Biohaven Pharmaceutical has initiated patient enrolment in a Phase III clinical trial of its third-generation prodrug troriluzole for the treatment of spinocerebellar ataxia (SCA).
SCA is a rare, potentially fatal neurodegenerative disorder characterised by difficulties with balance, speech, and coordination. The condition is believed to be due to different autosomal dominant genetic mutations.
No US Food and Drug Administration (FDA)-approved treatment for SCA is currently available.
Troriluzole is designed to modulate the excitatory glutamate neurotransmitter. It reduces synaptic levels of glutamate by increasing its uptake via augmentation of the expression and function of excitatory amino acid transporters.
The new Phase III trial will assess the safety and efficacy of the drug over 48 weeks in around 230 subjects with a diagnosis of SCA types 1, 2, 3, 6, 7, 8, and 10.
Biohaven is conducting the randomised, double-blind, placebo-controlled study at 22 centres across the US.
The trial’s primary outcome measure is a change in a patient's score on a scale intended to evaluate the severity of SCA symptoms.
Biohaven Ataxia development programme medical lead Melissa Wolfe Beiner said: “Based on learnings from our previous Phase IIb/III clinical trial, we have enriched this trial with specific genotypes, extended the treatment period of this trial to one year, implemented the use of a modified SARA scale and increased the dose of troriluzole to 200mg.
“We believe that these changes may improve the ability of the trial to more accurately evaluate troriluzole's benefit in slowing disease progression in patients with SCA.”
The Phase IIb/III trial compared troriluzole in SCA patients to those selected from a natural history cohort and matched on multiple eligibility criteria. It included a short-term randomisation and long-term extension phase.