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Learning about a COVID-19 treatment for children at risk of severe disease

A PHASE 2/3, INTERVENTIONAL SAFETY, PHARMACOKINETICS, AND EFFICACY, OPEN-LABEL, MULTI-CENTER, SINGLE-ARM STUDY TO INVESTIGATE ORALLY ADMINISTERED PF-07321332 (NIRMATRELVIR)/RITONAVIR IN NONHOSPITALIZED SYMPTOMATIC PEDIATRIC PARTICIPANTS WITH COVID-19 WHO ARE AT RISK OF PROGRESSION TO SEVERE DISEASE

Phase 3 Interventional Pfizer · NCT05261139

This study is testing a COVID-19 medication to see if it helps children under 18 who are at risk for severe illness feel better and avoid serious complications.

Quick facts

PhasePhase 3
Study typeInterventional
Enrollment160 (estimated)
Ages0 Years to 17 Years
SexAll
SponsorPfizer Industry-sponsored
Locations73 sites (Phoenix, Arizona and 72 other locations)
Trial IDNCT05261139 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to evaluate the safety and effectiveness of the medication nirmatrelvir/ritonavir in treating COVID-19 in pediatric patients under 18 years of age who are not hospitalized but are at risk for severe disease. Participants will receive the study medication within 72 hours of confirmed SARS-CoV-2 infection and must exhibit COVID-19 symptoms. The study will assess how the drug is processed in the body and its efficacy in alleviating symptoms and preventing severe illness.

Who should consider this trial

Good fit: Ideal candidates are children aged 0 to under 18 years with confirmed COVID-19 and at least one risk factor for severe illness.

Not a fit: Patients who have been hospitalized for COVID-19 or have severe renal impairment may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a new treatment option for children at risk of severe COVID-19.

How similar studies have performed: Other studies have shown promise in treating COVID-19 with antiviral medications, making this approach potentially beneficial.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion criteria:

* Male and female, age 0 to \< 18 years, able to swallow for some participants
* Confirmed SARS-CoV-2 infection within 72 hours prior to enrollment
* Initial onset of COVID-19 signs/symptoms within 5 days prior to the day of enrollment and at least 1 of the specified COVID-19 signs/symptoms present at enrollment
* Has at least 1 characteristic or underlying medical condition associated with an increased risk of developing severe illness from COVID-19

Exclusion Criteria:

* History of or need for hospitalization for the medical treatment of COVID-19
* Total bilirubin \>=2X upper limit of normal (ULN) (except for Gilbert's syndrome)
* Receiving dialysis or have known moderate to severe renal impairment
* Suspected or confirmed concurrent active systemic infection other than COVID-19
* History of hypersensitivity or other contraindication to any of the components of the study intervention
* Current or expected use of any medications or substances that are highly dependent on CYP3A4 for clearance or strong inducers of cytochrome P450 (CYP)3A4
* Has received or is expected to receive antibody treatment, antiviral treatment or convalescent COVID-19 plasma
* Participating in another interventional clinical study with an investigational compound or device, including those for COVID-19 through the study follow up
* Females who are pregnant or breastfeeding

Where this trial is running

Phoenix, Arizona and 72 other locations

+23 more sites — see ClinicalTrials.gov for the full list.

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
View on ClinicalTrials.gov → Find more trials like this →
Conditions COVID-19Severe acute respiratory syndrome coronavirus 2Pediatrics
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.