Y-BOCS was a clinician-administered instrument used to assess the severity of obsessive compulsive disorder (OCD) symptoms and to monitor treatment response. The scale included 10 items: 5 items assessed obsessions and 5 items assessed compulsions. Each item was rated from 0 to 4, generating an obsessions subscale score (0-20), a compulsions subscale score (0-20), and a total score ranging from 0 to 40. Higher scores indicated greater OCD symptom severity. Negative change (or reduction in score) indicates improvement.

Modified Intent to Treat (mITT) population included randomized participants who received at least 1 dose of study therapy and had a non-missing baseline assessment and at least one non-missing post-baseline on-treatment efficacy assessment (based on YBOCS in person only) during the randomization phase. Participants with available data were analyzed. As planned, the primary analysis was conducted on the baseline Y-BOCS ≥24 stratification cohort.

An Adverse event (AE) was defined as any new untoward medical occurrence or worsening of a pre-existing medical condition in a participant, that did not necessarily have a causal relationship with treatment. An AE could be any unfavourable/unintended sign including an abnormal laboratory finding, symptom/disease temporally associated with the use of the study drug, whether or not considered related to it. A TEAE was defined as any AE that developed, worsened, or became serious after first dose of test treatment

Safety Population included enrolled participants who received at least one dose of blinded study therapy (troriluzole or placebo).

The SDS was a participant-rated measure of functional disability. SDS was assessed in 3 domains: work/school (0-10), social life (0-10), and family life (0-10). The score from each domain was summed into a single dimensional measure of global functional impairment that ranges from 0 (unimpaired) to 30 (highly impaired). Higher scores indicated a more severe impairment.

mITT population. Participants with available data were analyzed. As planned, the primary analysis was conducted on the baseline Y-BOCS ≥24 stratification cohort.

The CGI-S was a clinician rated assessment of the participants current illness state on a 7-point scale. Scores ranged from 1 (normal, not at all ill) to 7 (among the most extremely ill patients). Higher scores indicated a more severe illness.

mITT population. Participants with available data were analyzed. As planned, the primary analysis was conducted on the baseline Y-BOCS ≥24 stratification cohort.

Y-BOCS was a clinician-administered instrument used to assess the severity of obsessive compulsive disorder (OCD) symptoms and to monitor treatment response. The scale included 10 items: 5 items assessed obsessions and 5 items assessed compulsions. Each item was rated from 0 to 4, generating an obsessions subscale score (0-20), a compulsions subscale score (0-20), and a total score ranging from 0 to 40. Higher scores indicated greater OCD symptom severity. Negative change (or reduction in score) indicates improvement.

mITT population included randomized participants who received at least 1 dose of study therapy and had non-missing baseline assessment and at least one non-missing post-baseline on-treatment efficacy assessment (based on YBOCS in person only) during randomization phase. Participants with available data were analyzed. Additional pre-specified analysis on baseline Y-BOCS = 22 or 23 stratification cohort also conducted.