EPIC-HR: Study of Oral PF-07321332/Ritonavir Compared With Placebo in Nonhospitalized High Risk Adults With COVID-19
Summary
The purpose of this study is to determine whether PF-07321332/ritonavir is safe and effective for the treatment of adults who are ill with COVID-19 and do not need to be in the hospital, but are at an increased risk of developing severe illness. Throughout the study period, provision will be made to allow study visits to be conducted at a participant's home or another non-clinic location if available. The total study duration is up to 24 weeks.
Timeline
- Start
- 2021-07-16
- Primary completion
- 2021-12-09
- Completion
- 2022-04-25
Outcome
Met primary endpoint
registry analysis (superiority test); PF-07321332 300 mg + Ritonavir 100 mg vs Placebo; p <0.0001; Percentage difference -6.137 (95% CI -8.208 to -4.066); Normal approximation NCT04960202 ↗
registry NUMBER PF-07321332 300 mg + Ritonavir 100 mg: 0.752 (0.313 to 1.796) Percentage of participants NUMBER Placebo: 6.888 (5.172 to 9.146) Percentage of participants NCT04960202 ↗
release “interim analysis of the Phase 2/3 EPIC-HR study, which demonstrated an 89% reduction in risk” pfizer.com ↗
release “In the final analysis of the primary endpoint from all patients enrolled in EPIC-HR, an 89% reduction in COVID-19-related hospitalization or death” pfizer.com ↗
release “EPIC-HR, an 89% reduction in COVID-19-related hospitalization or death from any cause compared to placebo” pfizer.com ↗
release “In the final analysis of the primary endpoint from all patients enrolled in EPIC-HR, an 89% reduction in COVID-19-related hospitalization” pfizer.com ↗
Publications
- Ansari W, Coetzer H, Gebo KA, Ren J, Scott A, Cappelleri JC, Cha-Silva AS, Leister-Tebbe H. Patient-Reported Outcomes of Nirmatrelvir Treatment for High-Risk, Nonhospitalized Adults With Symptomatic COVID-19. Open Forum Infect Dis. 2025 Aug 1;12(8):ofaf449. doi: 10.1093/ofid/ofaf449. eCollection 2025 Aug.
- Baniecki ML, Guan S, Rai DK, Yang Q, Lee JT, Hao L, Weinstein E, Hyde C, Cardin RD, Soares H, Hammond J. Integrated virologic analysis of resistance to nirmatrelvir/ritonavir in individuals across four phase 2/3 clinical studies for the treatment of COVID-19. EBioMedicine. 2025 Aug;118:105819. doi: 10.1016/j.ebiom.2025.105819. Epub 2025 Jun 30.
- Hammond J, Leister-Tebbe H, Gardner A, Abreu P, Bao W, Wisemandle W, Ansari W, Harrington MA, Simon-Campos A, Chew KW, Pypstra R, Rusnak JM. Alleviation of COVID-19 Symptoms and Reduction in Healthcare Utilization Among High-risk Patients Treated With Nirmatrelvir/Ritonavir (NMV/R): A Phase 3 Randomized Trial. Clin Infect Dis. 2025 Feb 24;80(2):323-330. doi: 10.1093/cid/ciae551.
- Hammond J, Leister-Tebbe H, Gardner A, Abreu P, Bao W, Wisemandle W, Baniecki M, Hendrick VM, Damle B, Simon-Campos A, Pypstra R, Rusnak JM; EPIC-HR Investigators. Oral Nirmatrelvir for High-Risk, Nonhospitalized Adults with Covid-19. N Engl J Med. 2022 Apr 14;386(15):1397-1408. doi: 10.1056/NEJMoa2118542. Epub 2022 Feb 16.
Drugs
| Evaluation | Drug | Modality | Dose | Route |
|---|---|---|---|---|
| Subject | Nirmatrelvir | Small molecule | 300 mg | Oral |
| Background | Ritonavir | Other / unclassified | 100 mg | Oral |