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Terminated

NCT Number: NCT05386472

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

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).

Why the study stopped: The trial prematurely terminated due to the inability to recruit the planned number of subjects. The decision to terminate the trial was not based on any safety concerns.
Terminated

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Key information

Conditions

COVID-19 Coronaviridae Infections Coronavirus Infections Infections Lung Diseases Nidovirales Infections Pneumonia Pneumonia, Viral RNA Virus Infections Respiratory Tract Diseases Respiratory Tract Infections Virus Diseases

Age range

18 year–50 year

Sex eligibility

Female

Study type

Interventional

Phase

Phase 1

Primary location

University of Alabama at Birmingham/Center for Women's Reproductive Health, Birmingham, Alabama, United States

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Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • All cohorts: Mild-to-moderate COVID-19 infection confirmed in sample collected ≤5 days prior to enrollment; onset within 5 days prior to enrollment and presence of ≥1 sign/symptom on the day of enrollment.
  • Cohorts 1&2: Expecting single baby; Pregnant in 2nd trimester, 14 0/7 to 27 6/7 weeks of gestational age (Cohort 1) or 3rd trimester, ≥28 0/7 and ≤34 6/7 weeks of gestational age (Cohort 2), by ultrasound.
  • All cohorts: Otherwise healthy participants who are determined by medical history, physical examination, and clinical judgment to be appropriate for inclusion in the study

Exclusion criteria

  • All cohorts: Current need for hospitalization or anticipated need for hospitalization in the clinical opinion of the site investigator.
  • Cohorts 1&2: Prior/current major condition or illness of mother/fetus substantially increasing risk of study participation/completion or impacting pregnancy/fetal outcomes in investigator's judgement.
  • All cohorts: Current use of any medications that are highly dependent on CYP3A4 for clearance, and which are contraindicated in combination with nirmatrelvir/ritonavir.
  • All cohorts: Has received or is expected to receive monoclonal antibody treatment, convalescent COVID-19 plasma, or anti-viral treatment (eg, molnupiravir) for the current SARSCoV-2 infection.
  • All cohorts: Participants with moderate to severe kidney impairment

Treatment and study plan

nirmatrelvir

Drug

Nirmatrelvir (tablets) administered by mouth every 12 hours for 5 days (10 doses total)

Other names: PF-07321332

Ritonavir

Drug

Ritonavir (capsules) administered by mouth every 12 hours for 5 days (10 doses total)

Primary outcomes

  1. Apparent Oral Clearance (CL/F)

    Time frame: Day 1: 1-3 hour post-dose; Day 3: 4-8 hour post-dose; Day 4: 8 to less than 12 hour post dose; Day 5: 2-4 hour, 6-8 hour, 10 to less than 12 hour post dose.

  2. Apparent Volume of Distribution (Vz/F)

    Time frame: Day 1: 1-3 hour post-dose; Day 3: 4-8 hour post-dose; Day 4: 8 to less than 12 hour post dose; Day 5: 2-4 hour, 6-8 hour, 10 to less than 12 hour post dose.

  3. Area Under the Curve From Time Zero to End of Dosing Interval (AUCtau)

    Time frame: Day 1: 1-3 hour post-dose; Day 3: 4-8 hour post-dose; Day 4: 8 to less than 12 hour post dose; Day 5: 2-4 hour, 6-8 hour, 10 to less than 12 hour post dose.

  4. Maximum Observed Plasma Concentration (Cmax)

    Time frame: Day 1: 1-3 hour post-dose; Day 3: 4-8 hour post-dose; Day 4: 8 to less than 12 hour post dose; Day 5: 2-4 hour, 6-8 hour, 10 to less than 12 hour post dose.

  5. Plasma Decay Half-Life (t1/2)

    Time frame: Day 1: 1-3 hour post-dose; Day 3: 4-8 hour post-dose; Day 4: 8 to less than 12 hour post dose; Day 5: 2-4 hour, 6-8 hour, 10 to less than 12 hour post dose.

  6. Observed Plasma Trough Concentration (Ctrough)

    Time frame: Day 1: 1-3 hour post-dose; Day 3: 4-8 hour post-dose; Day 4: 8 to less than 12 hour post dose; Day 5: 2-4 hour, 6-8 hour, 10 to less than 12 hour post dose.

  7. Incidence of Treatment Emergent Adverse Events (TEAEs)

    Time frame: Baseline up through Day 34

  8. Incidence of TEAEs, SAEs, and AEs leading to discontinuations

    Time frame: Baseline up through end of treatment (Day 5/Day 6)

Secondary outcomes

  1. Number of participants with delivery at medical facility

    Time frame: At delivery of the baby

  2. Number of participants with delivery at home

    Time frame: At delivery of the baby

  3. Number of participants with delivery at other location

    Time frame: At delivery of the baby

  4. Number of participants with caesarean section delivery

    Time frame: At delivery of the baby

  5. Number of participants with vaginal delivery

    Time frame: At delivery of the baby

  6. Number of participants with complications during delivery

    Time frame: At delivery of the baby

  7. Number of full-term live deliveries

    Time frame: At delivery of the baby

  8. Number of premature live deliveries

    Time frame: At delivery of the baby

  9. Number of participants with stillbirths

    Time frame: At delivery of the baby

  10. Number of participants with spontaneous abortions

    Time frame: At delivery of the baby

  11. Number of participants with induced/elective abortions

    Time frame: At delivery of the baby

  12. Number of participants with unknown delivery

    Time frame: At delivery of the baby

  13. Number of aborted or stillborn fetuses with abnormal findings upon gross visual inspection

    Time frame: At delivery of the baby

  14. Gestational age of newborn infants

    Time frame: At birth

  15. Number of neonates with congenital malformation/anomaly or other neonatal problem

    Time frame: At birth

  16. Body weight of newborn infants

    Time frame: At birth

  17. Body length of newborn infants

    Time frame: At birth

  18. Head circumference of newborn infants

    Time frame: At birth

  19. Incidence of SAEs in newborn infants

    Time frame: Birth through 24 hours after birth or until Study Day 34 (whichever is later)

Sponsors and collaborators

Lead sponsor

Pfizer

Industry

Registry information

Official study title

A PHASE 1, OPEN-LABEL STUDY TO EVALUATE THE PHARMACOKINETICS, SAFETY, AND TOLERABILITY OF ORALLY ADMINISTERED NIRMATRELVIR/RITONAVIR IN PREGNANT WOMEN WITH MILD-TO-MODERATE COVID-19

Important dates

Study start
2022
Primary completion
2025
Study completion
2025
First posted
May 23, 2022
Registry last updated
Aug 17, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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