A Study to Learn About the Medicine (PF-07321332 or Nirmatrelvir/Ritonavir) in Healthy Lactating Women
- Registration Number
- NCT05441215
- Lead Sponsor
- Pfizer
- 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.
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- Female
- Target Recruitment
- 8
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
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- SINGLE_GROUP
- Arm && Interventions
Group Intervention Description nirmatrelvir/ritonavir nirmatrelvir nirmatrelvir/ritonavir will be given by mouth two times a day as a tablet nirmatrelvir/ritonavir ritonavir nirmatrelvir/ritonavir will be given by mouth two times a day as a tablet
- Primary Outcome Measures
Name Time Method Maximum Breastmilk Concentration (Cmax) of nirmatrelvir 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) Time to Reach Maximum Breastmilk Concentration (Tmax) of nirmatrelvir 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) Area under the breastmilk concentration time profile from time 0 to the time of the end of the dosing interval (tau) of nirmatrelvir 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) Terminal phase half life (t½) of nirmatrelvir 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 clearance (CLbm) of nirmatrelvir 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) Average breastmilk concentration (Cav) of nirmatrelvir 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) Amount excreted in breast milk over the dosing interval (Aetau) of nirmatrelvir 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) Percent of dose excreted in breast milk during the dosing interval (Aetau %) of nirmatrelvir 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)
- Secondary Outcome Measures
Name Time Method Milk to plasma ratio (M/P) of both nirmatrelvir and ritonavir 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 ritonavir 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) t½ of ritonavir 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) Cav of ritonavir 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) Cmax of nirmatrelvir and ritonavir 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) Cav of nirmatrelvir and ritonavir 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) t½ of nirmatrelvir and ritonavir 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) Cmax of ritonavir 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) Tmax of ritonavir 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) Area under the breastmilk concentration time profile from time 0 to the time of the end of the dosing interval (Auc tau) of ritonavir 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) Aetau of ritonavir 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) Aetau % of ritonavir 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) CLbm of ritonavir 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) Pre-dose concentration (Ctrough) of nirmatrelvir and ritonavir 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) Tmax of nirmatrelvir and ritonavir 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) AUC tau of nirmatrelvir and ritonavir 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) Minimum Observed Breastmilk Concentration (Cmin) of nirmatrelvir and ritonavir 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) Apparent plasma clearance (CL/F) of nirmatrelvir and ritonavir 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) Body weight normalized infant dose in μg/kg/day (BWNID) of both nirmatrelvir and ritonavir 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) Participants reporting abnormal vital signs Baseline to 28 days after last dose Participants reporting abnormal electrocardiograms Baseline to 28 days after last dose Apparent volume of distribution (Vz/F) of nirmatrelvir and ritonavir 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) 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 (MPCmax during dosing interval tau) for both nirmatrelvir and ritonavir 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) Infant dose expressed as % of body weight normalized maternal dose (BWNIDPCM) of both nirmatrelvir and ritonavir 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) Participants reporting treatment emergent adverse events Baseline to 28 days after last dose Participants reporting abnormal clinical laboratory lab tests Baseline to 28 days after last dose CLbm for both nirmatrelvir and ritonavir 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) Body weight normalized maternal dose in μg/kg/day (BWNMD) of both nirmatrelvir and ritonavir 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) Participants reporting abnormal physical examination results Baseline to 28 days after last dose
Trial Locations
- Locations (1)
Pfizer Clinical Research Unit - Brussels
🇧🇪Brussels, Bruxelles-capitale, Région DE, Belgium