PTC puts Friedreich ataxia drug's past failures in the rearview with long-term data drop

Several months after forging a fresh path forward for its troubled Friedreich ataxia (FA) drug vatiquinone, PTC Therapeutics is back with some much-needed positive data.

The candidate passed muster by hitting pre-specified endpoints in two separate long-term extension studies, the company said Tuesday, with a “highly statistically significant” and durable effect on disease progression. It means the company is now on track to submit an approval application to the FDA in December, after fine-tuning certain elements of the request.

In the MOVE-FA long-term extension study, vatiquinone yielded a 3.7-point benefit on the modified Friedreich Ataxia Rating Scale (mFARS) at 144 weeks, as compared to a matched natural history cohort from the Friedreich Ataxia Clinical Outcome Measures (FACOMS) disease registry, PTC said. The company suggested that performance plays out to a clinically meaningful 50% slowing in disease progression over the span of three years.

PTC also took a deep dive into long-term data from an earlier vatiquinone study in adults, which showed patients experienced a 4.8-point benefit on the mFARS relative to a matched natural history population at the trial’s two-year mark.

FA is a rare degenerative disease that damages the spinal cord, peripheral nerves and the brain’s cerebellum region. The disease develops in children and teens and worsens over time, leading to movement challenges and loss of sensation.

Aside from the long-term extension data revealed Tuesday—plus mechanistic data showing treatment effect on disease biomarkers—PTC will also bolster its FDA filing with results from the placebo-controlled portion of the MOVE-FA study, with an emphasis on vatiquinone’s benefit on the mFARS’ Upright Stability Subscale.

That subscale formed the foundation of PTC’s appeal to the FDA earlier this year to find a path forward for vatiquinone in FA. At the start of the year, the company had a type C meeting with the regulator to vouch for upright stability data from the phase 3 MOVE-FA study after vatiquinone missed on the mFARS and showed little impact on lower and upper limbs.

“We demonstrated significant benefits on the only thing you possibly could show significant benefit on disease progression, and that's the upright stability scale,” PTC CEO Matthew Klein, M.D., said during an investor briefing back in March.

 

It’s been a long and winding road for vatiquinone up to this point. After reporting the FA miss last summer, PTC shortly thereafter revealed that the drug was no better than placebo in a study of 68 children with mitochondrial disease-associated seizures. That flop prompted the biotech to end development of vatiquinone in the rare seizure disorder.

Following vatiquinone’s prior miss in FA in May 2023, the company cut staff and implemented a pipeline prioritization.