Repinatrabit's effects on common medicines like birth control, metformin, carbamazepine, rosuvastatin, and methotrexate

A Phase 1, 4-arm, Open-label, Drug-drug Interaction Trial to Evaluate the Pharmacokinetics of Repinatrabit Oral Tablets When Co-administered With Ethinyl Estradiol/Norethindrone, Metformin, Carbamazepine, Rosuvastatin, and Methotrexate in Healthy Participants

This trial will test whether repinatrabit changes how common medicines—ethinyl estradiol/norethindrone (birth control), metformin, carbamazepine, rosuvastatin, and methotrexate—act in healthy adults.

Quick facts

• Phase: Phase 1
• Study type: Interventional
• Enrollment: 48 (estimated)
• Ages: 18 Years to 55 Years
• Sex: All
• Sponsor: Otsuka Pharmaceutical Development & Commercialization, Inc. (Industry-sponsored)
• Drugs / interventions: methotrexate
• Locations: 1 site (Melbourne, Victoria)
• Trial ID: NCT07446400 on ClinicalTrials.gov

What this trial studies

This is a Phase 1 interventional drug–drug interaction trial in healthy volunteers designed to measure how repinatrabit affects the blood levels and behavior of several commonly used medicines. Participants receive repinatrabit together with each listed concomitant medication in controlled clinic visits while investigators collect blood samples, ECGs, and routine labs to monitor drug concentrations and safety. The trial enrolls adults with BMI 18–35 kg/m2 who pass screening exams and laboratory tests; one arm specifically enrolls biological females for the ethinyl estradiol/norethindrone pairing. Safety follow-up includes clinic observation and telephone contact after dosing.

Who should consider this trial

Good fit: Healthy adults (BMI 18–35 kg/m2) who meet screening labs and exam criteria, can stay in the clinic for required visits, and are non‑childbearing females or males as specified by the protocol.

Not a fit: People seeking treatment for a medical condition are unlikely to receive direct therapeutic benefit because this is a healthy‑volunteer drug interaction study.

Why it matters

Potential benefit: If successful, the results could clarify safe co‑use of repinatrabit with these medicines and guide prescribing decisions to reduce the risk of interactions.

How similar studies have performed: Drug–drug interaction studies are a routine and well‑established part of drug development and have successfully identified interaction risks for many medications, though repinatrabit-specific interaction data are limited.

Eligibility criteria

Inclusion Criteria:

1. Body mass index (BMI) from 18 to 35 kilograms per square meter (kg/m\^2) (inclusive).
2. Male and female (of non-childbearing potential) assigned at birth, inclusive of all gender identities. Arm 1 will only recruit biological females.
3. In good health as determined by:

   1. Medical history
   2. Physical examination
   3. ECG
   4. Serum chemistry, urinalysis, hematology, and serology tests
4. Willing to stay in the clinic for the required period and willing to be contacted for the safety follow-up via telephone contact.
5. Ability to provide written, informed consent prior to initiation of any trial-related procedures, and ability, in the opinion of the principal investigator, to comply with all the requirements of the trial.

Exclusion Criteria:

1. Female participants of childbearing potential.
2. Female participants who have used HRT within 60 days or hormonal contraceptives within 14 days prior to Day 1 (Arm 1 only).
3. Clinically significant abnormality in past medical history, or at the screening physical examination, that in the investigator's or sponsor's opinion may place the participant at risk or interfere with outcome variables including absorption, distribution, metabolism, and excretion of drug. This includes, but is not limited to, history of or concurrent cardiac, hepatic, renal, neurologic, endocrine, gastrointestinal, respiratory, hematologic, and immunologic disease or cholecystectomy.
4. For Arm 3, participants who test positive for HLA haplotypes associated with carbamazepine-induced hypersensitivity (HLA-B\*15:02, HLA-A\*31:01, and HLA-B\*15:11).

Note: Other protocol-specified Inclusion/Exclusion criteria may apply.

Where this trial is running

Melbourne, Victoria

• Nucleus Network — Melbourne, Victoria, Australia (Recruiting)

Study contacts

• Study coordinator: Otsuka Call Center

Conditions Healthy Volunteers; Phenylketonuria; Drug-Drug Interaction study