Healthy Volunteer StudyPhase 1NCT07660731
A Study to Learn How Different Amounts of the Study Medicine Called PF-08103402 Are Tolerated and Act in the Body in Healthy Adults or Adults With Mild To-moderate Asthma
A Phase 1 study testing PF-08103402 and Midazolam in people with Healthy Volunteer Study and Healthy Adults, run by Pfizer at 1 site in United States.
Trial summary
The purpose of this study is to learn about the safety of a new study medicine called PF-08103402 in healthy adults (do not have disease) and or in adults with mild-to-moderate asthma. This is the first time the study medicine is being given to people. Read more about this study
- Who is it for?
- Ages 18 to 65 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Volunteer Study, Healthy Adults, Healthy Participants
- What is being tested?
- PF-08103402 and Midazolam
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 133 participants
- Where
- 1 siteUnited States
- Study dates
- 17 Jun 2026to 30 Mar 2027
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Are males or females who can no longer have children,
- Are 18 to 65 years old,
- Have a body mass index (BMI) of 16 to 32 kilograms per meter squared and a total body weight of more than 50 kilograms (110 pounds).
- For Part A (Optional group or cohort 3: Japanese participants only):
- A total body weight of more than 45 kg (100 pounds).
- Have 4 biological Japanese grandparents who were born in Japan.
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- For Part E only:
- Adults with a documented doctor's-diagnosis history of asthma for at least 12 months before entering the study.
- Have a body mass index (BMI) of 16 to 35 kilograms per meter squared and a total body weight of more than 50 kilograms (110 pounds).
Who cannot join
- Evidence or history of clinically significant medical conditions.
- History of human immunodeficiency virus (HIV) infection, hepatitis B, or hepatitis C; positive testing for HIV, hepatitis B surface antigen (HBsAg), or hepatitis C antibody (HCVAb).
- History of alcohol abuse or binge drinking and/or any other illicit drug use or dependence within 6 months of Screening.
- Participation in studies of other investigational products (drug or vaccine) at any time during their participation in this study.
- Any history of parasitic infection requiring treatment within 28 days prior to screening.
- Positive tuberculosis infection test result.
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- Part C only: Evidence or history of conditions interfering with the ability to taste.
- Part D only: History of irregular bowel movements.
- Part E only: Evidence of lung disease(s) other than asthma.
- Part E only: Asthma exacerbation within 3 months prior to screening.
- Part F only: History of acute narrow-angle glaucoma, untreated open-angle glaucoma, sleep apnea, respiratory insufficiency, myasthenia gravis or adverse reaction to midazolam or other benzodiazepines.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Pfizer Clinical Research Unit - New Haven
New Haven, Connecticut, 06511
About this study
Official title: A PHASE 1 STUDY TO EVALUATE SAFETY, TOLERABILITY, PHARMACOKINETICS, PHARMACODYNAMICS, FOOD EFFECT, METABOLISM & EXCRETION, AND DRUG-DRUG INTERACTION POTENTIAL OF PF-08103402 IN HEALTHY ADULTS AND/OR ADULTS WITH MILD TO MODERATE ASTHMA
The purpose of this study is to learn about the safety of a new study medicine called PF-08103402 in healthy adults (do not have disease) and or in adults with mild-to-moderate asthma. This is the first time the study medicine is being given to people.
For Parts A, B, C, D and F, the study is seeking participants who:
Read more
- Are healthy (do not have disease) males or females who can no longer have children,
- Are 18 to 65 years old,
- Have a body mass index (BMI) of 16 to 32 kilograms per meter squared and a body weight of more than 50 kilograms (110 pounds). Body mass index is a way to measure body fat by using a person's height and weight
For Part A (optional group or cohort 3: Japanese participants only):
- A body weight of more than 45 kilograms (100 pounds).
- Have 4 biological Japanese grandparents who were born in Japan.
For Part E only:
- Adults with a documented history of asthma (confirmed by a doctor) for at least 12 months before entering the study.
- Have a body mass index (BMI) of 16 to 35 kilograms per meter squared and a total body weight of more than 50 kilograms (110 pounds).
The study has six parts: Part A, Part B, Part C, Part D, Part E and Part F. The study medicine will be taken as a suspension or tablet by mouth 1 time a day (except in Parts B and E where it will be taken 1 time a day for 14 days) at the study clinic. The study will help understand:
- how the body processes the study medicine in healthy participants (Parts A and B),
- how much of the study medicine gets into the bloodstream and if food affects the amount of study medicine in the blood in healthy participants (Part C),
- how the study medicine is broken down and leaves the body in healthy participants (Optional Part D),
- how the study medicine is processed in adults with mild-to-moderate asthma (Optional Part E),
- if taking the study medicine together with another medicine affects how each medicine is processed by the body in healthy participants (Optional Part F).
Participants will take part in the study for about 10 weeks (Parts A and F), 12 weeks (Part B), 9 weeks (Parts C and D), and 16 weeks (Part E).
During this time, they will have 2 study visits at the study clinic and up to 28 overnight stays (Part A), 18 overnight stays (Parts B and E), 10 overnight stays (Part C), 11 overnight stays (Part D), and 16 overnight stays (Part F). The study team will also call participants 1 time over the phone at the end of the study to assess how they are doing.
Study measurements will be taken by body examination, monitoring side effects, blood and urine tests, heart tests (ECG), vital signs (blood pressure, pulse and respiratory rate), questionnaires (Parts C and E), stool samples (Part D only), and breathing tests (Part E only).
- Conditions
- Healthy Volunteer Study, Healthy Adults, Healthy Participants, Asthma
- Being tested
- PF-08103402, Placebo, Midazolam
- Keywords
- Human, Randomized, Metabolism, Excretion, Drug-Drug Interaction, Food effect
- Medical subject headings
- Asthma
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PF-08103402Drug
Oral suspension (Parts A to F); Tablets (Parts C and F only)
PlaceboDrug
Oral suspension (Parts A, B and E).
MidazolamDrug
Oral syrup
| Study group | Role | What they receive |
|---|---|---|
| Part A: Cohorts 1, 2 and Optional Cohort 3 | Placebo comparator | PF-08103402 as suspensions (Cohorts 1 and 2)/tablets (Optional Cohort 3) or matching placebo as a single oral dose on Day 1 of each period Receives: Drug: PF-08103402; Drug: Placebo |
| Part B: Cohorts 4, 5, 6, 7, and Optional Cohort 8 | Placebo comparator | PF-08103402 as tablets or matching placebo given once daily oral doses from Day 1 through Day 14. Receives: Drug: PF-08103402; Drug: Placebo |
| Part C: Cohort 9 | Other | PF-08103402 as a single oral dose as tablets on Day 1 of each period Receives: Drug: PF-08103402 |
| Part D: Cohort 10 (Optional) | Other | PF-08103402 as a single oral dose as tablets on Day 1. Receives: Drug: PF-08103402 |
| Part E: Cohorts 11 (Optional) and 12 (Optional) | Placebo comparator | PF-08103402 as tablets or corresponding placebo as oral doses from Day 1 through Day 14. Receives: Drug: PF-08103402; Drug: Placebo |
| Part F: Cohort 13 (Optional) | Other | Period 1: Single oral dose of midazolam on Day 1. Period 2: Once daily oral dose of PF-08103402 as tablets from Day 1 through Day 14 and a single oral dose of midazolam on Day 14 after the administration of PF-08103402. Receives: Drug: PF-08103402; Drug: Midazolam |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants with Treatment Emergent Adverse Events (TEAEs)
Part A: Cohorts 1, 2 and Cohort 3 (optional). Part B: Cohorts 4, 5, 6, and 7 and Cohort 8 (optional). Part E: Cohorts 11 (optional) and 12 (optional)
Measured: Parts A: Up to Day 36; Part B and E: Up to Day 50
Number of Participants with Serious Adverse Events (SAEs)
Part A: Cohorts 1, 2 and Cohort 3 (optional). Part B: Cohorts 4, 5, 6, and 7 and Cohort 8 (optional). Part E: Cohorts 11 (optional) and 12 (optional)
Measured: Parts A: Up to Day 36; Part B and E: Up to Day 50
Number of Participants With Clinically Significant Change From Baseline in Laboratory Abnormalities
Part A: Cohorts 1, 2 and Cohort 3 (optional). Part B: Cohorts 4, 5, 6, and 7 and Cohort 8 (optional). Part E: Cohorts 11 (optional) and 12 (optional)
Measured: Parts A: Change From Baseline to Day 7; Part B and E: Change From Baseline to Day 17
Number of Participants With Clinically Significant Change From Baseline in Vital Signs
Part A: Cohorts 1, 2 and Cohort 3 (optional). Part B: Cohorts 4, 5, 6, and 7 and Cohort 8 (optional). Part E: Cohorts 11 (optional) and 12 (optional).
Measured: Parts A: Change From Baseline to Day 7; Part B and E: Change From Baseline to Day 17
Number of Participants With Clinically Significant Change From Baseline in Electrocardiogram (ECG) Findings
Part A: Cohorts 1, 2 and Cohort 3 (optional). Part B: Cohorts 4, 5, 6, and 7 and Cohort 8 (optional). Part E: Cohorts 11 (optional) and 12 (optional).
Measured: Parts A: Change From Baseline to Day 7; Part B and E: Change From Baseline to Day 17
Area under the curve from time zero to extrapolated infinite time (AUCinf) if data permit, otherwise (AUClast) in the fasted state
Part C: Cohort 9
Measured: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1
Maximum observed plasma concentration (Cmax) in the fasted state
Part C: Cohort 9
Measured: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1
Total recovery of drug-related material in urine and feces separately, and both routes combined, expressed as a percent of total dose administered
Part D: Cohort 10 (optional)
Measured: Pre-dose (Hour 0) and at 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 hours post-dose (Day 2)
Maximum observed plasma concentration (Cmax)
Part F: Cohort 13 (optional)
Measured: Pre-dose (Hour 0) and at 0.5, 1, 2, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 hours post-dose (Day 2)
Area under the curve from time zero to extrapolated infinite time (AUCinf) if data permit, otherwise AUClast
Part F: Cohort 13 (optional)
Measured: Pre-dose (Hour 0) and at 0.5, 1, 2, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 hours post-dose (Day 2)
Secondary outcomes (34)
Area under the concentration-time curve from time zero to the time of the last quantifiable concentration (AUClast)
Part A: Cohorts 1, 2 and Cohort 3 (optional).
Measured: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 and 36 hours post-dose (Day 2)
Maximum observed plasma concentration (Cmax)
Part A: Cohorts 1, 2 and Cohort 3 (optional).
Measured: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 and 36 hours post-dose (Day 2)
Time of Maximum observed plasma concentration (Tmax)
Part A: Cohorts 1, 2 and Cohort 3 (optional).
Measured: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 and 36 hours post-dose (Day 2)
Area under the curve from time zero to extrapolated infinite time (AUCinf) if data permit
Part A: Cohorts 1, 2 and Cohort 3 (optional).
Measured: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 and 36 hours post-dose (Day 2)
Half-life (t½) if data permit
Part A: Cohorts 1, 2 and Cohort 3 (optional)
Measured: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 and 36 hours post-dose (Day 2)
Area under the curve over 1 dosing interval (AUCtau)
Part B: Cohorts 4, 5, 6, and 7 and Cohort 8 (optional).
Measured: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 and 24 hours post-dose on Day 1, Day 7 and Day 14
Maximum observed plasma concentration (Cmax)
Part B: Cohorts 4, 5, 6, and 7 and Cohort 8 (optional).
Measured: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 and 24 hours post-dose on Day 1, Day 7 and Day 14
Time of Maximum observed plasma concentration (Tmax)
Part B: Cohorts 4, 5, 6, and 7 and Cohort 8 (optional).
Measured: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 and 24 hours post-dose on Day 1, Day 7 and Day 14
Half-life (t½) if data permit
Part B: Cohorts 4, 5, 6, and 7 and Cohort 8 (optional).
Measured: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 and 24 hours post-dose on Day 1, Day 7 and Day 14
Number of Participants with Treatment Emergent Adverse Events (TEAEs)
Part C: Cohort 9
Measured: Up to Day 36
Number of Participants With Serious Adverse Events (SAEs)
Part C: Cohort 9
Measured: Up to Day 36
Number of Participants With Clinically Significant Change From Baseline in Laboratory Abnormalities
Part C: Cohort 9
Measured: Change From Baseline to Day 4
Number of Participants With Clinically Significant Change From Baseline in Vital Signs
Part C: Cohort 9
Measured: Change From Baseline to Day 4
Number of Participants With Clinically Significant Change From Baseline in Electrocardiogram (ECG) Findings
Part C: Cohort 9
Measured: Change From Baseline to Day 4
Number of Participants with Treatment Emergent Adverse Events (TEAEs)
Part D: Cohort 10 (optional)
Measured: Up to Day 36
Number of Participants With Serious Adverse Events (SAEs)
Part D: Cohort 10 (optional)
Measured: Up to Day 36
Number of Participants With Clinically Significant Change From Baseline in Laboratory Abnormalities
Part D: Cohort 10 (optional)
Measured: Change From Baseline to Day 11
Number of Participants With Clinically Significant Change From Baseline in Vital Signs
Part D: Cohort 10 (optional)
Measured: Change From Baseline to Day 11
Number of Participants With Clinically Significant Change From Baseline in Electrocardiogram (ECG) Findings
Part D: Cohort 10 (optional)
Measured: Change From Baseline to Day 11
Area under the curve from time zero to extrapolated infinite time (AUCinf) if data permit, otherwise AUClast
Part D: Cohort 10 (optional)
Measured: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1, 24 hours post-dose (Day 2), 48 hours post-dose (Day 3), 72 hours post-dose (Day 4), 96 hours post-dose (Day 5), 120 hours post-dose (Day 6), 144 hours post-dose (Day 7)
Maximum observed plasma concentration (Cmax)
Part D: Cohort 10 (optional)
Measured: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1, 24 hours post-dose (Day 2), 48 hours post-dose (Day 3), 72 hours post-dose (Day 4), 96 hours post-dose (Day 5), 120 hours post-dose (Day 6), 144 hours post-dose (Day 7).
Change From Baseline (CFB) in Fractional concentration of exhaled Nitric Oxide (FeNO) at Day 14
Part E: Cohorts 11 (optional) and 12 (optional)
Measured: Pre-dose (Hour 0) and at 72 hours post-dose (Day 4), 144 hours post-dose (Day 7), 264 hours post-dose (Day 12), 312 hours post-dose (Day 14) and 384 hours post-dose (Day 17)
Area under the curve over 1 dosing interval (AUCtau)
Part E: Cohorts 11 (optional) and 12 (optional)
Measured: Pre-dose (Hour 0), 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose (Day 1); 24 hours post-dose (Day 2); 144 hours post-dose (Day 7); 312 hours post-dose (Day 14); 336 hours post-dose (Day 15); 360 hours post-dose (Day 16); 384 hours post-dose (Day 17)
Maximum observed plasma concentration (Cmax)
Part E: Cohorts 11 (optional) and 12 (optional)
Measured: Pre-dose (Hour 0), 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose (Day 1); 24 hours post-dose (Day 2); 144 hours post-dose (Day 7); 312 hours post-dose (Day 14); 336 hours post-dose (Day 15); 360 hours post-dose (Day 16); 384 hours post-dose (Day 17)
Time of Maximum observed plasma concentration (Tmax)
Part E: Cohorts 11 (optional) and 12 (optional)
Measured: Pre-dose (Hour 0), 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose (Day 1); 24 hours post-dose (Day 2); 144 hours post-dose (Day 7); 312 hours post-dose (Day 14); 336 hours post-dose (Day 15); 360 hours post-dose (Day 16); 384 hours post-dose (Day 17)
Half-life (t½) if data permit
Part E: Cohorts 11 (optional) and 12 (optional)
Measured: Pre-dose (Hour 0), 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose (Day 1); 24 hours post-dose (Day 2); 144 hours post-dose (Day 7); 312 hours post-dose (Day 14); 336 hours post-dose (Day 15); 360 hours post-dose (Day 16); 384 hours post-dose (Day 17)
Number of Participants With Treatment Emergent Adverse Events (TEAEs)
Part F: Cohort 13 (optional)
Measured: Up to Day 51
Number of Participants With Serious Adverse Events (SAEs)
Part F: Cohort 13 (optional)
Measured: Up to Day 51
Number of Participants With Clinically Significant Change From Baseline in Vital Signs
Part F: Cohort 13 (optional)
Measured: Change From Baseline to Day 16
Number of Participants With Clinically Significant Change From Baseline in Electrocardiogram (ECG) Findings
Part F: Cohort 13 (optional)
Measured: Change From Baseline to Day 16
Area under the curve over 1 dosing interval (AUCtau)
Part F: Cohort 13 (optional)
Measured: Pre-dose (Hour 0) and at 0.5, 1, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 hours post-dose (Day 2)
Maximum observed plasma concentration (Cmax)
Part F: Cohort 13 (optional)
Measured: Pre-dose (Hour 0) and at 0.5, 1, 2, 3, 4, 6, 8, 12 and 24 hours post-dose on Day 1 (Period 1 ) and on Day 1 and Day 14 (Period 2)
Time of Maximum observed plasma concentration (Tmax)
Part F: Cohort 13 (optional)
Measured: Pre-dose (Hour 0) and at 0.5, 1, 2, 3, 4, 6, 8, 12 and 24 hours post-dose on Day 1 (Period 1 ) and on Day 1 and Day 14 (Period 2)
Half-life (t½) if data permit
Part F: Cohort 13 (optional)
Measured: Pre-dose (Hour 0) and at 0.5, 1, 2, 3, 4, 6, 8, 12 and 24 hours post-dose on Day 1 (Period 1 ) and on Day 1 and Day 14 (Period 2)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Jun 2026
- Study start17 Jun 2026
- Primary completion30 Mar 2027 (estimated)
- Study completion30 Mar 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Healthy Volunteer StudyStudies of the same condition, open and under way.
- More trials run by PfizerThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Sequential
- Model description
- Sequential design (Part A), Parallel design (Part B), Crossover design (Parts C \& F), Single period (Parts D \& E)
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 133 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Pfizer
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Pfizer CT.gov Call Center, Study director, Pfizer
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07660731
- Sponsor's protocol ID
- C6611001
- Other IDs
- 2026-526260-21-00
- Status last verified
- Oct 2026
- First submitted
- 16 Jun 2026
- Last updated
- 13 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical\_trials/trial\_data\_and\_results/data\_requests.
Study at a glance
From the registry record, last updated by the sponsor on 13 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A PHASE 1 STUDY TO EVALUATE SAFETY, TOLERABILITY, PHARMACOKINETICS, PHARMACODYNAMICS, FOOD EFFECT, METABOLISM & EXCRETION, AND DRUG-DRUG INTERACTION POTENTIAL OF PF-08103402 IN HEALTHY ADULTS AND/OR ADULTS WITH MILD TO MODERATE ASTHMA
- ClinicalTrials.gov ID
- NCT07660731
- Acronym / sponsor ID
- C6611001
- Conditions
- Healthy Volunteer Study, Healthy Adults, Healthy Participants, Asthma
- Keywords
- Human, Randomized, Metabolism, Excretion, Drug-Drug Interaction, Food effect
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 133 participants (estimated)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 17 Jun 2026 (actual)
- Primary completion
- 30 Mar 2027 (estimated)
- Study completion
- 30 Mar 2027 (estimated)
- First posted
- 22 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to learn about the safety of a new study medicine called PF-08103402 in healthy adults (do not have disease) and or in adults with mild-to-moderate asthma. This is the first time the study medicine is being given to people.
For Parts A, B, C, D and F, the study is seeking participants who:
- Are healthy (do not have disease) males or females who can no longer have children,
- Are 18 to 65 years old,
- Have a body mass index (BMI) of 16 to 32 kilograms per meter squared and a body weight of more than 50 kilograms (110 pounds). Body mass index is a way to measure body fat by using a person's height and weight
For Part A (optional group or cohort 3: Japanese participants only):
- A body weight of more than 45 kilograms (100 pounds).
- Have 4 biological Japanese grandparents who were born in Japan.
For Part E only:
- Adults with a documented history of asthma (confirmed by a doctor) for at least 12 months before entering the study.
- Have a body mass index (BMI) of 16 to 35 kilograms per meter squared and a total body weight of more than 50 kilograms (110 pounds).
The study has six parts: Part A, Part B, Part C, Part D, Part E and Part F. The study medicine will be taken as a suspension or tablet by mouth 1 time a day (except in Parts B and E where it will be taken 1 time a day for 14 days) at the study clinic. The study will help understand:
- how the body processes the study medicine in healthy participants (Parts A and B),
- how much of the study medicine gets into the bloodstream and if food affects the amount of study medicine in the blood in healthy participants (Part C),
- how the study medicine is broken down and leaves the body in healthy participants (Optional Part D),
- how the study medicine is processed in adults with mild-to-moderate asthma (Optional Part E),
- if taking the study medicine together with another medicine affects how each medicine is processed by the body in healthy participants (Optional Part F).
Participants will take part in the study for about 10 weeks (Parts A and F), 12 weeks (Part B), 9 weeks (Parts C and D), and 16 weeks (Part E).
During this time, they will have 2 study visits at the study clinic and up to 28 overnight stays (Part A), 18 overnight stays (Parts B and E), 10 overnight stays (Part C), 11 overnight stays (Part D), and 16 overnight stays (Part F). The study team will also call participants 1 time over the phone at the end of the study to assess how they are doing.
Study measurements will be taken by body examination, monitoring side effects, blood and urine tests, heart tests (ECG), vital signs (blood pressure, pulse and respiratory rate), questionnaires (Parts C and E), stool samples (Part D only), and breathing tests (Part E only).
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Sequential
- Masking
- Double blind (participant, investigator)
- Number of arms
- 6
- Model description
- Sequential design (Part A), Parallel design (Part B), Crossover design (Parts C \& F), Single period (Parts D \& E)
| Arm | Type | Receives |
|---|---|---|
| Part A: Cohorts 1, 2 and Optional Cohort 3 | Placebo comparator | Drug: PF-08103402, Drug: PlaceboPF-08103402 as suspensions (Cohorts 1 and 2)/tablets (Optional Cohort 3) or matching placebo as a single oral dose on Day 1 of each period |
| Part B: Cohorts 4, 5, 6, 7, and Optional Cohort 8 | Placebo comparator | Drug: PF-08103402, Drug: PlaceboPF-08103402 as tablets or matching placebo given once daily oral doses from Day 1 through Day 14. |
| Part C: Cohort 9 | Other | Drug: PF-08103402PF-08103402 as a single oral dose as tablets on Day 1 of each period |
| Part D: Cohort 10 (Optional) | Other | Drug: PF-08103402PF-08103402 as a single oral dose as tablets on Day 1. |
| Part E: Cohorts 11 (Optional) and 12 (Optional) | Placebo comparator | Drug: PF-08103402, Drug: PlaceboPF-08103402 as tablets or corresponding placebo as oral doses from Day 1 through Day 14. |
| Part F: Cohort 13 (Optional) | Other | Drug: PF-08103402, Drug: MidazolamPeriod 1: Single oral dose of midazolam on Day 1. Period 2: Once daily oral dose of PF-08103402 as tablets from Day 1 through Day 14 and a single oral dose of midazolam on Day 14 after the administration of PF-08103402. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (9 listed)
- Are males or females who can no longer have children,
- Are 18 to 65 years old,
- Have a body mass index (BMI) of 16 to 32 kilograms per meter squared and a total body weight of more than 50 kilograms (110 pounds).
- A total body weight of more than 45 kg (100 pounds).
- Have 4 biological Japanese grandparents who were born in Japan.
Key exclusion criteria (11 listed)
- Evidence or history of clinically significant medical conditions.
- History of human immunodeficiency virus (HIV) infection, hepatitis B, or hepatitis C; positive testing for HIV, hepatitis B surface antigen (HBsAg), or hepatitis C antibody (HCVAb).
- History of alcohol abuse or binge drinking and/or any other illicit drug use or dependence within 6 months of Screening.
- Participation in studies of other investigational products (drug or vaccine) at any time during their participation in this study.
- Any history of parasitic infection requiring treatment within 28 days prior to screening.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| PF-08103402Oral suspension (Parts A to F); Tablets (Parts C and F only) | Drug | Part A: Cohorts 1, 2 and Optional Cohort 3, Part B: Cohorts 4, 5, 6, 7, and Optional Cohort 8, Part C: Cohort 9, Part D: Cohort 10 (Optional), Part E: Cohorts 11 (Optional) and 12 (Optional), Part F: Cohort 13 (Optional) |
| PlaceboOral suspension (Parts A, B and E). | Drug | Part A: Cohorts 1, 2 and Optional Cohort 3, Part B: Cohorts 4, 5, 6, 7, and Optional Cohort 8, Part E: Cohorts 11 (Optional) and 12 (Optional) |
| MidazolamOral syrup | Drug | Part F: Cohort 13 (Optional) |
Primary outcome
Number of Participants with Treatment Emergent Adverse Events (TEAEs)
Time frame: Parts A: Up to Day 36; Part B and E: Up to Day 50
Part A: Cohorts 1, 2 and Cohort 3 (optional). Part B: Cohorts 4, 5, 6, and 7 and Cohort 8 (optional). Part E: Cohorts 11 (optional) and 12 (optional)
Number of Participants with Serious Adverse Events (SAEs)
Time frame: Parts A: Up to Day 36; Part B and E: Up to Day 50
Part A: Cohorts 1, 2 and Cohort 3 (optional). Part B: Cohorts 4, 5, 6, and 7 and Cohort 8 (optional). Part E: Cohorts 11 (optional) and 12 (optional)
Number of Participants With Clinically Significant Change From Baseline in Laboratory Abnormalities
Time frame: Parts A: Change From Baseline to Day 7; Part B and E: Change From Baseline to Day 17
Part A: Cohorts 1, 2 and Cohort 3 (optional). Part B: Cohorts 4, 5, 6, and 7 and Cohort 8 (optional). Part E: Cohorts 11 (optional) and 12 (optional)
Number of Participants With Clinically Significant Change From Baseline in Vital Signs
Time frame: Parts A: Change From Baseline to Day 7; Part B and E: Change From Baseline to Day 17
Part A: Cohorts 1, 2 and Cohort 3 (optional). Part B: Cohorts 4, 5, 6, and 7 and Cohort 8 (optional). Part E: Cohorts 11 (optional) and 12 (optional).
Number of Participants With Clinically Significant Change From Baseline in Electrocardiogram (ECG) Findings
Time frame: Parts A: Change From Baseline to Day 7; Part B and E: Change From Baseline to Day 17
Part A: Cohorts 1, 2 and Cohort 3 (optional). Part B: Cohorts 4, 5, 6, and 7 and Cohort 8 (optional). Part E: Cohorts 11 (optional) and 12 (optional).
Area under the curve from time zero to extrapolated infinite time (AUCinf) if data permit, otherwise (AUClast) in the fasted state
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1
Part C: Cohort 9
Maximum observed plasma concentration (Cmax) in the fasted state
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1
Part C: Cohort 9
Total recovery of drug-related material in urine and feces separately, and both routes combined, expressed as a percent of total dose administered
Time frame: Pre-dose (Hour 0) and at 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 hours post-dose (Day 2)
Part D: Cohort 10 (optional)
Maximum observed plasma concentration (Cmax)
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 2, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 hours post-dose (Day 2)
Part F: Cohort 13 (optional)
Area under the curve from time zero to extrapolated infinite time (AUCinf) if data permit, otherwise AUClast
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 2, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 hours post-dose (Day 2)
Part F: Cohort 13 (optional)
34 secondary outcomes
Area under the concentration-time curve from time zero to the time of the last quantifiable concentration (AUClast)
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 and 36 hours post-dose (Day 2)
Maximum observed plasma concentration (Cmax)
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 and 36 hours post-dose (Day 2)
Time of Maximum observed plasma concentration (Tmax)
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 and 36 hours post-dose (Day 2)
Area under the curve from time zero to extrapolated infinite time (AUCinf) if data permit
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 and 36 hours post-dose (Day 2)
Half-life (t½) if data permit
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 and 36 hours post-dose (Day 2)
Area under the curve over 1 dosing interval (AUCtau)
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 and 24 hours post-dose on Day 1, Day 7 and Day 14
Maximum observed plasma concentration (Cmax)
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 and 24 hours post-dose on Day 1, Day 7 and Day 14
Time of Maximum observed plasma concentration (Tmax)
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 and 24 hours post-dose on Day 1, Day 7 and Day 14
Half-life (t½) if data permit
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 and 24 hours post-dose on Day 1, Day 7 and Day 14
Number of Participants with Treatment Emergent Adverse Events (TEAEs)
Time frame: Up to Day 36
Number of Participants With Serious Adverse Events (SAEs)
Time frame: Up to Day 36
Number of Participants With Clinically Significant Change From Baseline in Laboratory Abnormalities
Time frame: Change From Baseline to Day 4
Number of Participants With Clinically Significant Change From Baseline in Vital Signs
Time frame: Change From Baseline to Day 4
Number of Participants With Clinically Significant Change From Baseline in Electrocardiogram (ECG) Findings
Time frame: Change From Baseline to Day 4
Number of Participants with Treatment Emergent Adverse Events (TEAEs)
Time frame: Up to Day 36
Number of Participants With Serious Adverse Events (SAEs)
Time frame: Up to Day 36
Number of Participants With Clinically Significant Change From Baseline in Laboratory Abnormalities
Time frame: Change From Baseline to Day 11
Number of Participants With Clinically Significant Change From Baseline in Vital Signs
Time frame: Change From Baseline to Day 11
Number of Participants With Clinically Significant Change From Baseline in Electrocardiogram (ECG) Findings
Time frame: Change From Baseline to Day 11
Area under the curve from time zero to extrapolated infinite time (AUCinf) if data permit, otherwise AUClast
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1, 24 hours post-dose (Day 2), 48 hours post-dose (Day 3), 72 hours post-dose (Day 4), 96 hours post-dose (Day 5), 120 hours post-dose (Day 6), 144 hours post-dose (Day 7)
Maximum observed plasma concentration (Cmax)
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1, 24 hours post-dose (Day 2), 48 hours post-dose (Day 3), 72 hours post-dose (Day 4), 96 hours post-dose (Day 5), 120 hours post-dose (Day 6), 144 hours post-dose (Day 7).
Change From Baseline (CFB) in Fractional concentration of exhaled Nitric Oxide (FeNO) at Day 14
Time frame: Pre-dose (Hour 0) and at 72 hours post-dose (Day 4), 144 hours post-dose (Day 7), 264 hours post-dose (Day 12), 312 hours post-dose (Day 14) and 384 hours post-dose (Day 17)
Area under the curve over 1 dosing interval (AUCtau)
Time frame: Pre-dose (Hour 0), 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose (Day 1); 24 hours post-dose (Day 2); 144 hours post-dose (Day 7); 312 hours post-dose (Day 14); 336 hours post-dose (Day 15); 360 hours post-dose (Day 16); 384 hours post-dose (Day 17)
Maximum observed plasma concentration (Cmax)
Time frame: Pre-dose (Hour 0), 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose (Day 1); 24 hours post-dose (Day 2); 144 hours post-dose (Day 7); 312 hours post-dose (Day 14); 336 hours post-dose (Day 15); 360 hours post-dose (Day 16); 384 hours post-dose (Day 17)
Time of Maximum observed plasma concentration (Tmax)
Time frame: Pre-dose (Hour 0), 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose (Day 1); 24 hours post-dose (Day 2); 144 hours post-dose (Day 7); 312 hours post-dose (Day 14); 336 hours post-dose (Day 15); 360 hours post-dose (Day 16); 384 hours post-dose (Day 17)
Half-life (t½) if data permit
Time frame: Pre-dose (Hour 0), 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12 hours post-dose (Day 1); 24 hours post-dose (Day 2); 144 hours post-dose (Day 7); 312 hours post-dose (Day 14); 336 hours post-dose (Day 15); 360 hours post-dose (Day 16); 384 hours post-dose (Day 17)
Number of Participants With Treatment Emergent Adverse Events (TEAEs)
Time frame: Up to Day 51
Number of Participants With Serious Adverse Events (SAEs)
Time frame: Up to Day 51
Number of Participants With Clinically Significant Change From Baseline in Vital Signs
Time frame: Change From Baseline to Day 16
Number of Participants With Clinically Significant Change From Baseline in Electrocardiogram (ECG) Findings
Time frame: Change From Baseline to Day 16
Area under the curve over 1 dosing interval (AUCtau)
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 2, 3, 4, 6, 8, 12 hours post-dose on Day 1 and at 24 hours post-dose (Day 2)
Maximum observed plasma concentration (Cmax)
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 2, 3, 4, 6, 8, 12 and 24 hours post-dose on Day 1 (Period 1 ) and on Day 1 and Day 14 (Period 2)
Time of Maximum observed plasma concentration (Tmax)
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 2, 3, 4, 6, 8, 12 and 24 hours post-dose on Day 1 (Period 1 ) and on Day 1 and Day 14 (Period 2)
Half-life (t½) if data permit
Time frame: Pre-dose (Hour 0) and at 0.5, 1, 2, 3, 4, 6, 8, 12 and 24 hours post-dose on Day 1 (Period 1 ) and on Day 1 and Day 14 (Period 2)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Oct 2026.
- To obtain contact information for a study center near you, click here.Link provided by the sponsor.
- Individual participant dataSharing planned: No. Pfizer will provide access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), Clinical Study Report (CSR)) upon request from qualified researchers, and subject to certain criteria, conditions, and exceptions. Further details on Pfizer's data sharing criteria and process for requesting access can be found at: https://www.pfizer.com/science/clinical_trials/trial_data_and_results/data_requests.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Pfizer CT.gov Call Center study director
Pfizer
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing PF-08103402 and Midazolam in people with Healthy Volunteer Study and Healthy Adults, run by Pfizer at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 9 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 13 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Pfizer CT.gov Call Center (1-800-718-1021, ClinicalTrials.gov_Inquiries@pfizer.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants with Treatment Emergent Adverse Events (TEAEs) (time frame: Parts A: Up to Day 36; Part B and E: Up to Day 50). The study lists 10 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Oct 2026.