A Study of PDC-1421 Treatment in Adult Patients With Attention-Deficit Hyperactivity Disorder (ADHD)

The primary objective of this trial was to determine the effective doses and treatment period of PDC-1421 Capsule in subjects with ADHD.

The secondary objective was to evaluate the safety of PDC-1421 Capsule in subjects receiving PDC-1421 at various dose levels.

This study was a Part I of Phase II study designed to evaluate the safety and efficacy in adult patients with ADHD. The Screening phase is intended for diagnosing and assessing the patient for possible inclusion in the study and for providing an adequate washout period. The targeted population of this Part I study is six subjects who met the intent-to-treat per-protocol basis.

Part I study is an open-label study, single-center, and dose escalation evaluation in six patients.

1. Low dose: Six subjects will be initially evaluated for safety and efficacy assessments at low-dose (1 PDC-1421capsule TID) for 28 days. The subject will return for visit once a week during the treatment period.
2. Checkpoint #1: There will be an evaluation with all safety assessments data to decide whether subjects pass the checkpoint to enter high-dose treatment or continue to receive a low-dose treatment by the investigator.
3. High dose: The subjects who pass Checkpoint #1 will be initially evaluated for safety and efficacy assessments at high-dose (2 PDC-1421 capsules TID) for 28 days. Subjects will return for visit biweekly during the treatment period.
4. Checkpoint #2: There will be an evaluation with all safety assessments data to decide whether this study passes the checkpoint to enter Part II by the investigators.

Eligibility Criteria:
Inclusion Criteria:

1. Aged 18-70 years
2. Female subjects of child-bearing potential must test negative to pregnancy and use appropriate birth control method from the beginning of study to the 15 days later after ending of study
3. Subjects must be able to understand and willing to sign informed consent
4. Able to discontinue the use of any psychotropic medications for the treatment of ADHD symptoms at screening
5. Meet strict operational criteria for adult ADHD according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5)
6. A total score of 20 or higher on the 18-item total ADHD symptoms score of Conners' Adult Attention-Deficit/Hyperactivity Disorder Rating Scale-Self Report: Short Version (CAARS-S:S) at screening
7. Have a moderate or severe symptom of ADHD with score of 4 or higher in Clinical Global Impression-ADHD-Severity (CGI-ADHD-S) at screening

Exclusion Criteria:

1. Have any clinically significant concurrent medical condition (endocrine, renal, respiratory, cardiovascular, hematological, immunological, cerebrovascular, neurological, anorexia, obesity or malignancy) that has become unstable and may interfere with the interpretation of safety and efficacy evaluations
2. Have any clinically significant abnormal laboratory, vital sign, physical examination, or electrocardiogram (ECG) findings at screening that, in the opinion of the investigator, may interfere with the interpretation of safety or efficacy evaluations
3. Have known serological evidence of human immunodeficiency virus (HIV) antibody
4. Are pregnant as confirmed by a positive pregnancy test at screening
5. Have QTc values \>450 msec at screening using Fridericia's QTc formula
6. Have current of bipolar and psychotic disorders
7. Have a current major depression disorder, obsessive-compulsive disorder, post-traumatic stress disorder, generalized anxiety disorder, panic disorder and eating disorder (also if treated but not currently symptomatic)
8. Have any history of a significant suicide attempt, or possess a current risk of attempting suicide, in the investigator's opinion, based on clinical interview and responses provided on the Beck Scale for Suicidal Ideation (BSS)
9. Have a history of jailing or imprisonment in the past 6 months due to worsening of symptoms of ADHD