PTC Reports Late Stage Study Failure of Treatment for Rare Mitochondrial Disease Associated Seizures

Rare Daily Staff

PTC Therapeutics reported that the MIT-E trial of vatiquinone for the treatment of rare mitochondrial disease associated seizures failed to achieve its primary endpoint of reduction in observable motor seizures.

The study showed evidence of treatment effect in reducing seizure frequency in the overall study population and in the largest subgroup of children with Leigh syndrome, in whom benefit was also observed in the key secondary endpoints of occurrence of status epilepticus and disease-related

“While we are disappointed with the results of the study, we hope that there are learnings that can benefit the development of other therapies for patients with mitochondrial disease, who remain without approved treatments for this highly morbid and fatal set of diseases,” said Matthew Klein, CEO of PTC Therapeutics.

The MIT-E study is a double-blind, placebo-controlled study of vatiquinone in pediatric patients with genetically confirmed mitochondrial disease and associated refractory seizures. The study enrolled 68 children at study sites worldwide. The study included a 24-week placebo-controlled phase followed by a 48-week open-label phase. The primary endpoint was the reduction in observable motor seizures during the 24 weeks placebo-controlled phase. All subjects who completed the placebo-controlled phase were eligible to participate in the open-label phase of the study.

Vatiquinone is an investigational new drug that targets 15-lipoxygenase, a regulator of key energetic and oxidative stress pathways. Vatiquinone has been evaluated in a number of clinical studies and has demonstrated an impact on mortality risk and a number of neurological and neuromuscular disease symptoms. The treatment also has extensive safety data, with the longest duration of exposure being over 10 years.

PTC said the MIT-E study results do not support the advancement of vatiquinone for the treatment of MDAS, but plans to discuss the results of the MOVE-FA trial of vatiquinone for the treatment of Friedreich ataxia with regulatory authorities based on signals of clinical benefit on key subscales of the mFARS, such as upright stability, even though that study also failed to meet the primary endpoint.

Photo: Matthew Klein, CEO of PTC Therapeutics