NCT05386472

A Study to Learn About the Study Medicine (Nirmatrelvir Plus Ritonavir) in Pregnant Women With COVID-19

Terminated Phase 1 Last updated 29 July 2025

What this trial tests

Phase 1 trial testing nirmatrelvir in COVID-19 in 25 participants. Terminated before completion.

Timeline

22 June 2022

Primary endpoint
26 March 2025

12 May 2025

Quick facts

Lead sponsor	Pfizer
Phase	Phase 1
Status	Terminated
Study type	INTERVENTIONAL
Allocation	non randomized
Design	parallel
Masking	none
Primary purpose	treatment
Enrollment	25
Start date	22 June 2022
Primary completion	26 March 2025
Estimated completion	12 May 2025
Sites	13 locations across United States

Drugs / interventions tested

• nirmatrelvir (Nirmatrelvir) — full drug profile →
• ritonavir (ritonavir) — full drug profile →

Conditions studied

• COVID-19 — all drugs for COVID-19 →

Sponsor

Pfizer — full company profile →

Who can join

Adults 18 to 50, female only, with COVID-19. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

The purpose of this clinical trial is to learn about how study medicine (Paxlovid, which contains nirmatrelvir and ritonavir) is changed and eliminated from the body, as well as its safety, and the extent to which side effects can be tolerated for treatment of pregnant women with mild or moderate COVID-19 compared to non-pregnant women with mild or moderate COVID-19.

This study is seeking participants who:

* are expecting a healthy baby and are in their second or third trimester pregnancy and have mild or moderate COVID-19
* are not pregnant and have mild or moderate COVID-19.

All participants in this study will take Paxlovid by mouth every 12 hours for 5 days. We will study the experiences of people receiving the study medicine. This will help us decide if the study medicine is safe.

All participants will take part in this study for at least 34 days; pregnant participants will take part until their delivery, so that the study duration may be up to 6 months, depending on their delivery date.

During this time, participants will have 7to 8 visits and, if pregnant, a visit at delivery. Around 2 to 3 visits and the delivery visit will be done in person (at the clinic or at the participant's home). The other 5 visits may be done over the phone, unless in-person visit is necessary as decided by the doctor. Blood samples will be collected on the first 4 to 5 study visits (and at other study visits, if necessary).

Publications & conference data

5 peer-reviewed publications reference this trial (live from Europe PMC):

1. Oral antiviral treatments for COVID-19: opportunities and challenges.
   Rahmah L, Abarikwu SO, Arero AG, Essouma M, et al · · 2022 · cited 53× · PMID 35871712 · DOI 10.1007/s43440-022-00388-7
2. Paxlovid (Nirmatrelvir and Ritonavir) Use in Pregnant and Lactating Woman: Current Evidence and Practice Guidelines-A Scoping Review.
   Chourasia P, Maringanti BS, Edwards-Fligner M, Gangu K, et al · · 2023 · cited 18× · PMID 36679952 · DOI 10.3390/vaccines11010107
3. How to use COVID-19 antiviral drugs in patients with chronic kidney disease.
   Kale A, Shelke V, Dagar N, Anders HJ, et al · · 2023 · cited 14× · PMID 36843922 · DOI 10.3389/fphar.2023.1053814
4. Different drug approaches to COVID-19 treatment worldwide: an update of new drugs and drugs repositioning to fight against the novel coronavirus.
   Oliver JC, Silva EN, Soares LM, Scodeler GC, et al · · 2022 · cited 10× · PMID 36578829 · DOI 10.1177/25151355221144845
5. COVID-19 Therapeutics: An Update on Effective Treatments Against Infection With SARS-CoV-2 Variants.
   Padasas BT, Españo E, Kim SH, Song Y, et al · · 2023 · cited 7× · PMID 37179752 · DOI 10.4110/in.2023.23.e13