Biohaven has linked troriluzole to a significant slowing of progression in an ultra-rare disease, setting the biotech up to take another shot at winning approval with an asset that the FDA refused to review last year.
Troriluzole failed a phase 3 trial in spinocerebellar ataxia in 2022. Based on talks with the FDA, Biohaven kept tracking patients to compare the effectiveness of the glutamate modulator after three years to external control data.
The new analysis matched 63 patients who completed three years on the study drug to patients who were enrolled in external real-world assessments of outcomes.
Patients on troriluzole performed significantly better than the external controls on f-SARA, a scale that rates gait, stance, sitting and speech in ataxia patients, Biohaven said in a Monday press release. People on troriluzole progressed 50% slower than patients in the U.S. Clinical Research Consortium for the Study of Cerebellar Ataxia (CRC-SCA), the analysis found.
Meanwhile, the speed of progression on troriluzole was 70% slower than in a European natural history study. Biohaven said the 50% to 70% slowdown represents a 1.5- to 2.2-year delay in disease progression over the three-year trial.
Troriluzole performed better than the controls after one and two years of treatment and was statistically superior on nine prespecified primary and secondary endpoints, the biotech said.
Biohaven plans to seek FDA approval for the drug candidate in the fourth quarter and, with troriluzole eligible for priority review, expects to be ready to commercialize the treatment in the U.S. next year. The drug candidate is already under regulatory review in the European Union.
Troriluzole’s trouncing of the external controls shows people taking the molecule performed much better than their matched counterparts. However, that leaves the questions of whether patients were matched to control counterparts with similar baseline health factors, and whether outcomes in the control arms were reflective of the current standard of care.
Biohaven said untreated patients from the CRC-SCA study were “rigorously matched” to treated patients in its trial on baseline characteristics using propensity score matching. CRC-SCA began enrolling patients in 2010 and is still open for recruitment. The European study collected data from 2005 to 2009.
The external controls could come under scrutiny as the FDA reviews the data but, for now, investors are celebrating. Shares in Biohaven rose 15% to $46.50 in premarket trading as the biotech outlined a path to market for troriluzole.
The candidate is also in development in obsessive-compulsive disorder. In that indication, Biohaven is closing in on interim and top-line data from two phase 3 clinical trials.