In short
Repinatrabit (development code JNT-517) is a chemically synthesised, orally given investigational substance being studied for phenylketonuria (PKU), a rare inherited metabolic condition. It holds orphan designation for this rare disease and has no marketing authorisation yet. One registered Phase 3 trial is currently authorised, planning to enrol 120 participants to compare repinatrabit at two doses against placebo over six weeks of double-blind treatment.
Key points
- Repinatrabit (JNT-517) is an investigational oral tablet with no marketing authorisation.
- It is being studied in phenylketonuria (PKU), a rare inherited metabolic disease.
- The registered trial is a Phase 3 study with a planned enrolment of 120 participants.
- The trial compares repinatrabit 150 mg twice daily against placebo over 6 weeks.
- The main measure is the change in blood phenylalanine levels from baseline to the mean of Weeks 2, 4, and 6.
- The trial is currently authorised in the EU Clinical Trials Information System.
What is repinatrabit?
Repinatrabit, also known by its development code JNT-517, is a chemically synthesised substance developed by Otsuka Pharmaceutical Development & Commercialization, Inc. It is an investigational medicine, meaning it has not yet received a marketing authorisation and is still being studied in clinical trials. The substance has been granted orphan designation for a rare disease, a status given to medicines intended for conditions that affect a small number of people.
How does repinatrabit work?
The registered trial does not describe the mechanism of action of repinatrabit in detail. The primary outcome measures the change in plasma phenylalanine (Phe) levels, which suggests the substance is intended to lower the amount of phenylalanine in the blood of people with phenylketonuria. Phenylketonuria is a condition in which the body cannot properly break down the amino acid phenylalanine, leading to its build-up in the blood.
Which conditions is repinatrabit studied for?
- Phenylketonuria (PKU) — a rare inherited metabolic condition in which the body cannot break down the amino acid phenylalanine, causing it to accumulate in the blood and potentially affect the brain.
How is repinatrabit given?
Repinatrabit is being developed as a film-coated tablet for oral use, meaning it is swallowed. In the registered trial, two dose strengths are being studied: 150 mg and 300 mg, both taken by mouth.
What do the clinical trials show?
One Phase 3 trial of repinatrabit is registered in the EU Clinical Trials Information System, with the identifier 2024-519554-37-00. The trial is currently authorised, meaning it has received regulatory approval to proceed. It plans to enrol 120 participants with phenylketonuria.
The study is designed to assess the efficacy of repinatrabit 150 mg taken twice daily (BID) compared with placebo during six weeks of double-blind treatment. A second dose group of 300 mg is also included in the trial. The main measure is the absolute change in plasma phenylalanine levels from baseline to the mean of Weeks 2, 4, and 6 in the 150 mg twice-daily group. This endpoint tells researchers how much the treatment lowers phenylalanine in the blood over the six-week treatment period.
What side effects are known?
No side effect information is available from the registry data for repinatrabit. As an investigational substance in Phase 3 development, its safety profile is still being evaluated in clinical trials.