Study of TAK-935 as an Adjunctive Therapy in Participants With Developmental and/or Epileptic Encephalopathies
Study of TAK-935 as an Adjunctive Therapy in Participants With Developmental and/or Epileptic Encephalopathies
The purpose of this study is to characterize the multiple-dose safety and tolerability
 profile of TAK-935 in adult participants with developmental and/or epileptic
 encephalopathies.
The drug being tested in this study is called TAK-935. TAK-935 is being tested to treat
 people who have developmental and/or epileptic encephalopathies. This study will look at
 safety, tolerability and pharmacokinetics of people who take TAK-935. Study drug will be
 administered in a double-blind manner in Part 1 and in an open-label manner in Part 2.

 The study will enroll approximately 20 participants. Participants will be randomly assigned
 (by chance, like flipping a coin) to one of the two treatment groups in Part 1-which will
 remain undisclosed to the participant and study doctor during the study (unless there is an
 urgent medical need):

 -  TAK-935

 -  Placebo (dummy inactive pill) - this is a tablet that looks like the study drug but has
 no active ingredient

 Participants will receive placebo or 100 milligram (mg) TAK-935 tablets, orally or through
 stable G-tube/PEG tube, BID, in Part 1 (Day 1) and dose will be increased to 200 mg (Day 11)
 BID and to 300 mg (Day 21) BID in dose titration period. All participants who complete the
 Double-Blind Treatment Period in Part 1 will have the option to continue directly into the
 Open-Label Treatment Period in Part 2 where they will receive TAK-935 as two 100 mg tablets
 (total dose is 200 mg TAK-935) orally or through G-tube/PEG tube, BID and dose will be
 increased to three 100 mg tablets (total dose is 300 mg TAK-935), orally, BID (Day 41). This
 dose level will be maintained until the final visit (Day 85) for the dose de-escalation
 phase.

 This multi-center trial will be conducted in North America. The overall time to participate
 in this study is 121 days excluding screening period of 30-41 days. Participants will make
 multiple visits to the clinic, and a follow-up phone call will be conducted on Day 91 and at
 the end of the 30-day follow-up period (Day 121), participants will return to the clinic for
 a follow-up assessment.
Inclusion Criteria:

 1. Has a documented clinical diagnosis of developmental and/or epileptic encephalopathies
 with countable bilateral motor seizures, defined as an average of greater than or
 equal to (>=) 2 per month during the past 3 months, based on the investigator's
 assessment, and a monthly average of >=1 per month during the Baseline Period, based
 on the seizure diary record.

 2. Has been taking 1 to 4 antiepileptic drug (AEDs) at a stable dose for >=4 weeks before
 Screening and the participant or participant's legally acceptable representative is
 willing to keep the regimen(s) stable throughout the study.

 3. Has an average of >=1 bilateral motor seizure per month during the 4-week Baseline
 Period (that is., drop seizures, tonic-clonic, tonic, bilateral clonic, atonic,
 myoclonic-atonic, myoclonic-tonic-clonic, focal seizures with bilateral hyperkinetic
 motor features).

 4. Must agree to not post any participant's personal medical data related to the study or
 information related to the study on any web site or social media site (example,
 Facebook, Twitter) until the study has been completed.

 5. For participants with G-tube/PEG tube, G-tubes/PEG tubes should have been placed and
 been functioning for at least 3 months prior to screening. Naso-gastric tubes are not
 allowed.

 Exclusion Criteria:

 1. Has received TAK-935 in a previous clinical study or as a therapeutic agent.

 2. Was admitted to a medical facility for treatment of status epilepticus requiring
 mechanical respiration within 3 months before Screening.

 3. Had a vagal nerve stimulator implanted within 6 months before Screening and settings
 have been changed within 1 month of the Screening Visit and/or anticipated to change
 during the study.

 4. Is on ketogenic diet that has been started within 6 months of the Screening Visit, has
 been changed within 1 month of the Screening Visit, or is anticipated to change during
 the study.

 5. Has degenerative eye disease.

 6. Has a history of suicidal behavior or any suicidal ideation of type 4 or 5 on the
 Columbia-Suicide Severity Rating Scale (C-SSRS) at Screening. If the participant is
 unable to comply with the C-SSRS due to developmental status, a parent proxy may be
 used for the completion of the C-SSRS. The Investigator may also use clinical
 judgment, which must then be documented in the source document.

 7. Positive for human immunodeficiency virus, hepatitis B, or hepatitis C infections.
 (Note that participants who have been vaccinated against hepatitis B [hepatitis B
 surface antibody (Ab)-positive] who are negative for other markers of prior hepatitis
 B infection [example, negative for hepatitis B core Ab] are eligible. Also note that
 participants who are positive for hepatitis C Ab are eligible as long as they have a
 negative hepatitis C viral load by quantitative polymerase chain reaction [qPCR]).

 8. Has an abnormal and clinically significant ECG at Screening in the opinion of the
 investigator, for example, second or third degree heart block or a corrected QT
 interval (QTc) greater than (>) 450 millisecond (msec). Entry of any participant with
 an abnormal but not clinically significant ECG must be approved and documented by
 signature by the principal investigator or appropriately qualified delegate.

 9. Has abnormal clinical laboratory test results at Screening that suggest a clinically
 significant underlying disease. If the participant has alanine aminotransferase (ALT)
 and/or aspartate aminotransferase (AST) >2.5*the upper limit of normal (ULN), the
 Medical Monitor should be consulted.

 10. Has received any excluded medications, procedures, or treatments during the time
 periods.

 11. Has any a history of alcohol, opioid, or other drug use disorder, as per the
 Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, within the
 previous 2 years before Screening. Medical marijuana use is allowed.

 12. Has unstable, clinically significant neurologic (other than the disease being
 studied), psychiatric, cardiovascular, pulmonary, hepatic, renal, metabolic,
 gastrointestinal, urologic, immunologic, hematopoietic, or endocrine disease or other
 abnormality, which may impact the ability of the participant to participate or
 potentially confound the study results.