A Study to Compare the Amount of Two Forms of Tafamidis in the Blood of Healthy Adults Under Fed Conditions

A PHASE 1, OPEN-LABEL, RANDOMIZED, CROSSOVER, SINGLE DOSE, PIVOTAL BIOEQUIVALENCE STUDY TO COMPARE TAFAMIDIS FREE ACID TABLET AND COMMERCIAL TAFAMIDIS FREE ACID CAPSULE ADMINISTERED UNDER FED CONDITIONS IN HEALTHY ADULT PARTICIPANTS

The purpose of this clinical trial is to compare the amount of tafamidis in the blood of healthy adult participants after taking two different forms of tafamidis by mouth under fed conditions.

Study Overview

• Status: Recruiting
• Conditions: Healthy
• Intervention / Treatment: Drug: Tafamidis (Reference); Drug: Tafamidis (Test)

Detailed Description

This study will be a Phase 1, open-label, randomized, two-treatment, two-period, crossover, single dose bioequivalence study to compare 61 mg tafamidis free acid tablet (Test) to 61 mg tafamidis free acid capsule (Reference) administered under fed conditions in healthy adult participants.

• 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

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

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria

Age and Sex:

1. 18 years of age or older (or the minimum age of consent in accordance with local regulations) at screening who are overtly healthy as determined by medical evaluation including medical history, physical examination, laboratory tests, and cardiac monitoring.

   Other Inclusion Criteria:

2. BMI of 16-32 kg/m2; and a total body weight >45 kg (99 lb).
3. Evidence of a personally signed and dated informed consent document indicating that the subject has been informed of all pertinent aspects of the study.

Exclusion Criteria

Medical Conditions:

1. 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 condition possibly affecting drug absorption (eg, gastrectomy, cholecystectomy).
   • History of HIV infection, hepatitis B, or hepatitis C; positive testing for HIV, HBsAg, HBcAb or HCVAb. Hepatitis B vaccination is allowed.
   • Hypersensitivity to any component of the formulations.

2. Any medical or psychiatric condition including any active suicidal ideation in the past year or suicidal behavior in the past 5 years 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.

   Prior/Concomitant Therapy:

3. Use of prescription or nonprescription drugs and dietary and herbal supplements within 7 days or 5 half-lives (whichever is longer) prior to the first dose of study intervention.

4. Use of any prohibited concomitant medication(s) or unwillingness or inability to use a required concomitant medication(s).

   Prior/Concurrent Clinical Study Experience:

5. Previous administration of an investigational product (drug or vaccine) within 30 days or 5 half-lives preceding the first dose of study intervention used in this study (whichever is longer). Participation in studies of other investigational products (drug or vaccine) at any time during participation in this study.

   Diagnostic Assessments:

6. A positive urine drug test. A single repeat for positive drug screen may be allowed.
7. 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.
8. Renal impairment as defined by eGFR <60 mL/min/1.73 m², which may be confirmed by a single repeat test, if necessary.
9. Standard 12-lead ECG that demonstrates clinically relevant abnormalities that may affect participant safety or interpretation of study results (including, but not limited to, QTcF >450 ms, complete LBBB, signs of an acute or indeterminate- age myocardial infarction, ST segment and/or T wave 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 an investigator experienced in reading ECGs before excluding a participant.

10. Participants with ANY of the following abnormalities in clinical laboratory tests at screening, as assessed by the study-specific laboratory and confirmed by a single repeat test, if deemed necessary:

    • ALT, AST, Bilirubin ≥1.5× ULN. Participants with a history of Gilbert's syndrome may have direct bilirubin measured and would be eligible for this study provided the direct bilirubin level is ≤ ULN.

    Other Exclusion Criteria:

11. History of alcohol abuse or repeated binge drinking and/or any other illicit drug use or dependence within 6 months of screening. Binge drinking is defined as a pattern of 5 (male) and 4 (female) or more alcoholic drinks in about 2 hours. As a general rule, alcohol intake should not exceed 14 units per week (1 unit = 8 ounces (240 mL) beer, 1 ounce (30 mL) of 40% spirit, or 3 ounces (90 mL) of wine).
12. Unwilling or unable to comply with the criteria in the Lifestyle Considerations section of this protocol.
13. Investigator site staff directly involved in the conduct of the study and their family members, site staff otherwise supervised by the investigator, and sponsor and sponsor delegate employees directly involved in the conduct of the study and their family members.
14. Use of tobacco/nicotine containing products in excess of the equivalent of 5 cigarettes/day or 2 chews of tobacco/day.

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

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Reference capsule followed by Test tablet; On Day 1 of each period, participants will receive a single dose of 1 of the tafamidis formulations. Each period is separated by a washout of at least 16 days between administration of study drug.	Drug: Tafamidis (Reference); 61 milligrams (mg) free acid capsule; Drug: Tafamidis (Test); 61 mg free acid tablet
Experimental: Test tablet followed by Reference capsule; On Day 1 of each period, participants will receive a single dose of 1 of the tafamidis formulations. Each period is separated by a washout of at least 16 days between administration of study drug.	Drug: Tafamidis (Reference); 61 milligrams (mg) free acid capsule; Drug: Tafamidis (Test); 61 mg free acid tablet

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Area under the concentration-time curve (AUCinf)	Area under the plasma concentration time profile from time zero extrapolated to infinite time.	Hour 0, 0.5, 1, 2, 3, 4, 6, 8, 12, 24, 48, 72, 96, 120, 144, 168.
Maximum observed plasma concentration (Cmax)	Peak or maximum observed concentration.	Hour 0, 0.5, 1, 2, 3, 4, 6, 8, 12, 24, 48, 72, 96, 120, 144, 168

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number or percentage of patients with change from baseline in Clinical Laboratory parameters	Change in clinical laboratory parameters	Baseline up to Day 25
Number or percentage of patients with abnormal physical examination findings	Assessment of abnormal physical examination findings during study participation	Baseline up to Day 53
Number or percentage of patients with change from baseline in vital sign measurements	Change in vital sign measurements	Baseline up to Day 25
Number of patients with change in electrocardiogram (ECG) parameters	Change in ECG parameters	Baseline up to Day 25
Incidence of adverse events	Assessment of adverse events during study participation and up to 35 days after last dose	Baseline up to Day 53 (35 days after last dose)

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): March 23, 2026
• Primary Completion (Estimated): June 2, 2026
• Study Completion (Estimated): June 2, 2026

Study Registration Dates

• First Submitted: March 10, 2026
• First Submitted That Met QC Criteria: March 10, 2026
• First Posted (Actual): March 13, 2026

Study Record Updates

• Last Update Posted (Actual): April 24, 2026
• Last Update Submitted That Met QC Criteria: April 21, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Tafamidis
• Additional Relevant MeSH Terms: tafamidis
• Other Study ID Numbers: B3461131; 2026-525342-29-00 (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