Safety and tolerability of BHV-7000 as assessed by frequency of unique subjects with SAEs; AEs leading to discontinuation; AEs judged to be related to study medication

To assess the safety and tolerability of BHV-7000. This objective will be measured by assessing the number of unique subjects with grade 3 or 4 laboratory abnormalities.

To assess the safety and tolerability of BHV-7000. This objective will be measured by assessing the number of unique subjects with deaths, SAEs, AEs leading to discontinuation, and moderate and severe AEs.

To assess the safety and tolerability of BHV-7000. This objective will be measured by assessing the number of unique subjects with grade 3 or 4 laboratory abnormalities.

The YMRS is a clinician administered scale that consists of 11 items used to assess the subject's symptoms of mania (total scores range from 0 to 60). The higher the YMRS score, the more severe the subject's symptoms of mania.

The MADRS is a clinician- rated scale to assess depressive symptoms which consists of 10 items. Each item is scored on 7-point scale (0 \[absence of symptoms\] to 6 \[severe\]). A higher score represents a higher severity of the level of depression (total scores range from 0 to 60).

To compare the efficacy of 75mg of BHV-7000 to placebo as an adjunctive therapy for refractory focal onset epilepsy as measured by the change from OP (observational phase) in 28-day average seizure frequency. The primary objective will be measured by comparing the observation phase (8 weeks) to the 8-week double-blind treatment phase.

To compare the efficacy of each of 2 doses of BHV-7000 to placebo as an adjunctive therapy for refractory focal onset epilepsy as measured by the change from OP (observational phase) in 28-day average seizure frequency. The primary objective will be measured by comparing the observation phase (8 weeks) to the 12-week double-blind treatment phase.

To assess the safety and tolerability of BHV-7000. This objective will be measured by assessing the number of unique subjects with deaths, SAEs, AEs leading to discontinuation, and moderate and severe AEs.

To assess the safety and tolerability of BHV-7000. This objective will be measured by assessing the number of unique subjects with grade 3 and 4 laboratory abnormalities.

Participants will be asked to record peak (worst) pain experienced in the previous 2 hours using an 11-point Likert scale (0-10) where 0=no pain and 10=worst possible pain