['dementia with lewy bodies', 'rem sleep behavior disorder', "parkinson's disease dementia"]
['nelotanserin', 'placebo']

        Inclusion Criteria:

          -  Adult subjects at least 50 years of age, with a diagnosis of DLB or PDD and RBD based
             on Diagnostic and Statistical Manual of Mental Disorders Fifth Edition (DSM-5)
             diagnostic criteria

          -  Presence of frequent REM sleep behavior episodes

          -  Mini Mental State Examination score ≥ 18

        Exclusion Criteria:

          -  Subjects have a current diagnosis of significant psychotic disorders including, but
             not limited to, schizophrenia or bipolar disorder

          -  Subjects' RBD symptoms are secondary to or better accounted for by another medical
             condition, psychiatric disorder, or substance abuse

          -  Subjects with a current serious and/or unstable cardiovascular, respiratory, thyroid,
             gastrointestinal, renal, hematologic or other medical disorder
      