Trial Outcomes & Findings for Drug-Drug Interaction Study to Estimate the Effect of PF-07321332/Ritonavir and Ritonavir on Midazolam in Healthy Participants (NCT NCT05032950)

NCT ID: NCT05032950

Last Updated: 2023-10-04

Results Overview

Cmax for midazolam following single dose administration with and without PF-07321332/ritonavir was observed directly from data. Natural log-transformed Cmax for Midazolam were analyzed using a mixed effect model with sequence, period and treatment as fixed effects and participant within sequence as a random effect. The ratios (PF-07321332/ritonavir + midazolam \[test\]/midazolam \[reference\] and 90% CIs) were expressed as percentages.

Recruitment status

COMPLETED

Study phase

PHASE1

Target enrollment

12 participants

Primary outcome timeframe

Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam+PF-07321332/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose

Results posted on

2023-10-04

Participant Flow

A total of 12 healthy participants were randomized to receive midazolam, PF-07321332/ritonavir + midazolam, and ritonavir + midazolam in a total of 6 sequences.

Participant milestones

Participant milestones
Measure
Treatment Sequence 1
Period 1: Treatment A: Midazolam Single dose of 2 mg midazolam was administered orally on Day 1, followed by serial PK sampling and 2-day washout (Duration: Day 1 to Day 3). Period 2: Treatment B: PF-07321332/Ritonavir + Midazolam PF-07321332 300 mg/ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12). Period 3: Treatment C: Ritonavir + Midazolam Ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Treatment Sequence 2
Period 1: Treatment C: Ritonavir + Midazolam Ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12). Period 2: Treatment A: Midazolam Single dose of 2 mg midazolam was administered orally on Day 1, followed by serial PK sampling and 2-day washout (Duration: Day 1 to Day 3). Period 3: Treatment B: PF-07321332/Ritonavir + Midazolam PF-07321332 300 mg/ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Treatment Sequence 3
Period 1: Treatment B: PF-07321332/Ritonavir + Midazolam PF-07321332 300 mg/ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12). Period 2: Treatment C: Ritonavir + Midazolam Ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12). Period 3: Treatment A: Midazolam Single dose of 2 mg midazolam was administered orally on Day 1, followed by serial PK sampling and 2-day washout (Duration: Day 1 to Day 3).
Treatment Sequence 4
Period 1: Treatment C: Ritonavir + Midazolam Ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12). Period 2: Treatment B: PF-07321332/Ritonavir + Midazolam PF-07321332 300 mg/ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12). Period 3: Treatment A: Midazolam Single dose of 2 mg midazolam administered orally on Day 1, followed by serial PK sampling and 2-day washout (Duration: Day 1 to Day 3).
Treatment Sequence 5
Period 1: Treatment B: PF-07321332/Ritonavir + Midazolam PF-07321332 300 mg/ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12). Period 2: Treatment A: Midazolam Single dose of 2 mg midazolam was administered orally on Day 1, followed by serial PK sampling and 2-day washout (Duration: Day 1 to Day 3). Period 3: Treatment C: Ritonavir + Midazolam Ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Treatment Sequence 6
Period 1: Treatment A: Midazolam Single dose of 2 mg midazolam was administered orally on Day 1, followed by serial PK sampling and 2-day washout (Duration: Day 1 to Day 3). Period 2: Treatment C: Ritonavir + Midazolam Ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12). Period 3: Treatment B: PF-07321332/Ritonavir + Midazolam PF-07321332 300 mg/ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Overall Study
STARTED
2
2
2
2
2
2
Overall Study
COMPLETED
2
2
1
1
2
2
Overall Study
NOT COMPLETED
0
0
1
1
0
0

Reasons for withdrawal

Reasons for withdrawal
Measure
Treatment Sequence 1
Period 1: Treatment A: Midazolam Single dose of 2 mg midazolam was administered orally on Day 1, followed by serial PK sampling and 2-day washout (Duration: Day 1 to Day 3). Period 2: Treatment B: PF-07321332/Ritonavir + Midazolam PF-07321332 300 mg/ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12). Period 3: Treatment C: Ritonavir + Midazolam Ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Treatment Sequence 2
Period 1: Treatment C: Ritonavir + Midazolam Ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12). Period 2: Treatment A: Midazolam Single dose of 2 mg midazolam was administered orally on Day 1, followed by serial PK sampling and 2-day washout (Duration: Day 1 to Day 3). Period 3: Treatment B: PF-07321332/Ritonavir + Midazolam PF-07321332 300 mg/ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Treatment Sequence 3
Period 1: Treatment B: PF-07321332/Ritonavir + Midazolam PF-07321332 300 mg/ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12). Period 2: Treatment C: Ritonavir + Midazolam Ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12). Period 3: Treatment A: Midazolam Single dose of 2 mg midazolam was administered orally on Day 1, followed by serial PK sampling and 2-day washout (Duration: Day 1 to Day 3).
Treatment Sequence 4
Period 1: Treatment C: Ritonavir + Midazolam Ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12). Period 2: Treatment B: PF-07321332/Ritonavir + Midazolam PF-07321332 300 mg/ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12). Period 3: Treatment A: Midazolam Single dose of 2 mg midazolam administered orally on Day 1, followed by serial PK sampling and 2-day washout (Duration: Day 1 to Day 3).
Treatment Sequence 5
Period 1: Treatment B: PF-07321332/Ritonavir + Midazolam PF-07321332 300 mg/ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12). Period 2: Treatment A: Midazolam Single dose of 2 mg midazolam was administered orally on Day 1, followed by serial PK sampling and 2-day washout (Duration: Day 1 to Day 3). Period 3: Treatment C: Ritonavir + Midazolam Ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Treatment Sequence 6
Period 1: Treatment A: Midazolam Single dose of 2 mg midazolam was administered orally on Day 1, followed by serial PK sampling and 2-day washout (Duration: Day 1 to Day 3). Period 2: Treatment C: Ritonavir + Midazolam Ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12). Period 3: Treatment B: PF-07321332/Ritonavir + Midazolam PF-07321332 300 mg/ritonavir 100 mg was administered orally every 12 hours for a total of 9 doses on Days 1-5 and a single oral dose of midazolam 2 mg was administered on Day 5 followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Overall Study
Adverse Event
0
0
1
1
0
0

Baseline Characteristics

Drug-Drug Interaction Study to Estimate the Effect of PF-07321332/Ritonavir and Ritonavir on Midazolam in Healthy Participants

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
All Participants
n=12 Participants
All participants enrolled in this study
Age, Continuous
Mean (SD)
34.6 Years
STANDARD_DEVIATION 9.26 • n=93 Participants
Age, Customized
<18 Years
0 Participants
n=93 Participants
Age, Customized
18-25 Years
2 Participants
n=93 Participants
Age, Customized
26-35 Years
4 Participants
n=93 Participants
Age, Customized
36-45 Years
4 Participants
n=93 Participants
Age, Customized
>45 Years
2 Participants
n=93 Participants
Sex: Female, Male
Female
1 Participants
n=93 Participants
Sex: Female, Male
Male
11 Participants
n=93 Participants
Race/Ethnicity, Customized
White
9 Participants
n=93 Participants
Race/Ethnicity, Customized
Black or African American
1 Participants
n=93 Participants
Race/Ethnicity, Customized
Asian
2 Participants
n=93 Participants
Race/Ethnicity, Customized
Hispanic or Latino
2 Participants
n=93 Participants
Race/Ethnicity, Customized
Not Hispanic or Latino
10 Participants
n=93 Participants

PRIMARY outcome

Timeframe: Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam+PF-07321332/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose

Population: The PK parameter analysis population was defined as all participants randomized and treated who had at least 1 of the PK parameters of primary interest in at least 1 treatment period.

Cmax for midazolam following single dose administration with and without PF-07321332/ritonavir was observed directly from data. Natural log-transformed Cmax for Midazolam were analyzed using a mixed effect model with sequence, period and treatment as fixed effects and participant within sequence as a random effect. The ratios (PF-07321332/ritonavir + midazolam \[test\]/midazolam \[reference\] and 90% CIs) were expressed as percentages.

Outcome measures

Outcome measures
Measure
Midazolam 2 mg
n=10 Participants
Midazolam administered as a single dose on Day 1
PF-07321332 300 mg/Ritonavir 100 mg + Midazolam 2 mg
n=10 Participants
PF-07321332/ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Ritonavir 100 mg + Midazolam 2 mg
Participants administer Ritonavir orally every 12 hours for a total of 9 doses on Day1-5 and Midazolam orally as a single dose on Day 5, followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Maximum Plasma Concentration (Cmax) of Midazolam When Administered Alone and With PF-07321332/Ritonavir
9.812 ng/mL
Geometric Coefficient of Variation 38
36.18 ng/mL
Geometric Coefficient of Variation 17

PRIMARY outcome

Timeframe: Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam+PF-07321332/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose

Population: The PK parameter analysis population was defined as all participants randomized and treated who had at least 1 of the PK parameters of primary interest in at least 1 treatment period.

AUCinf for midazolam following single dose administration with and without PF-07321332/ritonavir was calculated by AUClast + (Clast/kel), where Clast was the predicted plasma concentration at the last quantifiable time point estimated from the log-linear regression analysis. Natural log-transformed AUCinf for Midazolam were analyzed using a mixed effect model with sequence, period and treatment as fixed effects and participant within sequence as a random effect. The ratios (PF-07321332/ritonavir + midazolam \[test\]/midazolam \[reference\] and 90% CIs) were expressed as percentages.

Outcome measures

Outcome measures
Measure
Midazolam 2 mg
n=10 Participants
Midazolam administered as a single dose on Day 1
PF-07321332 300 mg/Ritonavir 100 mg + Midazolam 2 mg
n=10 Participants
PF-07321332/ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Ritonavir 100 mg + Midazolam 2 mg
Participants administer Ritonavir orally every 12 hours for a total of 9 doses on Day1-5 and Midazolam orally as a single dose on Day 5, followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Area Under the Plasma Concentration-time Profile From Time 0 Extrapolated to Infinity Time (AUCinf) of Midazolam When Administered Alone and With PF-07321332/Ritonavir
26.13 ng*hr/mL
Geometric Coefficient of Variation 45
363.9 ng*hr/mL
Geometric Coefficient of Variation 13

PRIMARY outcome

Timeframe: Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam+PF-07321332/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose

Population: The PK parameter analysis population was defined as all participants randomized and treated who had at least 1 of the PK parameters of primary interest in at least 1 treatment period.

AUClast for midazolam following single dose administration with and without PF-07321332/ritonavir was calculated by Linear/Log trapezoidal method. Natural log-transformed AUClast for Midazolam were analyzed using a mixed effect model with sequence, period and treatment as fixed effects and participant within sequence as a random effect. The ratios (PF-07321332/ritonavir + midazolam \[test\]/midazolam \[reference\] and 90% CIs) were expressed as percentages.

Outcome measures

Outcome measures
Measure
Midazolam 2 mg
n=10 Participants
Midazolam administered as a single dose on Day 1
PF-07321332 300 mg/Ritonavir 100 mg + Midazolam 2 mg
n=10 Participants
PF-07321332/ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Ritonavir 100 mg + Midazolam 2 mg
Participants administer Ritonavir orally every 12 hours for a total of 9 doses on Day1-5 and Midazolam orally as a single dose on Day 5, followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Area Under the Plasma Concentration-time Profile From Time 0 to the Time of the Last Quantifiable Concentration (Clast) (AUClast) of Midazolam When Administered Alone and With PF-07321332/Ritonavir
25.02 ng*hr/mL
Geometric Coefficient of Variation 44
353.8 ng*hr/mL
Geometric Coefficient of Variation 13

SECONDARY outcome

Timeframe: Baseline up to Day 28

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

An adverse event was considered a TEAE if the event started during the effective duration of treatment. All events that start on or after the first dosing day and time/ start time, if collected, but before the last dose plus the lag time (28 days) were flagged as TEAEs. The algorithm did consider any events that started prior to the first dose date. Any events occurring following start of treatment or increasing in severity were counted as treatment emergent. Events that occur in a non-treatment period (for example, Washout or Follow-up) were counted as treatment emergent and attributed to the previous treatment taken.

Outcome measures

Outcome measures
Measure
Midazolam 2 mg
n=10 Participants
Midazolam administered as a single dose on Day 1
PF-07321332 300 mg/Ritonavir 100 mg + Midazolam 2 mg
n=11 Participants
PF-07321332/ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Ritonavir 100 mg + Midazolam 2 mg
n=11 Participants
Participants administer Ritonavir orally every 12 hours for a total of 9 doses on Day1-5 and Midazolam orally as a single dose on Day 5, followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Number of Participants With Treatment-emergent Adverse Events (TEAEs)
Participants with adverse events (All Causalities)
4 Participants
9 Participants
7 Participants
Number of Participants With Treatment-emergent Adverse Events (TEAEs)
Participants with adverse events (Treatment related)
4 Participants
9 Participants
7 Participants
Number of Participants With Treatment-emergent Adverse Events (TEAEs)
Participants with severe adverse events
0 Participants
0 Participants
0 Participants
Number of Participants With Treatment-emergent Adverse Events (TEAEs)
Participants with serious adverse events
0 Participants
0 Participants
0 Participants

SECONDARY outcome

Timeframe: Baseline up to Day 28

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

The haematological, clinical chemistry (serum) and urinalysis safety tests were assessed against the criteria specified in the sponsor reporting standards to determine if there were any clinically significant laboratory abnormalities. The assessment took into account whether each participant's baseline test result was within or outside the laboratory reference range for the particular laboratory parameter. Baseline was defined as the last planned predose measurement taken in each study period.

Outcome measures

Outcome measures
Measure
Midazolam 2 mg
n=10 Participants
Midazolam administered as a single dose on Day 1
PF-07321332 300 mg/Ritonavir 100 mg + Midazolam 2 mg
n=11 Participants
PF-07321332/ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Ritonavir 100 mg + Midazolam 2 mg
n=11 Participants
Participants administer Ritonavir orally every 12 hours for a total of 9 doses on Day1-5 and Midazolam orally as a single dose on Day 5, followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Number of Participants With Laboratory Abnormalities
HEMATOLOGY - Lymphocytes/Leukocytes (%) >1.2x ULN
0 Participants
0 Participants
1 Participants
Number of Participants With Laboratory Abnormalities
HEMATOLOGY - Neutrophils (10^3/mm^3) <0.8x LLN
0 Participants
0 Participants
1 Participants
Number of Participants With Laboratory Abnormalities
HEMATOLOGY - Neutrophils/Leukocytes (%) <0.8x LLN
0 Participants
1 Participants
1 Participants
Number of Participants With Laboratory Abnormalities
HEMATOLOGY - Eosinophils/Leukocytes (%) >1.2x ULN
0 Participants
1 Participants
1 Participants
Number of Participants With Laboratory Abnormalities
HEMATOLOGY - Monocytes/Leukocytes (%) >1.2x ULN
1 Participants
1 Participants
2 Participants
Number of Participants With Laboratory Abnormalities
HEMATOLOGY - Prothrombin Time (sec) >1.1x ULN
0 Participants
0 Participants
1 Participants
Number of Participants With Laboratory Abnormalities
CLINICAL CHEMISTRY - Thyrotropin (uIU/mL) <0.8x LLN
1 Participants
1 Participants
1 Participants
Number of Participants With Laboratory Abnormalities
CLINICAL CHEMISTRY - Fibrinogen (mg/dL) >1.25x Baseline
1 Participants
1 Participants
0 Participants
Number of Participants With Laboratory Abnormalities
URINALYSIS - URINE Hemoglobin (Scalar) ≥1
2 Participants
1 Participants
3 Participants

SECONDARY outcome

Timeframe: Baseline up to Day 28

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

Baseline was the last predose recording in each study period. Only post baseline values are included in this analysis

Outcome measures

Outcome measures
Measure
Midazolam 2 mg
n=10 Participants
Midazolam administered as a single dose on Day 1
PF-07321332 300 mg/Ritonavir 100 mg + Midazolam 2 mg
n=11 Participants
PF-07321332/ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Ritonavir 100 mg + Midazolam 2 mg
n=11 Participants
Participants administer Ritonavir orally every 12 hours for a total of 9 doses on Day1-5 and Midazolam orally as a single dose on Day 5, followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Number of Participants With Vital Signs Abnormalities
0 Participants
1 Participants
0 Participants

SECONDARY outcome

Timeframe: Baseline up to Day 28

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

Baseline and changes from baseline in PR, QT, QRS, heart rate and QTcF were summarized by treatment and time postdose. Baseline was defined as the average of the triplicate predose recordings in each study period. ECG endpoints and changes from baseline (QTcF, PR, QRS), over all measurements taken postdose, were also summarized descriptively by treatment using categories as defined in the Criteria for Safety Values of Potential Clinical Concern appendix of the protocol and for QTc values corresponding to ICH E14 thresholds, which are: QTcF (msec): 450\<value≤480; 480\<value≤500; \>500; QTcF (msec) increase from baseline: 30\<change≤60; change\>60

Outcome measures

Outcome measures
Measure
Midazolam 2 mg
n=10 Participants
Midazolam administered as a single dose on Day 1
PF-07321332 300 mg/Ritonavir 100 mg + Midazolam 2 mg
n=11 Participants
PF-07321332/ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Ritonavir 100 mg + Midazolam 2 mg
n=11 Participants
Participants administer Ritonavir orally every 12 hours for a total of 9 doses on Day1-5 and Midazolam orally as a single dose on Day 5, followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Number of Participants With Electrocardiogram (ECG) Abnormalities
PR INTERVAL, AGGREGATE (MSEC) - Value≥300
0 Participants
0 Participants
0 Participants
Number of Participants With Electrocardiogram (ECG) Abnormalities
QRS DURATION, AGGREGATE (MSEC) - Value≥140
0 Participants
0 Participants
0 Participants
Number of Participants With Electrocardiogram (ECG) Abnormalities
QRS DURATION, AGGREGATE (MSEC) - %Change≥50%
0 Participants
0 Participants
0 Participants
Number of Participants With Electrocardiogram (ECG) Abnormalities
QTCF INTERVAL, AGGREGATE (MSEC) - 450<Value≤480
0 Participants
0 Participants
0 Participants
Number of Participants With Electrocardiogram (ECG) Abnormalities
QTCF INTERVAL, AGGREGATE (MSEC) - Value>500
0 Participants
0 Participants
0 Participants
Number of Participants With Electrocardiogram (ECG) Abnormalities
QTCF INTERVAL, AGGREGATE (MSEC) - 30<Change≤60
0 Participants
0 Participants
0 Participants
Number of Participants With Electrocardiogram (ECG) Abnormalities
QTCF INTERVAL, AGGREGATE (MSEC) - Change>60
0 Participants
0 Participants
0 Participants
Number of Participants With Electrocardiogram (ECG) Abnormalities
PR INTERVAL, AGGREGATE (MSEC) - %Change≥25/50%
0 Participants
0 Participants
0 Participants
Number of Participants With Electrocardiogram (ECG) Abnormalities
QTCF INTERVAL, AGGREGATE (MSEC) - 480<Value≤500
0 Participants
0 Participants
0 Participants

SECONDARY outcome

Timeframe: Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose

Population: The PK parameter analysis population was defined as all participants randomized and treated who had at least 1 of the PK parameters of primary interest in at least 1 treatment period.

Cmax for midazolam following single dose administration with and without ritonavir was observed directly form data. Natural log-transformed Cmax for Midazolam were analyzed using a mixed effect model with sequence, period and treatment as fixed effects and participant within sequence as a random effect. The ratios (ritonavir + midazolam \[test\]/midazolam \[reference\] and 90% CIs) were expressed as percentages.

Outcome measures

Outcome measures
Measure
Midazolam 2 mg
n=10 Participants
Midazolam administered as a single dose on Day 1
PF-07321332 300 mg/Ritonavir 100 mg + Midazolam 2 mg
n=10 Participants
PF-07321332/ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Ritonavir 100 mg + Midazolam 2 mg
Participants administer Ritonavir orally every 12 hours for a total of 9 doses on Day1-5 and Midazolam orally as a single dose on Day 5, followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Cmax of Midazolam When Administered Alone and With Ritonavir
9.812 ng/mL
Geometric Coefficient of Variation 38
38.03 ng/mL
Geometric Coefficient of Variation 18

SECONDARY outcome

Timeframe: Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose

Population: The PK parameter analysis population was defined as all participants randomized and treated who had at least 1 of the PK parameters of primary interest in at least 1 treatment period.

AUCinf for midazolam following single dose administration with and without ritonavir was calculated by AUClast + (Clast/kel), where Clast was the predicted plasma concentration at the last quantifiable time point estimated from the log-linear regression analysis. Natural log-transformed AUCinf for Midazolam were analyzed using a mixed effect model with sequence, period and treatment as fixed effects and participant within sequence as a random effect. The ratios (ritonavir + midazolam \[test\]/midazolam \[reference\] and 90% CIs) were expressed as percentages.

Outcome measures

Outcome measures
Measure
Midazolam 2 mg
n=10 Participants
Midazolam administered as a single dose on Day 1
PF-07321332 300 mg/Ritonavir 100 mg + Midazolam 2 mg
n=10 Participants
PF-07321332/ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Ritonavir 100 mg + Midazolam 2 mg
Participants administer Ritonavir orally every 12 hours for a total of 9 doses on Day1-5 and Midazolam orally as a single dose on Day 5, followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
AUCinf of Midazolam When Administered Alone and With Ritonavir
26.13 ng*hr/mL
Geometric Coefficient of Variation 45
418.6 ng*hr/mL
Geometric Coefficient of Variation 15

SECONDARY outcome

Timeframe: Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam/ritonavir: Day 5 pre-dose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours post-dose

Population: The PK parameter analysis population was defined as all participants randomized and treated who had at least 1 of the PK parameters of primary interest in at least 1 treatment period.

AUClast for midazolam following single dose administration with and without ritonavir was calculated by Linear/Log trapezoidal method. Natural log-transformed AUClast for Midazolam were analyzed using a mixed effect model with sequence, period and treatment as fixed effects and participant within sequence as a random effect. The ratios (ritonavir + midazolam \[test\]/midazolam \[reference\] and 90% CIs) were expressed as percentages.

Outcome measures

Outcome measures
Measure
Midazolam 2 mg
n=10 Participants
Midazolam administered as a single dose on Day 1
PF-07321332 300 mg/Ritonavir 100 mg + Midazolam 2 mg
n=10 Participants
PF-07321332/ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Ritonavir 100 mg + Midazolam 2 mg
Participants administer Ritonavir orally every 12 hours for a total of 9 doses on Day1-5 and Midazolam orally as a single dose on Day 5, followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
AUClast of Midazolam When Administered Alone and With Ritonavir
25.02 ng*hr/mL
Geometric Coefficient of Variation 44
408.8 ng*hr/mL
Geometric Coefficient of Variation 15

SECONDARY outcome

Timeframe: Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam+PF-07321332/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose

Population: The PK parameter analysis population was defined as all participants randomized and treated who had at least 1 of the PK parameters of primary interest in at least 1 treatment period.

CL/F for midazolam following single dose administration with and without PF-07321332/ritonavir or ritonavir was calculated by Dose/AUCinf.

Outcome measures

Outcome measures
Measure
Midazolam 2 mg
n=10 Participants
Midazolam administered as a single dose on Day 1
PF-07321332 300 mg/Ritonavir 100 mg + Midazolam 2 mg
n=10 Participants
PF-07321332/ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Ritonavir 100 mg + Midazolam 2 mg
n=10 Participants
Participants administer Ritonavir orally every 12 hours for a total of 9 doses on Day1-5 and Midazolam orally as a single dose on Day 5, followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Apparent Clearance (CL/F) of Midazolam When Administered Alone, With PF-07321332/Ritonavir, and With Ritonavir
76.57 Litre/hour
Geometric Coefficient of Variation 45
5.500 Litre/hour
Geometric Coefficient of Variation 13
4.776 Litre/hour
Geometric Coefficient of Variation 15

SECONDARY outcome

Timeframe: Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam+PF-07321332/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose

Population: The PK parameter analysis population was defined as all participants randomized and treated who had at least 1 of the PK parameters of primary interest in at least 1 treatment period.

Vz/F for midazolam following single dose administration with and without PF-07321332/ritonavir or ritonavir was calculated by Dose/(AUCinf • kel).

Outcome measures

Outcome measures
Measure
Midazolam 2 mg
n=10 Participants
Midazolam administered as a single dose on Day 1
PF-07321332 300 mg/Ritonavir 100 mg + Midazolam 2 mg
n=10 Participants
PF-07321332/ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Ritonavir 100 mg + Midazolam 2 mg
n=10 Participants
Participants administer Ritonavir orally every 12 hours for a total of 9 doses on Day1-5 and Midazolam orally as a single dose on Day 5, followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Apparent Volume of Distribution (Vz/F) of Midazolam When Administered Alone, With PF-07321332/Ritonavir, and With Ritonavir
488.6 Litre
Geometric Coefficient of Variation 48
79.84 Litre
Geometric Coefficient of Variation 28
76.43 Litre
Geometric Coefficient of Variation 31

SECONDARY outcome

Timeframe: Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam+PF-07321332/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose

Population: The PK parameter analysis population was defined as all participants randomized and treated who had at least 1 of the PK parameters of primary interest in at least 1 treatment period.

Tmax for midazolam following single dose administration with and without PF-07321332/ritonavir or ritonavir was calculated by observed directly from data as time of first occurrence.

Outcome measures

Outcome measures
Measure
Midazolam 2 mg
n=10 Participants
Midazolam administered as a single dose on Day 1
PF-07321332 300 mg/Ritonavir 100 mg + Midazolam 2 mg
n=10 Participants
PF-07321332/ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Ritonavir 100 mg + Midazolam 2 mg
n=10 Participants
Participants administer Ritonavir orally every 12 hours for a total of 9 doses on Day1-5 and Midazolam orally as a single dose on Day 5, followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Time for Cmax (Tmax) of Midazolam When Administered Alone, With PF-07321332/Ritonavir, and With Ritonavir
1.00 Hour
Interval 0.5 to 1.1
1.00 Hour
Interval 0.5 to 1.05
1.02 Hour
Interval 0.5 to 3.17

SECONDARY outcome

Timeframe: Midazolam: Day 1 Predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36 hours postdose; Midazolam+PF-07321332/ritonavir: Day 5 predose, 0.5, 1, 2, 3, 4, 6, 8, 10, 12, 16, 24, 36, 48 and 72 hours postdose

Population: The PK parameter analysis population was defined as all participants randomized and treated who had at least 1 of the PK parameters of primary interest in at least 1 treatment period.

t½ for midazolam following single dose administration with and without PF-07321332/ritonavir or ritonavir was calculated by Loge(2)/kel, where kel was the terminal phase rate constant calculated by a linear regression of the log-linear concentration-time curve. Only those data points judged to describe the terminal log-linear.

Outcome measures

Outcome measures
Measure
Midazolam 2 mg
n=10 Participants
Midazolam administered as a single dose on Day 1
PF-07321332 300 mg/Ritonavir 100 mg + Midazolam 2 mg
n=10 Participants
PF-07321332/ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Ritonavir 100 mg + Midazolam 2 mg
n=10 Participants
Participants administer Ritonavir orally every 12 hours for a total of 9 doses on Day1-5 and Midazolam orally as a single dose on Day 5, followed by serial PK sampling and a 7-day washout (Duration: Day 1 to Day 12).
Terminal Half-life (t1/2) of Midazolam When Administered Alone, With PF-07321332/Ritonavir, and With Ritonavir
4.988 Hour
Standard Deviation 2.2058
10.47 Hour
Standard Deviation 2.9096
11.54 Hour
Standard Deviation 3.4741

Adverse Events

Midazolam 2 mg

Serious events: 0 serious events
Other events: 4 other events
Deaths: 0 deaths

PF-07321332 300 mg/Ritonavir 100 mg + Midazolam 2 mg

Serious events: 0 serious events
Other events: 9 other events
Deaths: 0 deaths

Ritonavir 100 mg + Midazolam 2 mg

Serious events: 0 serious events
Other events: 7 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure
Midazolam 2 mg
n=10 participants at risk
Midazolam administered as a single dose on Day 1
PF-07321332 300 mg/Ritonavir 100 mg + Midazolam 2 mg
n=11 participants at risk
PF-07321332/ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Ritonavir 100 mg + Midazolam 2 mg
n=11 participants at risk
Ritonavir: Administered orally every 12 hours for a total of 9 doses on Days 1-5 Midazolam: Administered orally as a single dose on Day 5
Cardiac disorders
Nodal rhythm
0.00%
0/10 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
Gastrointestinal disorders
Abdominal discomfort
0.00%
0/10 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
Gastrointestinal disorders
Abdominal pain
0.00%
0/10 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
Gastrointestinal disorders
Diarrhoea
0.00%
0/10 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
Gastrointestinal disorders
Dry mouth
0.00%
0/10 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
Gastrointestinal disorders
Dyspepsia
0.00%
0/10 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
Gastrointestinal disorders
Haematochezia
0.00%
0/10 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
General disorders
Chest discomfort
10.0%
1/10 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
General disorders
Fatigue
10.0%
1/10 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
General disorders
Vessel puncture site pain
0.00%
0/10 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
General disorders
Vessel puncture site reaction
10.0%
1/10 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
Infections and infestations
Folliculitis
0.00%
0/10 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
Musculoskeletal and connective tissue disorders
Back pain
0.00%
0/10 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
Nervous system disorders
Dysgeusia
0.00%
0/10 • Baseline up to Day 28
54.5%
6/11 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
Nervous system disorders
Headache
10.0%
1/10 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
Nervous system disorders
Somnolence
10.0%
1/10 • Baseline up to Day 28
27.3%
3/11 • Baseline up to Day 28
27.3%
3/11 • Baseline up to Day 28
Psychiatric disorders
Nightmare
10.0%
1/10 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
Reproductive system and breast disorders
Heavy menstrual bleeding
0.00%
0/10 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
Reproductive system and breast disorders
Vaginal haemorrhage
0.00%
0/10 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
Respiratory, thoracic and mediastinal disorders
Cough
10.0%
1/10 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
Respiratory, thoracic and mediastinal disorders
Dry throat
10.0%
1/10 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
Respiratory, thoracic and mediastinal disorders
Rhinorrhoea
0.00%
0/10 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
Skin and subcutaneous tissue disorders
Rash maculo-papular
0.00%
0/10 • Baseline up to Day 28
0.00%
0/11 • Baseline up to Day 28
9.1%
1/11 • Baseline up to Day 28

Additional Information

Pfizer ClinicalTrials.gov Call Center

Pfizer Inc.

Phone: 1-800-718-1021

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place