial to include these younger age groups as data from Cohorts 1 and 2 and the new formulation are available.

An independent Data Monitoring Committee (DMC) will review 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.

The safety and effectiveness of PAXLOVID have not yet been directly established in pediatric patients. Although other PAXLOVID clinical trials did not include participants under the age of 18, the FDA authorized PAXLOVID for emergency use in pediatric patients 12 years of age and older weighing at least 88lbs as pharmacokinetic-pharmacodynamic (PK/PD) modeling determined that the authorized adult dosing regimen would result in comparable blood concentration levels of PAXLOVID in this population. 

PAXLOVID is currently authorized or approved in more than 50 countries across the globe.