A Study to Learn How Different Amounts of the Study Medicine Called PF-07941944 Are Tolerated in the Body of Healthy Adults.

A Multipart Phase 1 Randomized, Double-Blind, Sponsor-Open, Placebo-Controlled Study With Single and Multiple Dose Escalation to Evaluate the Safety, Tolerability, and Pharmacokinetics of PF-07941944 in Healthy Adult Participants

The purpose of this clinical trial is to learn about the safety and tolerability of the study medicine (called PF-07941944) in healthy participants.

This study is seeking participants who:

• Are male or female between the ages of 18 and 60
• Are generally healthy

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 well tolerated.

Participants enrolled in Part 1 will take part in this study for approximately 4 months. Participants enrolled in Part 2 or Part 3 will take part in this study for approximately 2.5 months. Study visits will take place 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: Healthy Participants
• Intervention / Treatment: Drug: Placebo; Drug: PF-07941944; Drug: Midazolam

• Study Type: Interventional
• Enrollment (Actual): 25
• Phase: Phase 1

Contacts and Locations

Study Locations

• Belgium
  • Bruxelles-capitale, Région DE
    • Brussels, Bruxelles-capitale, Région DE, Belgium, B-1070
      • Pfizer Clinical Research Unit - Brussels

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
• Body mass index (BMI) of 17.5 to 30.5 kg/m2
• For inclusion of Japanese participants: participants who have 4 Japanese biologic grandparents who were born in Japan.

Exclusion Criteria:

• Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurological, or allergic disease
• Any medical or psychiatric condition including recent (within the past year) or active suicidal ideation/behavior or laboratory abnormality or other conditions that may increase the risk of study participation
• Use of prescription or nonprescription drugs and dietary and herbal supplements within 28 days or 5 half-lives (whichever is longer) prior to the first dose of study intervention.
• Previous administration with an investigational product (drug or vaccine) within 30 days (or as determined by the local requirement) or 5 half-lives preceding the first dose of study intervention used in this study (whichever is longer).
• History of alcohol abuse or repeated binge drinking and/or any other illicit drug use or dependence within 6 months of Screening.
• Part 3 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. History of hypersensitivity reaction to midazolam, or any of the formulation components.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Part 1; Single ascending dose of PF-07941944 or placebo in healthy adult participants	Drug: Placebo; Oral formulation; Drug: PF-07941944; Oral formulation
Experimental: Part 2; Multiple doses of PF-07941944 or placebo in healthy adult participants	Drug: Placebo; Oral formulation; Drug: PF-07941944; Oral formulation
Experimental: Part 3 (Optional); Period 1, single dose of Midazolam. Period 2, multiple doses of PF-07941944 + Midazolam	Drug: PF-07941944; Oral formulation; Drug: Midazolam; Oral formulation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With Treatment Emergent Treatment-Related Adverse Events (AEs)	Part 1 and Part 2	Baseline through end of study, approximately 16 weeks
Number of Participants With Clinically Significant Change From Baseline in Laboratory Abnormalities	Part 1 and Part 2	Baseline through end of study, approximately 16 weeks
Number of Participants With Clinically Significant Change From Baseline in Vital Signs	Part 1 and Part 2	Baseline through end of study, approximately 16 weeks
Number of Participants With Change From Baseline in Electrocardiogram (ECG) Findings	Part 1 and Part 2	Baseline through end of study, approximately 16 weeks
Maximum Observed Plasma Concentration (Cmax)	Part 3	Baseline through end of study, approximately 16 weeks
Area Under the Curve From Time Zero to Extrapolated Infinite Time (AUCinf)	Part 3 - if data permit	Baseline through end of study, approximately 16 weeks
Area Under the Curve From Time Zero to Last Quantifiable Concentration (AUClast)	Part 3 - If AUCinf not collected	Baseline through end of study, approximately 16 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cmax	Part 1 and Part 2	Baseline through end of study, approximately 16 weeks
Time to Reach Maximum Observed Plasma Concentration (Tmax)	Part 1 and Part 2	Baseline through end of study, approximately 16 weeks
AUClast	Part 1 - if data permit	Baseline through end of study, approximately 16 weeks
AUCinf	Part 1 - if data permit	Baseline through end of study, approximately 16 weeks
Plasma Decay Half-Life (t1/2)	Part 1 and Part 2 - if data permit	Baseline through end of study, approximately 16 weeks
Area Under the Curve from Time Zero to end of dosing interval (AUCtau)	Part 2	Baseline through end of study, approximately 16 weeks
Number of Participants With Treatment Emergent Treatment-Related AEs	Part 3 - Optional	Baseline through end of study, approximately 16 weeks
Number of Participants With Clinically Significant Change From Baseline in Laboratory Abnormalities	Part 3 - Optional	Baseline through end of study, approximately 16 weeks
Number of Participants With Clinically Significant Change From Baseline in Vital Signs	Part 3 - Optional	Baseline through end of study, approximately 16 weeks
Number of Participants With Change From Baseline in ECG Findings	Part 3 - Optional	Baseline through end of study, approximately 16 weeks

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): December 3, 2024
• Primary Completion (Actual): June 19, 2025
• Study Completion (Actual): June 19, 2025

Study Registration Dates

• First Submitted: December 5, 2024
• First Submitted That Met QC Criteria: April 1, 2025
• First Posted (Actual): April 9, 2025

Study Record Updates

• Last Update Posted (Actual): July 17, 2025
• Last Update Submitted That Met QC Criteria: July 16, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: Respiratory syncytial virus (RSV)
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Anesthetics; Central Nervous System Depressants; Neurotransmitter Agents; Adjuvants, Anesthesia; Hypnotics and Sedatives; Anti-Anxiety Agents; Tranquilizing Agents; Psychotropic Drugs; Anesthetics, Intravenous; Anesthetics, General; GABA Modulators; GABA Agents; Midazolam
• Other Study ID Numbers: C5961001; 2024-515421-28-00 (Registry Identifier: CTIS (EU))

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