A Randomized Study of Azetukalner Versus Placebo in Depressive Episodes Associated With Bipolar I or II Disorder (Bipolar Depression)

Key Inclusion Criteria:

• Adults ≥18 and ≤74 years of age who experienced their first major depressive episode (MDE) prior to 50 years of age.

• Body Mass Index (BMI) ≥18 kg/m2 and ≤40 kg/m2.

• Meets the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, TextRevision (DSM-5-TR) criteria for bipolar I or II disorder and is currently in a MDE,confirmed using the Mini International Neuropsychiatric Interview (MINI).

• Current MDE must has a duration of ≥4 weeks and ≤12 months.

Key Exclusion Criteria:

• Participant has any type of major depressive disorder (MDD) diagnosis, including MDDwith psychotic features, MDD with catatonia, MDD with seasonal pattern, orpostpartum depression.

• Participant has any nonbipolar psychiatric diagnosis.

• Participant has a substance use disorder (excluding tobacco) within the 6 monthsprior to screening visit.

• Participant has a symptomatic eating disorder within the 12 months prior toscreening visit.

• Participant has a Young Mania Rating Scale (YMRS) score >12 points at screeningvisit or randomization.

• Participant has been hospitalized for mania within the 30 days prior to screeningvisit.

• Participant is considered treatment-resistant in the current bipolar depressiveepisode, defined as having treatment resistance (no remission) to ≥2 differentmedications approved by the regional regulatory authority at an adequate dose (perregulatory approved label) and for an adequate duration (at least 6 weeks).

• Participant has had an active suicidal plan/intent within the 6 months prior toscreening, presence of suicidal behavior in the last 12 months.

• Participant has self-injurious behavior without intent to die in the 12 months priorto screening.

• Participant has used antidepressants, mood stabilizers, anticonvulsants,antipsychotics, or other prohibited medications within the 1 week or within a periodless than 5 times the drug's half-life, whichever is longer prior to randomization.

• Participants with medical conditions that may interfere with the purpose or conductof the study.

• Participant is pregnant, breastfeeding, or planning to become pregnant.