A Study to Learn if a Medicine Called Itraconazole Changes How the Body Processes the Study Medicine PF-08642534 in Healthy Adults.

A PHASE 1, OPEN-LABEL, FIXED-SEQUENCE STUDY TO EVALUATE THE EFFECT OF ITRACONAZOLE ON THE PHARMACOKINETICS OF SINGLE ORAL DOSES OF PF-08642534 IN HEALTHY ADULT PARTICIPANTS

The purpose of this study is to learn if a medicine called itraconazole changes how the body processes the study medicine (PF-08642534) in healthy adults.

This study is seeking healthy participants (men or women) who:

• are aged 18 to 65 years of age
• are confirmed to be healthy by their medical history and medical tests
• have body mass index (BMI) of 16 to 30 kilograms per meter squared
• have a total body weight of more than 50 kilograms.

Participants will receive single doses of the study medicine (PF-08642534) with and without itraconazole.

The total planned time of participation is about 12 weeks. The study consists of:

• a screening period of up to 28 days before taking study drug
• about 4 weeks of staying in the study clinic
• a follow-up contact that will occur 28 to 35 days after taking itraconazole the last time.

Study Overview

• Status: Not yet recruiting
• Conditions: Healthy Participant
• Intervention / Treatment: Drug: PF-08642534; Drug: Itraconazole

• Study Type: Interventional
• Enrollment (Estimated): 14
• 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
      • New Haven Clinical Research Unit

Participation Criteria

Eligibility Criteria

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

Description

Inclusion criteria:

• Generally healthy as determined by medical evaluation including medical history, physical examination, laboratory tests, blood pressure, pulse rate and standard 12-lead electrocardiogram (ECG).
• Body Mass Index (BMI) of 16-30 kilograms per meter squared, inclusive, and a total body weight greater than 50 kilograms (110 pounds).

Exclusion criteria:

• Evidence or history of clinically significant disease
• Specified abnormalities in safety assessments at Screening

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Period 1--PF-08642534; Participants will receive a single dose of PF-08642534	Drug: PF-08642534; Participants will receive a single dose of PF-08642534
Experimental: Period 2--itraconazole plus PF-08642534; Participants will receive single doses of PF-08642534) in presence of itraconazole.	Drug: PF-08642534; Participants will receive a single dose of PF-08642534; Drug: Itraconazole; Participants will receive itraconazole once daily for 13 days (Day 12 to Day 24)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
PF-08642534 Area Under the Curve From Time Zero to Last Quantifiable Concentration (AUClast)	0 to 240 hours post-dose

Secondary Outcome Measures

Outcome Measure	Time Frame
Incidence of treatment-emergent Adverse Events	Baseline up to approximately 8 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 (Estimated): May 5, 2026
• Primary Completion (Estimated): June 26, 2026
• Study Completion (Estimated): July 23, 2026

Study Registration Dates

• First Submitted: May 4, 2026
• First Submitted That Met QC Criteria: May 4, 2026
• First Posted (Actual): May 8, 2026

Study Record Updates

• Last Update Posted (Actual): May 8, 2026
• Last Update Submitted That Met QC Criteria: May 4, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Azoles; Triazoles; Piperazines; Itraconazole
• Other Study ID Numbers: C6601002

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