Safety, Tolerability, and Pharmacokinetics of Multiple Rising Doses of TAK-137 in Adults With Attention-Deficit/Hyperactivity Disorder.

The purpose of this study is to characterize the safety and tolerability of TAK-137 when administered as multiple oral doses in adults with attention-deficit/hyperactivity disorder (ADHD).

The drug being tested in this study is called TAK-137. TAK-137 is being tested to find a safe and well-tolerated dose and to assess how TAK-137 is metabolized in people with attention-deficit/ hyperactivity disorder (ADHD). This study will look at side effects and lab results in people who take TAK-137. This study is designed as a randomized, sequential-cohort, multiple rising dose study. Therefore, the TAK-137 2 mg Cohort will not start until the TAK-137 0.5 mg Cohort has completed, etc. This trial will be conducted in the United States. The overall time to participate in this study is up to 42 days. Participants will make at least 2 visits to the clinic, including one 9-day period of confinement to the clinic. All participants will be contacted by telephone 7 days after the last dose of study drug for a follow-up assessment. A decision was made to terminate this study so that emerging data from preclinical studies could be further assessed.