# A Study to Learn About the Study Medicines (Nirmatrelvir Plus Ritonavir) in People Aged 12 Years or Older With COVID-19 and a Compromised Immune System

> **NCT05438602** · PHASE2 · COMPLETED · sponsor: **Pfizer** · enrollment: 158 (actual)

## Conditions studied

- COVID-19

## Interventions

- **DRUG:** Nirmatrelvir
- **DRUG:** Ritonavir
- **DRUG:** Placebo for nirmatrelvir
- **DRUG:** Placebo for ritonavir

## Key facts

- **NCT ID:** NCT05438602
- **Lead sponsor:** Pfizer
- **Sponsor class:** INDUSTRY
- **Phase:** PHASE2
- **Study type:** INTERVENTIONAL
- **Status:** COMPLETED
- **Start date:** 2022-08-03
- **Primary completion:** 2023-07-17
- **Final completion:** 2023-11-13
- **Target enrollment:** 158 (ACTUAL)
- **Last updated:** 2024-09-23


## Primary source

ClinicalTrials.gov registry: https://clinicaltrials.gov/study/NCT05438602

## Citation

> US National Library of Medicine, ClinicalTrials.gov registration NCT05438602, "A Study to Learn About the Study Medicines (Nirmatrelvir Plus Ritonavir) in People Aged 12 Years or Older With COVID-19 and a Compromised Immune System". Retrieved via AI Analytics 2026-06-09 from https://api.ai-analytics.org/clinical/NCT05438602. Licensed CC0.

---

*[Clinical trials dataset](/datasets/clinical-trials) · CC0 1.0*