Trial Outcomes & Findings for A Study to Learn About the Medicine (PF-07321332 or Nirmatrelvir/Ritonavir) in Healthy Lactating Women (NCT NCT05441215)

NCT ID: NCT05441215

Last Updated: 2026-05-01

Results Overview

The percent of nirmatelvir excreted in breast milk to amount of breast milk over the dosing interval .

Recruitment status

COMPLETED

Study phase

PHASE1

Target enrollment

8 participants

Primary outcome timeframe

At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Results posted on

2026-05-01

Participant Flow

Eleven participants were screened, of which 3 failed at screening. All the 8 participants who met the eligibility criteria were enrolled and assigned to the study treatment and treated with Nirmatrelvir 300 mg and Ritonavir 100 mg.

Participant milestones

Participant milestones
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Overall Study
STARTED
8
Overall Study
COMPLETED
8
Overall Study
NOT COMPLETED
0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

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

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Age, Continuous
33.50 Years
STANDARD_DEVIATION 6.14 • n=14 Participants
Sex: Female, Male
Female
8 Participants
n=14 Participants
Sex: Female, Male
Male
0 Participants
n=14 Participants
Ethnicity (NIH/OMB)
Hispanic or Latino
0 Participants
n=14 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
8 Participants
n=14 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
n=14 Participants
Race/Ethnicity, Customized
Race: White
8 Participants
n=14 Participants

PRIMARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The maximum observed concentration and was directly observed from data.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
The Maximum Observed Concentration of Nirmatrelvir in Breast Milk Over the Dosing Interval
1904 Nanograms / milliliter (ng/mL)
Geometric Coefficient of Variation 33

PRIMARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Cmax was defined as maximum observed concentration of nirmatrelvir in breast milk.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Time to Reach Cmax of Nirmatrelvir in Breast Milk
3.22 Hour
Interval 3.22 to 6.22

PRIMARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Area under the concentration curve for nirmatrelvir in breast milk from time 0 to end of dosing interval.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Area Under the Concentration-Time Profile From Time Zero to End of Dosing Interval for Nirmatrelvir in Breast Milk
12770 Nanograms*hour / milliliter (ng*hr/mL)
Geometric Coefficient of Variation 36

PRIMARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The time measured for the breast milk nirmatrelvir concentration to decrease by one half.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Terminal Half-Life of Nirmatrelvir in Breast Milk
4.455 Hour
Standard Deviation 0.68964

PRIMARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The average concentration across time and can be calculated by dividing AUCtau by time. AUCtau was defined area under the concentration curve from time 0 to end of dosing interval.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
The Average Steady State Concentration of Nirmatrelvir in Breast Milk
1063 ng/mL
Geometric Coefficient of Variation 36

PRIMARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The amount of nirmatrelvir excreted into breast milk over the dosing interval.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
The Amount of Nirmatrelvir Excreted in Breast Milk Over the Dosing Interval Tau
0.3758 Milligram (mg)
Geometric Coefficient of Variation 45

PRIMARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The percent of nirmatelvir excreted in breast milk to amount of breast milk over the dosing interval .

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
The Percent of Amount of Nirmatrelvir Excreted in Breast Milk Over The Dosing Interval Tau
0.1253 Percentage of dose
Geometric Coefficient of Variation 45

PRIMARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Clearance was defined as the apparent volume (Liter) of breast milk completely cleared the nirmatrelvir per hour.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Breast Milk Clearance of Nirmatrelvir
0.007641 Liter/hour (L/hr)
Geometric Coefficient of Variation 26

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The maximum observed concentration and was directly observed from data.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
The Maximum Observed Concentration of Ritonavir in Breast Milk Observed Over the Dosing Interval
71.99 ng/mL
Geometric Coefficient of Variation 66

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Cmax was defined as maximum observed concentration of ritonavir in breast milk.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Time to Reach Cmax of Ritonavir in Breast Milk
3.17 Hour
Interval 3.17 to 6.17

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Area under the concentration curve for ritonavir in breast milk from time 0 to end of dosing interval.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Area Under the Concentration-Time Profile for Ritonavir in Breast Milk From Time Zero to End of Dosing Interval
456.8 ng*hr/mL
Geometric Coefficient of Variation 47

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The time measured for the breast milk ritonavir concentration to decrease by one half.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=1 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Half-Life of Ritonavir in Breast Milk
NA Hour
Standard Deviation NA
As was pre-specified in the study protocol, summary statistics were not presented if fewer than 3 participants had reportable parameter values. Half-life of ritonavir in breast milk reported for a single participant was 4.07 hour.

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The average concentration across time and can be calculated by dividing AUCtau by time. AUCtau was defined area under the concentration curve from time 0 to end of dosing interval.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
The Average Steady State Concentration of Ritonavir in Breast Milk
38.08 ng/mL
Geometric Coefficient of Variation 47

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The amount of ritonavir excreted into breast milk over the dosing interval.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
The Amount of Ritonavir Excreted in Breast Milk Over the Dosing Interval Tau
0.01354 mg
Geometric Coefficient of Variation 56

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The percent of ritonavir excreted in breast milk to amount of breast milk over the dosing interval.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
The Percent of Ritonavir Excreted in Breast Milk Over The Dosing Interval Tau
0.01354 Percentage of dose
Geometric Coefficient of Variation 56

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Clearance was defined as the apparent volume (L) of breast milk completely cleared the ritonavir per hour.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Breast Milk Clearance of Ritonavir
0.001966 L/hr
Geometric Coefficient of Variation 30

SECONDARY outcome

Timeframe: At 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48 Hours Post Dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The maximum observed concentration and was directly observed from data.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
The Maximum Observed Concentration of Nirmatrelvir in Plasma Observed Over the Dosing Interval
7080 ng/mL
Geometric Coefficient of Variation 17

SECONDARY outcome

Timeframe: At 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48 Hours Post Dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The maximum observed concentration and was directly observed from data.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
The Maximum Observed Concentration of Ritonavir in Plasma Observed Over the Dosing Interval
1228 ng/mL
Geometric Coefficient of Variation 48

SECONDARY outcome

Timeframe: At 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48 Hours Post Dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Area under the concentration curve for nirmatrelvir in breast milk from time 0 to end of dosing interval.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Area Under the Concentration-Time Profile for Nirmatrelvir in Plasma From Time Zero to End of Dosing Interval
49190 ng*hr/mL
Geometric Coefficient of Variation 21

SECONDARY outcome

Timeframe: At 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48 Hours Post Dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Area under the concentration curve for ritonavir in plasma from time 0 to end of dosing interval.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Area Under the Concentration-Time Profile for Ritonavir in Plasma From Time Zero to End of Dosing Interval
6893 ng*hr/mL
Geometric Coefficient of Variation 31

SECONDARY outcome

Timeframe: At 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48 Hours Post Dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The time measured for the plasma nirmatrelvir concentration to decrease by one half.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Half-Life of Nirmatrelvir in Plasma
7.180 Hour
Standard Deviation 1.3299

SECONDARY outcome

Timeframe: At 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48 Hours Post Dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The time measured for the plasma ritonavir concentration to decrease by one half.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Half-Life of Ritonavir in Plasma
5.190 Hour
Standard Deviation 0.79075

SECONDARY outcome

Timeframe: At 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48 Hours Post Dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The minimum observed concentration and was directly observed from data.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
The Minimum Plasma Concentration of Nirmatrelvir Observed Over the Dosing Interval
1240 ng/mL
Geometric Coefficient of Variation 32

SECONDARY outcome

Timeframe: At 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48 Hours Post Dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The minimum observed concentration and was directly observed from data.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
The Minimum Plasma Concentration of Ritonavir Observed Over the Dosing Interval
136.9 ng/mL
Geometric Coefficient of Variation 20

SECONDARY outcome

Timeframe: At 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48 Hours Post Dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Cmax was defined as maximum observed concentration of nirmatrelvir in plasma.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Time to Reach Cmax of Nirmatrelvir in Plasma
3.56 Hour
Interval 1.08 to 4.07

SECONDARY outcome

Timeframe: At 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48 Hours Post Dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Cmax was defined as maximum observed concentration of ritonavir in plasma.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Time to Reach Cmax of Ritonavir in Plasma
4.03 Hour
Interval 2.0 to 6.0

SECONDARY outcome

Timeframe: At 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48 Hours Post Dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Clearance was defined as the apparent volume (L) of plasma completely cleared the nirmatrelvir per hour.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Apparent Clearance of Nirmatrelvir From Plasma
6.099 L/hour
Geometric Coefficient of Variation 21

SECONDARY outcome

Timeframe: At 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48 Hours Post Dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Clearance was defined as the apparent volume (L) of plasma completely cleared the ritonavir per hour.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Apparent Clearance of Ritonavir From Plasma
14.50 L/hour
Geometric Coefficient of Variation 31

SECONDARY outcome

Timeframe: At 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48 Hours Post Dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Volume of distribution was defined as the theoretical volume in which the total amount of drug would need to be uniformly distributed to produce the desired plasma concentration of a drug. Apparent volume of distribution after oral dose was influenced by the fraction absorbed.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Apparent Volume of Nirmatrelvir Distribution
62.16 L
Geometric Coefficient of Variation 24

SECONDARY outcome

Timeframe: At 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48 Hours Post Dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Volume of distribution was defined as the theoretical volume in which the total amount of drug would need to be uniformly distributed to produce the desired plasma concentration of a drug. Apparent volume of distribution after oral dose was influenced by the fraction absorbed.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Apparent Volume of Ritonavir Distribution
107.5 L
Geometric Coefficient of Variation 41

SECONDARY outcome

Timeframe: At 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48 Hours Post Dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The average concentration across time and can be calculated by dividing AUCtau by time. AUCtau was defined area under the concentration curve from time 0 to end of dosing interval.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
The Average Steady State Concentration of Nirmatrelvir in Plasma
4098 ng/mL
Geometric Coefficient of Variation 21

SECONDARY outcome

Timeframe: At 0, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 18, 24, 32, 40, 48 Hours Post Dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The average concentration across time and can be calculated by dividing AUCtau by time. AUCtau was defined area under the concentration curve from time 0 to end of dosing interval.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
The Average Steady State Concentration of Ritonavir in Plasma
574.5 ng/mL
Geometric Coefficient of Variation 31

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Amount of nirmatrelvir excreted in breast milk in 24 hours.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Daily (24 Hour) Amount of Nirmatrelvir Excreted in Breast Milk
0.7520 mg/day
Geometric Coefficient of Variation 45

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Amount of ritonavir excreted in breast milk in 24 hours.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Daily (24 Hour) Amount of Ritonavir Excreted in Breast Milk
0.02709 mg/day
Geometric Coefficient of Variation 56

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The ratio of area under the concentration-time profile for nirmatrelvir in milk to those in plasma from time zero to end of dosing interval.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Milk to Plasma Ratio of Nirmatrelvir for AUCtau During Dosing Interval
0.2596 Ratio
Geometric Coefficient of Variation 26

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The ratio of area under the concentration-time profile for ritonavir in milk to those in plasma from time zero to end of dosing interval.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Milk to Plasma Ratio of Ritonavir for AUCtau During Dosing Interval
0.06626 Ratio
Geometric Coefficient of Variation 21

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The ratio of the maximum concentration of nirmatrelvir in breast milk to those in plasma observed over the dosing interval.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Milk to Plasma Ratio of Nirmatrelvir for Cmax During Dosing Interval
0.2689 Ratio
Geometric Coefficient of Variation 23

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

The ratio of the maximum concentration of ritonavir in breast milk to those in plasma observed over the dosing interval.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Milk to Plasma Ratio of Ritonavir for Cmax During Dosing Interval
0.05860 Ratio
Geometric Coefficient of Variation 35

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

BWNID = MPAUCtau \* Cav \* 150 mL/kg/day, where 150 mL/kg/day\^2 is the standardized milk consumption for an infant. MPAUCtau: Milk to plasma ratio for AUCtau. Cav: Average concentration.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Body Weight Normalized Infant Dose (BWNID) of Nirmatrelvir in mg/kg/Day
0.1595 mg/kg/day
Geometric Coefficient of Variation 36

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

BWNID = MPAUCtau \* Cav \* 150 mL/kg/day, where 150 mL/kg/day\^2 is the standardized milk consumption for an infant. MPAUCtau: Milk to plasma ratio for AUCtau. Cav: Average concentration.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
BWNID of Ritonavir in mg/kg/Day
0.005709 mg/kg/day
Geometric Coefficient of Variation 47

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Maternal dose in mg/day (300 mg BID = 600 mg/day for nirmatrelvir and 100 mg BID = 200 mg/day for ritonavir) / maternal weight in kg at screening.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Body Weight Normalized Maternal Dose (BWNMD) of Nirmatrelvir in mg/kg/Day
8.969 mg/kg/day
Geometric Coefficient of Variation 22

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

Maternal dose in mg/day (300 mg BID = 600 mg/day for nirmatrelvir and 100 mg BID = 200 mg/day for ritonavir) / maternal weight in kg at screening.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
BWNMD of Ritonavir in mg/kg/Day
2.990 mg/kg/day
Geometric Coefficient of Variation 23

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

BWNIDPCM = 100 \* BWNID / BWNMD.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Infant Dose Expressed As % of Body Weight Normalized Maternal Dose (BWNIDPCM) for Nirmatrelvir
1.779 Percentage of dose
Geometric Coefficient of Variation 27

SECONDARY outcome

Timeframe: At Day -1 (24 Hours Prior to Dosing on Day 1), Pre-dose on Day 1, 0 to 2, 2 to 4, 4 to 8, 8 to 12, 12 to 24, 24 to 32, 32 to 40 and 40 to 48 Hours Post-dose on Day 2

Population: The PK parameter analysis population was defined as all participants assigned to study intervention and who took at least 1 dose of nirmatrelvir/ritonavir and in whom at least 1 of the PK parameters of interest was reported.

BWNIDPCM = 100 \* BWNID / BWNMD.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
BWNIDPCM for Ritonavir
0.1910 Percentage of dose
Geometric Coefficient of Variation 42

SECONDARY outcome

Timeframe: From the first dose of study treatment on Day 1 to up to 28 days after the last dose of study intervention on Day 2 (maximum to 30 days)

Population: All participants randomly assigned to study intervention and who took at least 1 dose of study intervention. Participants were analyzed according to the product they actually received.

An adverse event (AE) was any untoward medical occurrence in a participant or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. AEs might arise from symptoms or other complaints reported to the investigator by the participant (or, when appropriate, by a caregiver, surrogate, or the participant's legally authorized representative), or they might arise from clinical findings of the investigator or other healthcare providers (clinical signs, test results, etc.). TEAEs were those with initial onset or increasing in severity after the first dose of study treatment.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Number of Participants With Treatment Emergent Adverse Events
8 Participants

SECONDARY outcome

Timeframe: At Screening (Day -28 to Day -2), Day -1, and Day 4

Population: All participants randomly assigned to study intervention and who took at least 1 dose of study intervention. Participants were analyzed according to the product they actually received.

The laboratory abnormality parameters included urinalysis: urine bilirubin (\>=1), urine hemoglobin (\>=1) and leukocyte esterase (\>=1).

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Number of Participants With Laboratory Abnormalities (Without Regard to Baseline Abnormality)
Urine Bilirubin >=1
1 Participants
Number of Participants With Laboratory Abnormalities (Without Regard to Baseline Abnormality)
Urine Hemoglobin >=1
1 Participants
Number of Participants With Laboratory Abnormalities (Without Regard to Baseline Abnormality)
Leukocyte Esterase >=1
3 Participants

SECONDARY outcome

Timeframe: At Screening (Day -28 to Day -2), Pre-dose and 12 Hours post-dose on Day 1, Pre-dose and 48 Hours Post-dose on Day 2

Population: All participants randomly assigned to study intervention and who took at least 1 dose of study intervention. Participants were analyzed according to the product they actually received.

Single supine blood pressure (BP), and pulse rate (PR) were performed following approximately a 5-minute rest in a supine position. BP, and PR assessments will be performed after collection of electrocardiogram (ECGs) and prior to collection of blood draws if scheduled at the same time. Vital signs abnormality included supine systolic BP \<90mmHg.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Number of Participants With Vital Signs Abnormalities
1 Participants

SECONDARY outcome

Timeframe: At Screening (from Day -28 to Day -2)

Population: All participants randomly assigned to study intervention and who took at least 1 dose of study intervention. Participants were analyzed according to the product they actually received.

Standard 12-lead ECGs utilizing limb leads (with a 10 second rhythm strip) were collected. All ECG assessments were made after at least a 5-minute rest in a supine position and prior to any blood draws or vital sign measurements.

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Number of Participants With ECG Abnormalities
0 Participants

SECONDARY outcome

Timeframe: At Screening (from Day -28 to Day -2) or Day -1

Population: All participants randomly assigned to study intervention and who took at least 1 dose of study intervention. Participants were analyzed according to the product they actually received.

Physical examination included height, weight and body mass index (BMI, BMI = weight \[kg\] / height \[m\^2\]) obtained for eligibility criteria. Physical examination abnormalities: BMI \<17.5 kg/m\^2; and a total body weight \<=50 kg (110 lb).

Outcome measures

Outcome measures
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 Participants
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Number of Participants With Physical Examination Abnormalities
0 Participants

Adverse Events

Nirmatrelvir 300 mg + Ritonavir 100 mg

Serious events: 0 serious events
Other events: 8 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure
Nirmatrelvir 300 mg + Ritonavir 100 mg
n=8 participants at risk
Healthy lactating female who took nirmatrelvir 300 mg and ritonavir 100 mg for 3 doses (at 0, 12 hours post dose on Day 1, and 0 hours on Day 2, respectively)
Gastrointestinal disorders
Abdominal pain
25.0%
2/8 • From From the first dose of study treatment on Day 1 to up to 28 days after the last dose of study intervention on Day 2 (maximum to 30 days).
The same event may appear as both an AE and an SAE. An event may be categorized as serious in 1 participant and as non-serious in another participant, or 1 participant may have experienced both a serious and non-serious event during the study. Total number at risk below refers to the number of participants evaluable for SAEs or AEs.
Gastrointestinal disorders
Diarrhoea
12.5%
1/8 • From From the first dose of study treatment on Day 1 to up to 28 days after the last dose of study intervention on Day 2 (maximum to 30 days).
The same event may appear as both an AE and an SAE. An event may be categorized as serious in 1 participant and as non-serious in another participant, or 1 participant may have experienced both a serious and non-serious event during the study. Total number at risk below refers to the number of participants evaluable for SAEs or AEs.
General disorders
Vessel puncture site reaction
37.5%
3/8 • From From the first dose of study treatment on Day 1 to up to 28 days after the last dose of study intervention on Day 2 (maximum to 30 days).
The same event may appear as both an AE and an SAE. An event may be categorized as serious in 1 participant and as non-serious in another participant, or 1 participant may have experienced both a serious and non-serious event during the study. Total number at risk below refers to the number of participants evaluable for SAEs or AEs.
Nervous system disorders
Dizziness
12.5%
1/8 • From From the first dose of study treatment on Day 1 to up to 28 days after the last dose of study intervention on Day 2 (maximum to 30 days).
The same event may appear as both an AE and an SAE. An event may be categorized as serious in 1 participant and as non-serious in another participant, or 1 participant may have experienced both a serious and non-serious event during the study. Total number at risk below refers to the number of participants evaluable for SAEs or AEs.
Nervous system disorders
Dysgeusia
87.5%
7/8 • From From the first dose of study treatment on Day 1 to up to 28 days after the last dose of study intervention on Day 2 (maximum to 30 days).
The same event may appear as both an AE and an SAE. An event may be categorized as serious in 1 participant and as non-serious in another participant, or 1 participant may have experienced both a serious and non-serious event during the study. Total number at risk below refers to the number of participants evaluable for SAEs or AEs.
Nervous system disorders
Headache
25.0%
2/8 • From From the first dose of study treatment on Day 1 to up to 28 days after the last dose of study intervention on Day 2 (maximum to 30 days).
The same event may appear as both an AE and an SAE. An event may be categorized as serious in 1 participant and as non-serious in another participant, or 1 participant may have experienced both a serious and non-serious event during the study. Total number at risk below refers to the number of participants evaluable for SAEs or AEs.
Respiratory, thoracic and mediastinal disorders
Oropharyngeal pain
12.5%
1/8 • From From the first dose of study treatment on Day 1 to up to 28 days after the last dose of study intervention on Day 2 (maximum to 30 days).
The same event may appear as both an AE and an SAE. An event may be categorized as serious in 1 participant and as non-serious in another participant, or 1 participant may have experienced both a serious and non-serious event during the study. Total number at risk below refers to the number of participants evaluable for SAEs or AEs.
Gastrointestinal disorders
Food poisoning
12.5%
1/8 • From From the first dose of study treatment on Day 1 to up to 28 days after the last dose of study intervention on Day 2 (maximum to 30 days).
The same event may appear as both an AE and an SAE. An event may be categorized as serious in 1 participant and as non-serious in another participant, or 1 participant may have experienced both a serious and non-serious event during the study. Total number at risk below refers to the number of participants evaluable for SAEs or AEs.
Gastrointestinal disorders
Nausea
12.5%
1/8 • From From the first dose of study treatment on Day 1 to up to 28 days after the last dose of study intervention on Day 2 (maximum to 30 days).
The same event may appear as both an AE and an SAE. An event may be categorized as serious in 1 participant and as non-serious in another participant, or 1 participant may have experienced both a serious and non-serious event during the study. Total number at risk below refers to the number of participants evaluable for SAEs or AEs.
Reproductive system and breast disorders
Breast pain
12.5%
1/8 • From From the first dose of study treatment on Day 1 to up to 28 days after the last dose of study intervention on Day 2 (maximum to 30 days).
The same event may appear as both an AE and an SAE. An event may be categorized as serious in 1 participant and as non-serious in another participant, or 1 participant may have experienced both a serious and non-serious event during the study. Total number at risk below refers to the number of participants evaluable for SAEs or AEs.
Reproductive system and breast disorders
Dysmenorrhoea
12.5%
1/8 • From From the first dose of study treatment on Day 1 to up to 28 days after the last dose of study intervention on Day 2 (maximum to 30 days).
The same event may appear as both an AE and an SAE. An event may be categorized as serious in 1 participant and as non-serious in another participant, or 1 participant may have experienced both a serious and non-serious event during the study. Total number at risk below refers to the number of participants evaluable for SAEs or AEs.
Reproductive system and breast disorders
Heavy menstrual bleeding
12.5%
1/8 • From From the first dose of study treatment on Day 1 to up to 28 days after the last dose of study intervention on Day 2 (maximum to 30 days).
The same event may appear as both an AE and an SAE. An event may be categorized as serious in 1 participant and as non-serious in another participant, or 1 participant may have experienced both a serious and non-serious event during the study. Total number at risk below refers to the number of participants evaluable for SAEs or AEs.

Additional Information

Pfizer ClinicalTrials.gov Call Center

Pfizer, Inc.

Phone: 1-800-718-1021

Results disclosure agreements

  • Principal investigator is a sponsor employee Pfizer has the right to review disclosures, requesting a delay of less than 60 days. Investigator will postpone single center publications until after disclosure of pooled data (all sites), less than 12 months from study completion/termination at all participating sites. Investigator may not disclose previously undisclosed confidential information other than study results.
  • Publication restrictions are in place

Restriction type: OTHER