BHV-4157 in Adult Subjects With Obsessive Compulsive Disorder

Inclusion Criteria:

1. Primary diagnosis of obsessive-compulsive disorder (OCD) as per Diagnostic and
Statistical Manual of Mental Disorders.

2. Subjects must be currently experiencing non-response or inadequate response to their
current Standard of Care (SOC) medication defined as:

1. Subjects Y-BOCS total score must be ≥ 19 at Screening and Baseline, reflecting
moderate or severe OCD symptoms.

2. Subjects must currently be on a selective serotonin reuptake inhibitor (SSRI),
clomipramine, venlafaxine or desvenlafaxine.

3. Determined by the investigator to be medically stable at baseline/randomization as
assessed by medical history, physical examination, laboratory test results, and
electrocardiogram testing. Subjects must be physically able and expected to complete
the trial as designed;

4. Minimum of 6 years of education or equivalent and sufficiently fluent in English to
complete necessary scales and understand consent forms;

5. Subjects must have adequate hearing, vision, and language skills to perform
neuropsychiatric testing and interviews as specified in the protocol;

6. Subjects must be able to understand and agree to comply with the prescribed dosage
regimens and procedures; report for regularly scheduled office visits; and reliably
communicate with study personnel about adverse events and concomitant medications;

7. It is required that all women of child-bearing potential (WOCBP) who are sexually
active agree to use two methods of contraception for the duration of the study (i.e.
beginning 30 days prior to baseline and extending to 30 days after the last dose of
study drug).

8. Women of childbearing potential must have a negative serum pregnancy test at screening
and a negative urine pregnancy test prior to dosing at Baseline;

9. It is required that men who are sexually active with WOCBP agree to use two methods of
contraception for the duration of the study (beginning at first treatment and
extending to 90 days after the last dose of study drug).

Exclusion Criteria:

1. Subjects should be excluded with a history of more than two (2) previous failed
treatment trials of SSRIs, clomipramine, venlafaxine, or desvenlafaxine (not including
the current SSRI trial) given for an adequate duration at an adequate dose as defined
by the following criteria taken from the MGH-TRQ-OCD as:

1. Treatment failure / non-response: As per the MGH-TRQ-OCD, there has been minimal
or no meaningful clinical benefit as perceived by the patient despite an adequate
dose and duration of treatment;

2. Adequate duration: At least 10 weeks of treatment with SSRI, clomipramine,
venlafaxine, or desvenlafaxine

3. Adequate dose: Defined by the USPI labeling.

2. Current or prior history, per DSM-V criteria, of bipolar I or II disorder,
schizophrenia or other psychotic disorders, schizoaffective disorder, autism or
autistic spectrum disorders, borderline personality disorder, antisocial personality
disorder, body dysmorphic disorder, hoarding disorder (symptoms of hoarding disorder
as part of the OCD diagnosis are allowed, but a primary diagnosis of hoarding disorder
is excluded); a current diagnosis of Tourette's disorder is also excluded;

3. Any eating disorder within the last 12 months;

4. Acute suicidality or suicide attempt or self-injurious behavior in the last 12 months;

5. History of psychosurgery, Deep Brain Stimulation (DBS) or Electroconvulsive Therapy
(ECT).

6. Transcranial Magnetic Stimulation (TMS) is prohibited within three months prior to
screening and during the study.