A Safety Study for Previously Treated Vatiquinone (PTC743) Participants With Inherited Mitochondrial Disease

• Vatiquinone (Drug), also known as PTC743: Vatiquinone will be administered per dose and schedule specified in the arm description.

Primary outcomes

• Number of Participants With Treatment-emergent Adverse Events (TEAEs) [Baseline (Day 1) up to 30 days after last dose of study drug (956 days)]: An adverse event (AE) was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. AEs included both serious adverse events (SAEs) and non-serious AEs. A TEAE was defined as an AE that had an onset date or date of worsening on or after the first dose of study drug and within 30 days of the date of the last dose of treatment. A summary of other non-serious AEs and all SAEs, regardless of causality is located in the 'Reported AE section'.

Sex: All

Inclusion Criteria:

* Participants with inherited mitochondrial disease including Leigh syndrome, Alpers syndrome, mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS), myoclonic epilepsy with ragged-red fibers (MERRF), pontocerebellar hypoplasia type 6 (PCH6), or other mitochondrial disease who participated in a previous vatiquinone clinical study or treatment plan.
* Women of childbearing potential must have a negative pregnancy test at screening/baseline and agree to abstinence or the use of at least 1 of the highly effective forms of contraception as specified in the protocol (with a failure rate of <1% per year when used consistently and correctly). Highly effective contraception or abstinence must be continued for the duration of the study, and for up to 30 days after the last dose of study drug.
* Fertile men who are sexually active with women of childbearing potential and who have not had a vasectomy, must agree to use a barrier method of birth control during the study and for up to 30 days after the last dose of study drug.

Exclusion Criteria:

* Current participation in any other interventional study.
* Pregnancy or breast feeding.

Participant flow

Outcome results

• Number of Participants With Treatment-emergent Adverse Events (TEAEs) (Primary), Count of participants, Participants: Vatiquinone 91

Adverse events

Time frame: Baseline (Day 1) up to 30 days after last dose of study drug (956 days)

Serious adverse events by term

2 more terms not shown.

Other adverse events by term

Limitations and caveats: The study was terminated early as PTC discontinued clinical development of vatiquinone for this indication based on prior clinical study results.

• Study Protocol (PDF, 2023-01-25)
• Statistical Analysis Plan (PDF, 2025-04-04)

• Vinay Penematsa, MD, Study director, PTC Therapeutics