The purpose of this expanded access protocol is to provide access to the investigational drug troriluzole in patients with spinocerebellar ataxia (SCA).

This is an Intermediate-Size Patient Population Expanded Access Protocol designed to provide treatment use of troriluzole to patients with spinocerebellar ataxia (SCA) who are considered to be eligible in the clinical judgement of the Investigator/treating physician. The population includes both troriluzole naive patients and patients participating in previous clinical trials with troriluzole (BHV4157-201 and BHV4157-206) who have a confirmed diagnosis of spinocerebellar ataxia.

Key Inclusion Criteria:

• Patient has a confirmed diagnosis of Spinocerebellar Ataxia (SCA), defined as either clinical evidence supporting diagnosis OR confirmed genotypic diagnosis.
• Adequate hepatic function.

Key Exclusion Criteria:

• Patient is known to have acute or chronic liver disease that is clinically significant in the judgement of the Physician.
• Patient has a history of a clinically significant medical condition that would interfere with the patients ability to comply with the expanded access protocol or would place the patient at increased risk.