Acne VulgarisPhase 1NCT06671834
A Study to Learn About the Study Medicine Called PF-07905428 in Healthy Participants and Participants With Acne Vulgaris
A Phase 1 study testing PF-07905428 in people with Acne Vulgaris, run by Pfizer at 1 site in Canada.
Trial summary
The purpose of this clinical trial is to learn about the safety and effects of the study medicine (called PF-07905428) for the potential treatment of acne vulgaris. This study is seeking participants who: Are male or female between the ages of 18 and 40 Are generally healthy Are diagnosed with moderate to severe acne… Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Acne Vulgaris
- What is being tested?
- PF-07905428
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 52 participants
- Where
- 1 siteCanada
- Study dates
- 22 Nov 2024to 4 Dec 2025
- Phase
- Phase 1
- Are there results?
- None posted in the registry
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 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Participants who are overtly healthy as determined by medical evaluation.
- Only for participants who are enrolling with acne vulgaris: diagnosis of acne vulgaris for 3 months or greater
- For participants enrolling in Cohort 1-3 with acne vulgaris (optional): mild to moderate facial acne vulgaris
- For participants enrolling in Cohort 4 with acne vulgaris: moderate to severe facial acne vulgaris
Who cannot join
- Participants with very severe acne
- Participants with autoinflammatory syndromes
- Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurological, or allergic disease
- History of human immunodeficiency virus (HIV) infection, hepatitis B, or hepatitis C.
- Participants with clinically significant laboratory abnormalities
Trial locations and contacts
1 site in 1 country.
About this study
Official title: A PHASE 1, RANDOMIZED, DOUBLE-BLIND, SPONSOR-OPEN, PLACEBO-CONTROLLED, DOSE ESCALATION STUDY TO EVALUATE THE SAFETY, TOLERABILITY, PHARMACOKINETICS, AND PHARMACODYNAMICS OF MULTIPLE-DOSE TOPICAL ADMINISTRATION OF PF-07905428 IN HEALTHY PARTICIPANTS AND PARTICIPANTS WITH ACNE VULGARIS, AND ADDITIONALLY CLINICAL EFFECT IN PARTICIPANTS WITH MODERATE TO SEVERE ACNE VULGARIS AGED 18 TO 40 YEARS OLD
The purpose of this clinical trial is to learn about the safety and effects of the study medicine (called PF-07905428) for the potential treatment of acne vulgaris.
This study is seeking participants who:
Read more
- Are male or female between the ages of 18 and 40
- Are generally healthy
- Are diagnosed with moderate to severe acne vulgaris (Cohort 4 only)
The study medicine will be applied every day on the participant's face and/or back for 14 days (Cohorts 1 and 2) or for 28 days (Cohort 3 and 4).
The investigators will compare the experiences of people receiving the study medicine to those of the people who do not. This will help the investigators determine if the study medicine is safe and effective.
Participants will take part in this study for approximately 2 months. During this time, they will have 17 study visits (Cohorts 1 and 2) or 31 study visits (Cohorts 3 and 4) at the study clinic. The study team will also call participants once at the end of the study over the phone.
- Conditions
- Acne Vulgaris
- Being tested
- PF-07905428, Placebo
- Medical subject headings
- Acne Vulgaris
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PF-07905428Drug
Topical solution of PF-07905428 0.08% or PF-07905428 0.24%
PlaceboDrug
Topical solution of placebo
| Study group | Role | What they receive |
|---|---|---|
| PF-07905428 Low Strength | Experimental | Participants may receive 0.08% PF-07905428 QD. Area of application will be increased as the study proceeds from one cohort to the next. Receives: Drug: PF-07905428 |
| PF-07905428 High Strength | Experimental | Participants may receive 0.24% PF-07905428 QD. Area of application will be increased as the study proceeds from one cohort to the next. Receives: Drug: PF-07905428 |
| Placebo | Placebo comparator | All participants will receive Placebo QD. Area of application will be increased as the study proceeds from one cohort to the next. Receives: Drug: Placebo |
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) and Serious Adverse Events (SAEs)
An adverse event (AE) was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. TEAEs were events between first dose of study drug and up to 37 days after last dose that were absent before treatment or that worsened relative to pretreatment state. An SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. TEAEs included SAEs and all non-SAEs that occurred during the study.
Measured: Through study completion, approximately 2 months
Number of Participants With Clinical Laboratory Abnormalities
Evaluation of participants with clinically meaningful changes from baseline in laboratory test results
Measured: Through study completion, approximately 2 months
Number of Participants With Abnormalities in Vital Signs
Any untoward vital sign findings that are identified during the active collection period and meet the definition of an AE or SAE.
Measured: Through study completion, approximately 2 months
Number of Participants With Clinically Significant Changes From Baseline in 12-Lead Electrocardiogram (ECG) Parameters
12-lead ECG were performed after the participant had rested quietly for at least 10 minutes in a supine position. ECG parameters included RR interval, PR interval, QRS complex, QT interval, corrected QT (QTc) interval, Bazett's correction QT (QTcB) interval, Heart Rate and Fridericia's correction (QTcF) interval. Clinical significance of 12-Lead ECG was judged by investigator.
Measured: Through study completion, approximately 2 months
Secondary outcomes (8)
Maximum plasma concentration (Cmax) of PF-07905428
Measured: Day 14 (Cohorts 1, 2, and 4) Day 28 (Cohorts 3 and 4)
Time to maximum plasma concentration (Tmax) of PF-07905428
Measured: Day 14 (Cohorts 1, 2, and 4) Day 28 (Cohorts 3 and 4)
Area Under the Serum Concentration-Time Curve Over the Dosing Interval (AUCtau) of PF-07905428
Area under the plasma concentration-time curve from time 0 to the end of the dosing interval (AUCtau)
Measured: Day 14 (Cohorts 1, 2, and 4) Day 28 (Cohorts 3 and 4)
Terminal serum elimination half life (t1/2) of PF-07905428
Measured: Day 14 (Cohorts 1, 2, and 4) Day 28 (Cohorts 3 and 4)
Absolute change in total acne lesion counts
To compare the clinical effect of PF-07905428 versus placebo on absolute change from baseline in total lesion count (TLC) in participants with moderate to severe acne vulgaris.
Measured: Baseline to Week 4
Absolute change from baseline in inflammatory lesion counts (ILC)
To compare the clinical effect of PF-07905428 versus placebo on absolute change from baseline in inflammatory lesion counts (ILC) in participants with moderate to severe acne vulgaris.
Measured: Baseline to Week 4
Absolute change in non-inflammatory lesion counts (nILC)
To compare the clinical effect of PF-07905428 versus placebo on absolute change from baseline in non-inflammatory lesion counts (nILC) in participants with moderate to severe acne vulgaris.
Measured: Baseline to Week 4
Percentage of Participants who achieve Investigator global assessment (IGA) of 0 or 1
Percentage of participants who achieve IGA score of "clear" or "almost clear" on the face (modified IGA of 0 or 1) with 2-points or greater improvement at Week 4 compared to placebo.
Measured: Baseline to Week 4
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Nov 2024
- Study start22 Nov 2024
- Primary completion4 Dec 2025
- Study completion4 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Acne VulgarisStudies 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
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 52 participants (actual)
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
- NCT06671834
- Sponsor's protocol ID
- C5441001
- Other IDs
- NCT06671834
- Status last verified
- Dec 2025
- First submitted
- 18 Oct 2024
- Last updated
- 30 Dec 2025
- 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 30 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A PHASE 1, RANDOMIZED, DOUBLE-BLIND, SPONSOR-OPEN, PLACEBO-CONTROLLED, DOSE ESCALATION STUDY TO EVALUATE THE SAFETY, TOLERABILITY, PHARMACOKINETICS, AND PHARMACODYNAMICS OF MULTIPLE-DOSE TOPICAL ADMINISTRATION OF PF-07905428 IN HEALTHY PARTICIPANTS AND PARTICIPANTS WITH ACNE VULGARIS, AND ADDITIONALLY CLINICAL EFFECT IN PARTICIPANTS WITH MODERATE TO SEVERE ACNE VULGARIS AGED 18 TO 40 YEARS OLD
- ClinicalTrials.gov ID
- NCT06671834
- Acronym / sponsor ID
- C5441001
- Conditions
- Acne Vulgaris
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 52 participants (actual)
- Lead sponsor
- PfizerIndustry (pharma, biotech, devices)
- Study start
- 22 Nov 2024 (actual)
- Primary completion
- 4 Dec 2025 (actual)
- Study completion
- 4 Dec 2025 (actual)
- First posted
- 4 Nov 2024 (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 clinical trial is to learn about the safety and effects of the study medicine (called PF-07905428) for the potential treatment of acne vulgaris.
This study is seeking participants who:
- Are male or female between the ages of 18 and 40
- Are generally healthy
- Are diagnosed with moderate to severe acne vulgaris (Cohort 4 only)
The study medicine will be applied every day on the participant's face and/or back for 14 days (Cohorts 1 and 2) or for 28 days (Cohort 3 and 4).
The investigators will compare the experiences of people receiving the study medicine to those of the people who do not. This will help the investigators determine if the study medicine is safe and effective.
Participants will take part in this study for approximately 2 months. During this time, they will have 17 study visits (Cohorts 1 and 2) or 31 study visits (Cohorts 3 and 4) at the study clinic. The study team will also call participants once at the end of the study over the phone.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, investigator)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| PF-07905428 Low Strength | Experimental | Drug: PF-07905428Participants may receive 0.08% PF-07905428 QD. Area of application will be increased as the study proceeds from one cohort to the next. |
| PF-07905428 High Strength | Experimental | Drug: PF-07905428Participants may receive 0.24% PF-07905428 QD. Area of application will be increased as the study proceeds from one cohort to the next. |
| Placebo | Placebo comparator | Drug: PlaceboAll participants will receive Placebo QD. Area of application will be increased as the study proceeds from one cohort to the next. |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Participants who are overtly healthy as determined by medical evaluation.
- Only for participants who are enrolling with acne vulgaris: diagnosis of acne vulgaris for 3 months or greater
- For participants enrolling in Cohort 1-3 with acne vulgaris (optional): mild to moderate facial acne vulgaris
- For participants enrolling in Cohort 4 with acne vulgaris: moderate to severe facial acne vulgaris
Key exclusion criteria (5 listed)
- Participants with very severe acne
- Participants with autoinflammatory syndromes
- Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurological, or allergic disease
- History of human immunodeficiency virus (HIV) infection, hepatitis B, or hepatitis C.
- Participants with clinically significant laboratory abnormalities
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-07905428Topical solution of PF-07905428 0.08% or PF-07905428 0.24% | Drug | PF-07905428 High Strength, PF-07905428 Low Strength |
| PlaceboTopical solution of placebo | Drug | Placebo |
Primary outcome
Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs)
Time frame: Through study completion, approximately 2 months
An adverse event (AE) was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. TEAEs were events between first dose of study drug and up to 37 days after last dose that were absent before treatment or that worsened relative to pretreatment state. An SAE was an AE resulting in any of the following outcomes or deemed significant for any other reason: death; initial or prolonged inpatient hospitalization; life-threatening experience (immediate risk of dying); persistent or significant disability/incapacity; congenital anomaly. TEAEs included SAEs and all non-SAEs that occurred during the study.
Number of Participants With Clinical Laboratory Abnormalities
Time frame: Through study completion, approximately 2 months
Evaluation of participants with clinically meaningful changes from baseline in laboratory test results
Number of Participants With Abnormalities in Vital Signs
Time frame: Through study completion, approximately 2 months
Any untoward vital sign findings that are identified during the active collection period and meet the definition of an AE or SAE.
Number of Participants With Clinically Significant Changes From Baseline in 12-Lead Electrocardiogram (ECG) Parameters
Time frame: Through study completion, approximately 2 months
12-lead ECG were performed after the participant had rested quietly for at least 10 minutes in a supine position. ECG parameters included RR interval, PR interval, QRS complex, QT interval, corrected QT (QTc) interval, Bazett's correction QT (QTcB) interval, Heart Rate and Fridericia's correction (QTcF) interval. Clinical significance of 12-Lead ECG was judged by investigator.
8 secondary outcomes
Maximum plasma concentration (Cmax) of PF-07905428
Time frame: Day 14 (Cohorts 1, 2, and 4) Day 28 (Cohorts 3 and 4)
Time to maximum plasma concentration (Tmax) of PF-07905428
Time frame: Day 14 (Cohorts 1, 2, and 4) Day 28 (Cohorts 3 and 4)
Area Under the Serum Concentration-Time Curve Over the Dosing Interval (AUCtau) of PF-07905428
Time frame: Day 14 (Cohorts 1, 2, and 4) Day 28 (Cohorts 3 and 4)
Terminal serum elimination half life (t1/2) of PF-07905428
Time frame: Day 14 (Cohorts 1, 2, and 4) Day 28 (Cohorts 3 and 4)
Absolute change in total acne lesion counts
Time frame: Baseline to Week 4
Absolute change from baseline in inflammatory lesion counts (ILC)
Time frame: Baseline to Week 4
Absolute change in non-inflammatory lesion counts (nILC)
Time frame: Baseline to Week 4
Percentage of Participants who achieve Investigator global assessment (IGA) of 0 or 1
Time frame: Baseline to Week 4
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Dec 2025.
- 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. This study is not recruiting at the moment.
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-07905428 in people with Acne Vulgaris, run by Pfizer at 1 site in Canada.
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 4 inclusion and 5 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: finished, as of the sponsor's last update on 30 Dec 2025. 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 Canada. 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?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants With Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events (SAEs) (time frame: Through study completion, approximately 2 months). The study lists 4 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 30 Dec 2025.