Potential Spinocerebellar Ataxia Therapy Granted Priority Review and Is Available Through an Expanded Access Protocol

The Food and Drug Administration (FDA) has accepted the New Drug Application (NDA) for troriluzole (Biohaven, New Haven, CT), an investigational glutamate modulator for the treatment of spinocerebellar ataxia (SCA). Troriluzole also was granted Priority Review by the agency, with a Prescription Drug User Fee Act (PDUFA) action date set for August 15, 2025. If the NDA is approved, troriluzole would become the first FDA-approved treatment for SCA.

The NDA submission is supported by topline data from a phase 3 real-world evidence (RWE) study (NCT06529146), in which patients with SCA received treatment with oral troriluzole 200 mg once daily for 3 years. Treatment efficacy was assessed in comparison with a matched natural history cohort of people with SCA.

• Troriluzole met the study’s primary endpoint in all SCA genotypes, defined as a change from baseline on the functional Scale for the Assessment and Rating of Ataxia (f-SARA) at 3 years vs the natural history cohort.
• Participants with SCA who received troriluzole showed 50% to 70% slower decline in disease progression (equivalent to a delay of 1.5 to 2.2 years) compared with the natural history cohort.
• Across all genotypes, troriluzole treatment was associated with a reduction in falls as compared with the natural history cohort.

SCA comprises a group of rare, genetic, neurodegenerative conditions affecting approximately 15,000 people in the United States, marked by progressive cerebellar degeneration and loss of voluntary motor control leading to progressive disability and premature death. Current care is limited to symptomatic treatment, assistive devices, and physical therapy.

“The delay in disease decline shown in the real-world evidence study is a watershed in the history of the SCAs. This is what patients have been waiting for. It is what the doctors who have been powerless, have been waiting for,” said Jeremy Schmahmann, MD, Professor of Neurology at Harvard Medical School, Founding Director of the Ataxia Center, and Robert Fogelman Endowed Chair in Ataxia and Cerebellar Neurology at Massachusetts General Hospital. “Additionally, the importance of troriluzole's effects on reducing falls in this patient population cannot be overstated. I applaud the FDA for recognizing this urgency by granting a Priority Review and look forward to using troriluzole in the clinic if approved."

Troriluzole was previously granted Orphan Drug Designation (ODD) and Fast Track Designation (FTD) by the FDA. An expanded access protocol (EAP) study (NCT06034886) is currently available for patients with SCA, enabling early access to treatment with troriluzole.