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A Study to Learn About the Medicine (PF-07321332 or Nirmatrelvir/Ritonavir) in Healthy Lactating Women

A PHASE I, MULTIPLE DOSE, OPEN-LABEL PHARMACOKINETIC STUDY OF NIRMATRELVIR/RITONAVIR IN HEALTHY LACTATING WOMEN

Status
Completed
Phases
Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT05441215
Enrollment
8
Registered
2022-07-01
Start date
2022-12-12
Completion date
2023-12-15
Last updated
2024-04-03

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Healthy Participants

Keywords

Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), Lactation, COVID-19, Breastfeeding, Protease Inhibitor

Brief summary

The main purpose of this study is to measure the level of active ingredient of the study medicine (nirmatrelvir) that is secreted in human breast milk when it is given to healthy breastfeeding women. The study medicine consists of two medicines, nirmatrelvir and ritonavir. We are seeking female participants who are: * Actively breast-feeding (lactating) at least 12 weeks postpartum; * Age between 18 to 55 years and not currently pregnant; * Have a Body Mass Index (BMI): 17.5 kg/m2; and a total body weight \>50 kg (110 lb). Participants will take the study medicine by mouth for a total of 3 times over 2 days (2 morning doses and 1 evening dose) at the study clinic. We will periodically collect breast milk from day 2 to 4 to measure the level of nirmatrelvir and ritonavir in it. A safety follow up call will be conducted around 28-35 days from the last dose to monitor any reactions participants may have to the study medicine.

Interventions

nirmatrelvir/ritonavir

DRUGritonavir

nirmatrelvir/ritonavir

Sponsors

Pfizer
Lead SponsorINDUSTRY

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
OTHER
Masking
NONE

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 55 Years
Healthy volunteers
Yes

Inclusion criteria

* Healthy lactating females who are actively breast-feeding or expressing breast milk, at least 12 weeks post-partum and not currently pregnant between 18 and 55 years old * Body Mass Index (BMI): 17.5 kg/m2; and a total body weight \>50 kg (110 lb) * Infants of women enrolled in the study must be able to feed successfully from a bottle or other age-appropriate alternative feeding method prior to the start of the study and must be able to tolerate infant formula if the mother does not have a supply of stored breast milk sufficient to cover the duration of the study * Participants must be willing to temporarily discontinue breast feeding their infants for a total of 4.5 days (108 hours) * Participants must be willing to regularly pump breasts throughout the study and express milk according to a schedule designed to maintain lactation throughout the study period

Exclusion criteria

* Positive test result (RT-PCR) for SARS-CoV-2 infection at the time of screening or Day -1 * Evidence or history of clinically significant findings * History of febrile illness or mastitis within 5 days prior to the first dose of study medication * Participants who have received a COVID-19 vaccine within 7 days before screening or admission, or who are to be vaccinated with a COVID-19 vaccine at any time during the study confinement period * History of HIV infection, hepatitis B, or hepatitis C; positive testing for HIV, HBsAg, or HCVAb. Hepatitis B vaccination is allowed * Abnormal vital signs such as blood pressure, 12-lead electrocardiogram * History of alcohol abuse and/or illicit drug use, tobacco use in excess of 5 cigarettes/day or 2 chews/day * Blood donation within 60 days

Design outcomes

Primary

MeasureTime frame
Maximum Breastmilk Concentration (Cmax) of nirmatrelvirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Time to Reach Maximum Breastmilk Concentration (Tmax) of nirmatrelvirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Area under the breastmilk concentration time profile from time 0 to the time of the end of the dosing interval (tau) of nirmatrelvirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Terminal phase half life (t½) of nirmatrelvirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Average breastmilk concentration (Cav) of nirmatrelvirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Amount excreted in breast milk over the dosing interval (Aetau) of nirmatrelvirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Percent of dose excreted in breast milk during the dosing interval (Aetau %) of nirmatrelvirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Breast milk clearance (CLbm) of nirmatrelvirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)

Secondary

MeasureTime frame
CLbm of ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Cmax of nirmatrelvir and ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Cav of nirmatrelvir and ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Pre-dose concentration (Ctrough) of nirmatrelvir and ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Tmax of nirmatrelvir and ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
AUC tau of nirmatrelvir and ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Minimum Observed Breastmilk Concentration (Cmin) of nirmatrelvir and ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
t½ of nirmatrelvir and ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Apparent volume of distribution (Vz/F) of nirmatrelvir and ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Daily (24 hour) amount of nirmatrelvir excreted in breast milk (Ae 24bm)Day 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Breast milk to plasma ratio for AUC tau (MPAUC tau) for both nirmatrelvir and ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Cmax of ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
CLbm for both nirmatrelvir and ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Milk to plasma ratio (M/P) of both nirmatrelvir and ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Body weight normalized infant dose in μg/kg/day (BWNID) of both nirmatrelvir and ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Body weight normalized maternal dose in μg/kg/day (BWNMD) of both nirmatrelvir and ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Infant dose expressed as % of body weight normalized maternal dose (BWNIDPCM) of both nirmatrelvir and ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Participants reporting treatment emergent adverse eventsBaseline to 28 days after last dose
Participants reporting abnormal clinical laboratory lab testsBaseline to 28 days after last dose
Participants reporting abnormal vital signsBaseline to 28 days after last dose
Participants reporting abnormal physical examination resultsBaseline to 28 days after last dose
Participants reporting abnormal electrocardiogramsBaseline to 28 days after last dose
Breast milk to plasma ratio for AUC tau (MPCmax during dosing interval tau) for both nirmatrelvir and ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Tmax of ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Apparent plasma clearance (CL/F) of nirmatrelvir and ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Area under the breastmilk concentration time profile from time 0 to the time of the end of the dosing interval (Auc tau) of ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
t½ of ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Cav of ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Aetau of ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)
Aetau % of ritonavirDay 2 (0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12 hours) and Day 3 (18, 24, 32, 40 hours) Day 4 (48 hours)

Countries

Belgium

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026