A Multicenter, Open-label, Pilot Study of Soticlestat (TAK-935/OV935) in Participants With 15Q Duplication Syndrome (Dup 15q) or Cyclin-Dependent Kinase-Like 5 (CDKL5) Deficiency Disorder (ARCADE STUDY)

Seizure frequency per 28 days is defined as total number of Seizures reported during the period divided by number of days with no missing seizure count during the period multiplied by 28. Percent Change from Baseline is defined as (frequency of seizures per 28 days during maintenance period - frequency of seizures per 28 days at Baseline) divided by frequency of seizures per 28 days at Baseline multiplied by 100. Positive percent change from Baseline indicates seizure increase and negative percent change from Baseline indicates seizure decrease.

Seizure frequency per 28 days is defined as total number of Seizures reported during the period divided by number of days with no missing seizure count during the period multiplied by 28. Percent Change from Baseline is defined as (frequency of seizures per 28 days during the treatment period - frequency of seizures per 28 days at Baseline) divided by frequency of seizures per 28 days at Baseline multiplied by 100. Positive percent change from Baseline indicates seizure increase and negative percent change from Baseline indicates seizure decrease.

Responders are defined as having over 50% motor seizure reduction compared to Baseline. Percent reduction from Baseline (%) is defined as [(Maintenance Period motor Seizure Frequency - Baseline Period motor Seizure Frequency) divided by Baseline motor Seizure Frequency] multiplied by 100. Data is reported as reduction of 25%, 50%, 75% and 100% or more in motor seizures from Baseline.

Seizure frequency is defined as total number of Seizures reported during the period divided by number of days with no missing seizure count during the period. Percent Change from Baseline is defined as (frequency of seizures during Treatment period - frequency of seizures at Baseline) divided by frequency of seizures at Baseline multiplied by 100. Positive percent change from Baseline indicates seizure increase and negative percent change from Baseline indicates seizure decrease. The data is reported only for CDD participants.

Seizure-free days is defined as number of days with zero motor seizure during the period the Maintenance Period divided by number of days participant was in the Maintenance Period.

The CGI-S focuses on clinician's observations of the participant's cognitive, functional, and behavioral performance since the beginning of the study. The CGI-S is rated on a 7-point scale, with the severity of illness scale using a range of responses where, 1= normal, not at all ill, 2= borderline mentally ill, 3= mildly ill, 4= moderately ill, 5= markedly ill, 6= severely ill and 7=amongst the most extremely ill participants. Negative change from Baseline indicates improvement.

CGI-Change (CGI-C) treatment response ratings should take account of both therapeutic efficacy and treatment-related AEs. Each component of the CGI is rated separately; the instrument does not yield a global score. The CGI-C is rated on a 5-point scale, where, 0 = marked improvement and no side-effects, 1 = marked improvement and minimal side-effects, 2 = no change, 3 = minimal improvement and marked side-effects and 4 = unchanged or worse and side-effects outweigh the therapeutic effect. Lower scores indicated improvement.

CGI-Change (CGI-C) treatment response ratings should take account of both therapeutic efficacy and treatment-related AEs. Each component of the CGI is rated separately; the instrument does not yield a global score. The CGI-C is rated on a 7-point scale where, 1 = very much improved, 2 = much improved, 3 = slightly improved, 4= no change, 5= slightly worse, 6= much worse and 7= very much worse and marked side-effects. Lower scores indicated improvement.

Seizure Frequency per 28 days is defined as total number of Seizures reported during the period divided by number of days with no missing seizure during the period seizures were assessed multiplied by 28. Positive change from Baseline indicates seizure increase and negative change from Baseline indicates seizure decrease.