CompletedPhase 1

A Phase I Study To Estimate The Effect Of Ketoconazole And Omeprazole On The Pharmacokinetics Of Dimebon In Healthy Subjects Who Are Normal Or Poor CYP2D6 Metabolizers

A Phase I, Open-Label, Three-Period, Fixed-Sequence Study To Estimate The Steady-State Effect Of Ketoconazole And Omeprazole On The Single-Dose Pharmacokinetics Of Dimebon [PF-01913539] In Healthy CYP2D6 EM And PM Subjects

Lead sponsor

Pfizer

Asset

Dimebon

Listed sites

Recruiting sites

Enrollment

estimated

Study population

Alzheimer’s disease

Key I/E criterion

•Age 18-55

Primary endpoints

•Dimebon alone•Dimebon + keto•Dimebon + omeprazole

Footprint

Where this trial recruits

Site locations as reported to ClinicalTrials.gov. Site count is not enrollment count; per-site enrollment is not available from source.

Identifiers

Registered as

Org study IDB1451017

NCT IDNCT00931073

Timeline

Milestones

Study start2009-07 (month precision)

Study first posted2009-07-02estimated

Primary completion2009-10actual (month precision)

Study completion2009-10actual (month precision)

Last update posted2009-11-18estimated

Assets

Drug assets

Dimebon

Study populations

Who this study enrolls

Alzheimer’s disease

Eligibility

Who can enroll

Minimum age18 Years

Maximum age55 Years

SexAll

Healthy volunteersAccepted

Inclusion criteria

•Subjects who are willing and able to comply with scheduled visits, treatment plan, laboratory tests, and other study procedures.

•Subjects must have either a CYP2D6 EM (n=12) or PM (n=12) status based on genotyping at screening.

•Subjects must have a CYP2C19 EM status based on status at screening

Exclusion criteria

•Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurologic, or allergic disease.

•Subjects with any history of a previous seizure or convulsion or significant head trauma.

•Subjects specifically allergic to imidazole antifungal agents.

•Subjects specifically allergic to omeprazole or other proton pump inhibitors.

•Any condition possibly affecting drug absorption (eg, gastrectomy).

•Subjects with hypersensitivity reactions to Dimebon or other antihistamines.

•Consumption of grapefruit or grapefruit containing products within 7 days prior to the first dose of study medication.

•Subjects currently taking omeprazole, other proton pump inhibitors, antacids, H2-blockers or CYP2C19 inhibitors.

•Pregnant or nursing females; females of childbearing potential who are unwilling or unable to use an acceptable method of nonhormonal contraception as outlined in this protocol from at least 14 days prior to the first dose of study medication.

Endpoints (6)

What's being measured

Protocol endpoints and posted registry outcome measures, grouped into outcome categories. Composite endpoints show their component event types. Standard codes (LOINC, SNOMED CT) are shown where available.

Safety / tolerability / PK

6 endpoints

Primary/protocol endpoint

Dimebon alone: Dimebon PK in CYP2D6 EMs and PMs (Cmax, Tmax, AUCinf (as data permit), AUClast, and t1/2 (as data permit), CL/F (as data permit) and V/F (as data permit))

Time frame:Period 1 Day 1

concentration, descriptive

Primary/protocol endpoint

Dimebon + keto: Dimebon PK in CYP2D6 EMs and PMs (Cmax, Tmax, AUCinf (as data permit), AUClast, and t1/2 (as data permit), CL/F (as data permit) and V/F (as data permit))

Time frame:Period 2 Day 4

concentration, descriptive

Primary/protocol endpoint

Dimebon + omeprazole: Dimebon PK in CYP2D6 EMs and PMs (Cmax, Tmax, AUCinf (as data permit), AUClast, and t1/2 (as data permit), CL/F (as data permit) and V/F (as data permit))

Time frame:Period 3 Day 5

concentration, descriptive

Secondary/protocol endpoint

Dimebon alone: Safety and tolerability (AE's, ECG, vital signs, safety labs)

Time frame:Period 1 Day 1-7

descriptive

Secondary/protocol endpoint

Dimebon + keto: Safety and tolerability (AE's, ECG, vital signs, safety labs)

Time frame:Period 2 Day 1-12

descriptive

Secondary/protocol endpoint

Dimebon + omeprazole: Safety and tolerability (AE's, ECG, vital signs, safety labs)

Time frame:Period 3 Day 1-13

descriptive

Provenance

Sources

Trial identity, design, statusClinicalTrials.gov API v2

Snapshot dateJuly 21, 2026

Endpoint classificationDelfa ADRD endpoint taxonomy

Results tableno registry results posted yet

Trial facts come from public ClinicalTrials.gov records. Endpoint categories are Delfa's classification of those records, not a ClinicalTrials.gov field. All figures reflect the July 21, 2026 snapshot.