A Study to Learn About the Study Medicine Called PF-07905428 in Healthy Participants and Participants With Acne Vulgaris

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:

• 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 Overview

• Status: Completed
• Conditions: Acne Vulgaris
• Intervention / Treatment: Drug: PF-07905428; Drug: Placebo

• Study Type: Interventional
• Enrollment (Actual): 52
• Phase: Phase 1

Contacts and Locations

Study Locations

• Canada
  • Quebec
    • Montreal, Quebec, Canada, H2X 2V1
      • Innovaderm Research Inc.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• 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

Exclusion Criteria:

• 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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: PF-07905428 Low Strength; Participants may receive 0.08% PF-07905428 QD. Area of application will be increased as the study proceeds from one cohort to the next.	Drug: PF-07905428; Topical solution of PF-07905428 0.08% or PF-07905428 0.24%
Experimental: PF-07905428 High Strength; Participants may receive 0.24% PF-07905428 QD. Area of application will be increased as the study proceeds from one cohort to the next.	Drug: PF-07905428; Topical solution of PF-07905428 0.08% or PF-07905428 0.24%
Placebo Comparator: Placebo; All participants will receive Placebo QD. Area of application will be increased as the study proceeds from one cohort to the next.	Drug: Placebo; Topical solution of placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	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	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.	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.	Through study completion, approximately 2 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximum plasma concentration (Cmax) of PF-07905428		Day 14 (Cohorts 1, 2, and 4) Day 28 (Cohorts 3 and 4)
Time to maximum plasma concentration (Tmax) of PF-07905428		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)	Day 14 (Cohorts 1, 2, and 4) Day 28 (Cohorts 3 and 4)
Terminal serum elimination half life (t1/2) of PF-07905428		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.	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.	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.	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.	Baseline to Week 4

Collaborators and Investigators

• Sponsor: Pfizer
• Investigators: Study Director: Pfizer CT.gov Call Center, Pfizer

Publications and helpful links

Helpful Links

• To obtain contact information for a study center near you, click here.

Study record dates

Study Major Dates

• Study Start (Actual): November 22, 2024
• Primary Completion (Actual): December 4, 2025
• Study Completion (Actual): December 4, 2025

Study Registration Dates

• First Submitted: October 18, 2024
• First Submitted That Met QC Criteria: October 31, 2024
• First Posted (Actual): November 4, 2024

Study Record Updates

• Last Update Posted (Actual): December 30, 2025
• Last Update Submitted That Met QC Criteria: December 29, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Skin Diseases; Acneiform Eruptions; Sebaceous Gland Diseases; Skin and Connective Tissue Diseases; Acne Vulgaris; Substandard Drugs; Pharmaceutical Preparations; Counterfeit Drugs
• Other Study ID Numbers: C5441001; NCT06671834 (Registry Identifier: ClinicalTrials.gov)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: 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.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: Yes