Abstract Details

SCA is a rare neurodegenerative disorder without FDA-approved treatments.  Preliminary data from the initial open label phase of Study BHV4157-201 suggested attenuation of disease progression in patients treated with troriluzole.

Provide an assessment of the long term benefit of treatment with troriluzole among patients with Spinocerebellar Ataxia (SCA).

The study was comprised of an 8-week randomization phase, followed by a 48-week open-label phase. An additional 48 weeks of open label was initiated, based on encouraging preliminary data at 1 year.  Subjects were male and female outpatients with the following hereditary ataxias: SCA1, SCA2, SCA3, SCA6, SCA7, SCA8 and SCA10.  The current analysis focused on the continued assessment of change from baseline to 96 weeks in the total SARA score, as well as change in SARA score during gaps in dosing prior to initiation of the additional extension phase.

After up to 96 weeks of open-label treatment with troriluzole, the mean change from baseline in total SARA score (mean change±SE) was 0.3 ± 0.30.  Patients who had a gap in troriluzole treatment (3 weeks to 12 months) while awaiting approval of the protocol extension showed a greater than 1 point worsening during the off-treatment period.  This worsening increased with longer duration off troriluzole. Improvements in total SARA score were observed after re-initiation of troriluzole therapy.

These results are consistent with the initial analysis of the 1-year data showing no increase in SARA score. The observed changes suggest an attenuation of disease progression in patients treated with troriluzole for up to 3 years, including up to a 1-year gap in dosing during which patients declined, versus the expected rate of decline in the SARA in untreated patients of approximately 1-2 points per year, based on cumulative natural history data (Diallo, et al, 2020).