A Study to Learn If the Study Medicine Called Carbamazepine Changes How the Body Processes the Other Study Medicine Ibuzatrelvir in Healthy Adults

A PHASE 1, OPEN-LABEL, FIXED SEQUENCE STUDY TO ESTIMATE THE EFFECT OF CARBAMAZEPINE ON THE PHARMACOKINETICS OF IBUZATRELVIR IN HEALTHY ADULT PARTICIPANTS

The purpose of this study is to estimate the effect of carbamazepine, a strong CYP3A4 inducer, on the pharmacokinetics (PK) of ibuzatrelvir in healthy participants.

This study is seeking participants who:

• are male or female that are not of childbearing potential of 18 years of age or older
• are examined to be healthy

The study will consist of two treatments: (1) a single oral dose of ibuzatrelvir 600 mg alone in Period 1 and (2) carbamazepine q12h (BID) titrated from 100 mg to 300 mg over 15 days with a single ibuzatrelvir 600 mg dose coadministered on day 15 in Period 2. All treatments will be taken by mouth.

All participants will remain in the study clinic for 18 days for safety review, laboratory collections, and to collect samples for PK.

All participants selected in the study will be required to go through a screening period up to 28 days. A screening period is the time during which a few participants are examined to see whether they are fit for the study. During this period, the participant's medical history and past and current medications will be reviewed. A series of tests will also be performed to see if they are good to be selected for the study. If the participant meets all required criteria and are interested in continuing, the participant will be brought into the study clinic to stay overnight for 18 days. About 28 to 35 days after discharge following the final treatment, the participant will be contacted for a follow up visit either in person or by telephone. This is to check up on how the participant is doing and to conclude the study.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Drug: ibuzatrelvir; Drug: carbamazepine ER

• Study Type: Interventional
• Enrollment (Actual): 12
• Phase: Phase 1

Contacts and Locations

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:

Participants are eligible to be included in the study only if all of the following criteria apply:

-Male participants and female participants who are not of childbearing potential who are overtly healthy as determined by medical evaluation including medical history, physical examination, laboratory tests, blood pressure, pulse rate and standard 12 lead ECG

Exclusion Criteria:

Participants are excluded from the study if any of the following criteria apply:

• Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurological, or allergic disease (including drug allergies, but excluding untreated, asymptomatic, seasonal allergies at the time of dosing).
• 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 or, in the investigator's judgment, make the participant inappropriate for the study.
• Subjects shown to carry or be positive for HLA-B*1502 or HLA-A*3101 (genotyping alleles/markers related to carbamazepine-associated hypersensitivity reactions, including SJS/TEN).
• Screening supine BP ≥140 mm Hg (systolic) or ≥90 mm Hg (diastolic) for participants <60 years; and ≥150/90 mm/Hg for participants ≥60 years old, following at least 5 minutes of supine rest. If systolic BP is ≥ 140 or 150 mm Hg (based on age) or diastolic ≥90 mm Hg, the BP should be repeated 2 more times and the average of the 3 BP values should be used to determine the participant's eligibility.
• An eGFR <60 mL/min/1.73m², as determined by the CKD-EPI equation using Screat calculated using the recommended formulas
• Standard 12-lead ECG that demonstrates clinically relevant abnormalities that may affect participant safety or interpretation of study results (eg, QTcF >450 ms, complete LBBB, signs of an acute or indeterminate- age myocardial infarction, ST-T interval changes suggestive of myocardial ischemia, second- or third- degree AV block, or serious bradyarrhythmias or tachyarrhythmias). If QTcF exceeds 450 ms, or QRS exceeds 120 ms, the ECG should be repeated twice and the average of the 3 QTcF or QRS values used to determine the participant's eligibility. Computer-interpreted ECGs should be overread by a physician experienced in reading ECGs before excluding a participant.
• Participants with ANY of the following abnormalities in clinical laboratory tests at screening and prior to dosing in each period, as assessed by the study-specific laboratory and confirmed by a single repeat test, if deemed necessary: ALT, AST, Bilirubin ≥1.5 x ULN. Participants with an elevated total bilirubin consistent with Gilberts Disease may have a direct bilirubin measured and would be eligible for this study provided the direct bilirubin level is ≤ ULN.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Period 1; ibuzatrelvir single oral dose on Day 1.	Drug: ibuzatrelvir; 2x 300 mg tablet; Other Names: PF-07817883
Experimental: Period 2; carbamazepine BID oral doses on Day 1-15. ibuzatrelvir single oral dose on Day 14.	Drug: ibuzatrelvir; 2x 300 mg tablet; Other Names: PF-07817883; Drug: carbamazepine ER; 100 mg BID (Day 1-3) 200 mg BID (Day 4-7) 300 mg BID (Day 8-15)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximum Observed Plasma Concentration (Cmax) of ibuzatrelvir		Hour 0, 0.5, 1, 2, 4, 6, 8, 12, 24, 36, 48 post-dose in each period
Area Under the Curve From Time Zero to Extrapolated Infinite Time (AUCinf) of ibuzatrelvir	if data permits	Hour 0, 0.5, 1, 2, 4, 6, 8, 12, 24, 36, 48 post-dose in each period
Area under the plasma concentration-time curve from time 0 to the time of the last quantifiable concentration (AUClast) ofibuzatrelvir		Hour 0, 0.5, 1, 2, 4, 6, 8, 12, 24, 36, 48 post-dose in each period

Secondary Outcome Measures

Outcome Measure	Time Frame
Number of Participants With Treatment Emergent Treatment-Related Adverse Events (AEs)	Baseline (Day 0) up to 35 days after last dose of study medication
Number of Participants With Clinically Significant Change From Baseline in Laboratory Abnormalities	Baseline up to Day 18
Number of Participants With Clinically Significant Change From Baseline in Vital Signs	Baseline up to Day 18

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): October 28, 2024
• Primary Completion (Actual): January 17, 2025
• Study Completion (Actual): January 17, 2025

Study Registration Dates

• First Submitted: October 15, 2024
• First Submitted That Met QC Criteria: October 15, 2024
• First Posted (Actual): October 17, 2024

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: January 31, 2025
• Last Verified: January 1, 2025

More Information

Terms related to this study

• Keywords: Healthy Participants
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Peripheral Nervous System Agents; Central Nervous System Depressants; Sensory System Agents; Analgesics, Non-Narcotic; Analgesics; Sodium Channel Blockers; Membrane Transport Modulators; Tranquilizing Agents; Psychotropic Drugs; Anticonvulsants; Antimanic Agents; Cytochrome P-450 Enzyme Inducers; Cytochrome P-450 CYP3A Inducers; Carbamazepine
• Other Study ID Numbers: C5091009

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