Pfizer: Pfizer Initiates Phase 2/3 Study of Novel COVID-19 Oral Treatment in Pediatric Participants

Pfizer Inc. (NYSE: PFE) announced today that it has 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 a confirmed diagnosis of COVID-19 who are at risk of progression to severe disease.

“Since the beginning of the pandemic, more than 11 million children under the age of 18 in the United States alone have tested positive for COVID-19, representing nearly 18% of reported cases and leading to more than 100,000 hospital admissions. There is a significant unmet need for outpatient treatments that can be taken by children and adolescents to help prevent progression to severe illness, including hospitalization or death,” said Mikael Dolsten, Chief Scientific Officer and President, Worldwide Research, Development and Medical, Pfizer. “PAXLOVID is already authorized or approved in many countries around the world, with more than 1.5 million treatment courses delivered thus far and 30 million expected by July to help combat this devastating disease. We are proud to expand studies of our novel COVID-19 treatment to include pediatric participants to further evaluate the safety and efficacy of this treatment in this important population.”

The Phase 2/3 trial is 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 includes participants aged 6 to 17 weighing at least 40 kg [88 lbs], and Cohort 2 includes those aged 6 to 17 weighing more than 20 kg [44 lbs] and less than 40 kg [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 40 kg [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 and the adults with similar body weight who were included in the EPIC-HR trial. Data from the EPIC-PEDS study will provide further support for the dose recommendations in this population, as well as potentially expand the indication to younger age groups and lower weights.

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