A Study to Learn How Different Forms of the Study Medicine Called PF-08049820 Are Absorbed and Eliminated in Healthy Adults

A PHASE 1, OPEN-LABEL, RANDOMIZED, 5-PERIOD, 6-SEQUENCE, CROSSOVER STUDY TO COMPARE THE SINGLE-DOSE PHARMACOKINETICS OF ONE IMMEDIATE RELEASE AND TWO MODIFIED-RELEASE FORMULATIONS OF PF-08049820 ADMINISTERED ORALLY UNDER FASTED AND FED CONDITIONS (PART A), AND A FIXED SEQUENCE STUDY TO ASSESS THE EFFECT OF RABEPRAZOLE ON THE PHARMACOKINETICS OF PF-08049820 (PART B), IN HEALTHY ADULTS

The purpose of this study is to learn how different forms of the study medicine called PF-08049820 are absorbed and eliminated in healthy adults. The study will assess whether the study medicine is absorbed differently when taken with or without food. It will also assess absorption when the study medicine is taken with another medicine called rabeprazole. Rabeprazole is an FDA approved medicine that reduces stomach acid.

The study has two parts. In Part A, participants will take three forms of study medicine, one after the other. They will take each form either with or without food for a total of five doses. Each dose will be separated by a few days. Participants will stay in the clinic for about two weeks. They will receive a telephone follow-up call about a month after the last dose.

In Part B, participants will take three forms of study medicine. They will take each one with or without food, and with or without another medicine called rabeprazole. This means they will take a total of six doses of study medicine. Each dose will be separated by a few days. Participants will stay at the clinic for about three weeks, and about a month after their last dose. They will get a follow-up phone call. Part B may or may not be conducted depending on the results from Part A.

The study is seeking participants who:

1. Are males or females,
2. Are at least 18 years of age,
3. Have a body mass index (BMI) 16 to 32 kilograms per meter squared (kg/m2). Have a total body weight of more than 50 kilograms (kg) (110 pounds).

Study Overview

• Status: Not yet recruiting
• Conditions: Healthy; Healthy Adults
• Intervention / Treatment: Drug: PF-08049820; Drug: Rabeprazole

• Study Type: Interventional
• Enrollment (Estimated): 24
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Pfizer CT.gov Call Center; Phone Number: 1-800-718-1021; Email: ClinicalTrials.gov_Inquiries@pfizer.com

Study Locations

• United States
  • Connecticut
    • New Haven, Connecticut, United States, 06511
      • Pfizer Clinical Research Unit - New Haven

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Healthy males and females.
2. At least 18 years of age
3. Body mass index (BMI) of 16-32 kg/m2; and a total body weight >50kg (110 lb.).

Exclusion Criteria:

1. Evidence or history of clinically significant medical conditions.
2. History of human immunodeficiency virus (HIV) infection, hepatitis B, or hepatitis C; positive testing for HIV, hepatitis B or hepatitis C.
3. History of alcohol abuse or binge drinking and/or any other illicit drug use or dependence within 6 months of Screening.
4. Participation in studies of other investigational products (drug or vaccine) at any time during their participation in this study.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

7

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Sequence 1 (Part A); 3 different formulations of PF-08049820 administered orally under fasted or fed conditions.	Drug: PF-08049820; Administered orally
Experimental: Sequence 2 (Part A); 3 different formulations of PF-08049820 administered orally under fasted or fed conditions.	Drug: PF-08049820; Administered orally
Experimental: Sequence 3 (Part A); 3 different formulations of PF-08049820 administered orally under fasted or fed conditions.	Drug: PF-08049820; Administered orally
Experimental: Sequence 4 (Part A); 3 different formulations of PF-08049820 administered orally under fasted or fed conditions.	Drug: PF-08049820; Administered orally
Experimental: Sequence 5 (Part A); 3 different formulations of PF-08049820 administered orally under fasted or fed conditions.	Drug: PF-08049820; Administered orally
Experimental: Sequence 6 (Part A); 3 different formulations of PF-08049820 administered orally under fasted or fed conditions.	Drug: PF-08049820; Administered orally
Experimental: Sequence 7 (Optional Part B); 3 different formulations of PF-08049820 administered orally with or without rabeprazole under fasted or fed conditions.	Drug: PF-08049820; Administered orally; Drug: Rabeprazole; Administered orally

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Area under the concentration-time curve from time zero to the time of the last quantifiable concentration (AUClast)	Part A: Evaluate the relative bioavailability of different formulations of PF-08049820. Optional Part B: Estimate the effect of rabeprazole on the PK of different formulations of PF-08049820.	Baseline up to Day 16 for Part A and up to Day 24 for optional Part B
Area under the curve from time zero to extrapolated infinite time (AUCinf) if data permit	Part A: Evaluate the relative bioavailability of 3 different formulations of PF-08049820. Optional Part B: Estimate the effect of rabeprazole on the PK of different formulations of PF-08049820.	Baseline up to Day 16 for Part A and up to Day 24 for optional Part B
Maximum observed plasma concentration (Cmax)	Part A: Evaluate the relative bioavailability of 3 different formulations of PF-08049820. Optional Part B: Estimate the effect of rabeprazole on the PK of different formulations of PF-08049820.	Baseline up to Day 16 for Part A and up to Day 24 for optional Part B

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With Treatment Emergent Adverse Events (TEAEs)	Part A and optional Part B	Baseline up to Day 48 for Part A and up to Day 56 for optional Part B
Number of Participants With Serious Adverse Events (SAEs)	Part A and optional Part B	Baseline up to Day 48 for Part A and up to Day 56 for optional Part B
Number of Participants With Clinically Significant Change From Baseline in Laboratory Abnormalities	Part A and optional Part B	Baseline up to Day 16 for Part A and up to Day 24 for optional Part B
Number of Participants With Clinically Significant Change From Baseline in Vital Signs	Part A and optional Part B	Baseline up to Day 16 for Part A and up to Day 24 for optional Part B
Number of Participants With Clinically Significant Change From Baseline in Electrocardiogram (ECG) Findings	Part A and optional Part B	Baseline up to Day 16 for Part A and up to Day 24 for optional Part B
Area under the concentration-time curve from time zero to the time of the last quantifiable concentration (AUClast)	Part A only: Evaluate the food effect on the PK of different formulations of PF-08049820.	Baseline up to Day 16 for Part A
Area under the curve from time zero to extrapolated infinite time (AUCinf) if data permit	Part A only: Evaluate the food effect on the PK of different formulations of PF-08049820.	Baseline up to Day 16 for Part A
Maximum observed plasma concentration (Cmax)	Part A only: Evaluate the food effect on the PK of different formulations of PF-08049820.	Baseline up to Day 16 for Part A

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 (Estimated): May 12, 2026
• Primary Completion (Estimated): September 3, 2026
• Study Completion (Estimated): September 25, 2026

Study Registration Dates

• First Submitted: May 12, 2026
• First Submitted That Met QC Criteria: May 12, 2026
• First Posted (Actual): May 20, 2026

Study Record Updates

• Last Update Posted (Actual): May 20, 2026
• Last Update Submitted That Met QC Criteria: May 12, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: 2-Pyridinylmethylsulfinylbenzimidazoles; Sulfoxides; Sulfur Compounds; Organic Chemicals; Pyridines; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Benzimidazoles; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Rabeprazole
• Other Study ID Numbers: C6231008

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.: No