Trial Outcomes & Findings for PDC-1421 Treatment in Adult Patients With ADHD (NCT NCT05202327)

NCT ID: NCT05202327

Last Updated: 2026-05-06

Results Overview

The ADHD-RS-IV with Adult Prompts is an 18-item scale based on the DSM-IV-TR criteria for ADHD that provides a rating of the severity of symptoms. The adult prompts serve as a guide to explore more fully the extent and severity of ADHD symptoms and create a framework to ascertain impairment. The odd-numbered 9 items assess inattentive symptoms and the even-numbered 9 items assess hyperactive-impulsive symptoms. Scoring is based on a 4-point, yielding a possible total score of 0-54. Likert-type severity scale: 0 = Never or Rarely, 1 = Sometimes, 2 = Often, 3 = Very Often. Clinicians should score the highest score that is generated for the prompts for each item. The ADHD-RS-IV was assessed from Visit 1 to Visit 7 by the investigator.

Recruitment status

COMPLETED

Study phase

PHASE2

Target enrollment

99 participants

Primary outcome timeframe

8 weeks

Results posted on

2026-05-06

Participant Flow

Participant milestones

Participant milestones
Measure
Placebo
Two placebo capsules thrice daily for 56 days (8 weeks). Placebo: The placebo contained corn starch.
Low-dose
One placebo capsule and 1 PDC-1421 Capsule, thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient. Placebo: The placebo contained corn starch.
High-dose
Two PDC-1421 Capsules thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient.
Overall Study
STARTED
22
23
24
Overall Study
COMPLETED
19
22
19
Overall Study
NOT COMPLETED
3
1
5

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

PDC-1421 Treatment in Adult Patients With ADHD

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Placebo
n=22 Participants
Two placebo capsules thrice daily for 56 days (8 weeks). Placebo: The placebo contained corn starch.
Low-dose
n=23 Participants
One placebo capsule and 1 PDC-1421 Capsule, thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient. Placebo: The placebo contained corn starch.
High-dose
n=24 Participants
Two PDC-1421 Capsules thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient.
Total
n=69 Participants
Total of all reporting groups
Age, Continuous
29.3 years
STANDARD_DEVIATION 8.3 • n=54 Participants
37.3 years
STANDARD_DEVIATION 10.2 • n=60 Participants
33.3 years
STANDARD_DEVIATION 10.8 • n=114 Participants
33.4 years
STANDARD_DEVIATION 10.2 • n=480 Participants
Sex: Female, Male
Female
7 Participants
n=54 Participants
11 Participants
n=60 Participants
16 Participants
n=114 Participants
34 Participants
n=480 Participants
Sex: Female, Male
Male
15 Participants
n=54 Participants
12 Participants
n=60 Participants
8 Participants
n=114 Participants
35 Participants
n=480 Participants
Race (NIH/OMB)
American Indian or Alaska Native
0 Participants
n=54 Participants
0 Participants
n=60 Participants
0 Participants
n=114 Participants
0 Participants
n=480 Participants
Race (NIH/OMB)
Asian
19 Participants
n=54 Participants
20 Participants
n=60 Participants
22 Participants
n=114 Participants
61 Participants
n=480 Participants
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
0 Participants
n=54 Participants
0 Participants
n=60 Participants
0 Participants
n=114 Participants
0 Participants
n=480 Participants
Race (NIH/OMB)
Black or African American
2 Participants
n=54 Participants
0 Participants
n=60 Participants
0 Participants
n=114 Participants
2 Participants
n=480 Participants
Race (NIH/OMB)
White
1 Participants
n=54 Participants
1 Participants
n=60 Participants
2 Participants
n=114 Participants
4 Participants
n=480 Participants
Race (NIH/OMB)
More than one race
0 Participants
n=54 Participants
2 Participants
n=60 Participants
0 Participants
n=114 Participants
2 Participants
n=480 Participants
Race (NIH/OMB)
Unknown or Not Reported
0 Participants
n=54 Participants
0 Participants
n=60 Participants
0 Participants
n=114 Participants
0 Participants
n=480 Participants
Region of Enrollment
United States
3 participants
n=54 Participants
3 participants
n=60 Participants
3 participants
n=114 Participants
9 participants
n=480 Participants
Region of Enrollment
Taiwan
19 participants
n=54 Participants
20 participants
n=60 Participants
21 participants
n=114 Participants
60 participants
n=480 Participants
Weight
67.8 kg
STANDARD_DEVIATION 13.7 • n=54 Participants
72.0 kg
STANDARD_DEVIATION 20.5 • n=60 Participants
63.2 kg
STANDARD_DEVIATION 11.1 • n=114 Participants
67.6 kg
STANDARD_DEVIATION 15.8 • n=480 Participants
Height
170.5 cm
STANDARD_DEVIATION 8.2 • n=54 Participants
167.8 cm
STANDARD_DEVIATION 11.2 • n=60 Participants
166.0 cm
STANDARD_DEVIATION 8.3 • n=114 Participants
168.0 cm
STANDARD_DEVIATION 9.4 • n=480 Participants
BMI
23.2 kg/m2
STANDARD_DEVIATION 3.6 • n=54 Participants
25.2 kg/m2
STANDARD_DEVIATION 4.7 • n=60 Participants
22.9 kg/m2
STANDARD_DEVIATION 3.0 • n=114 Participants
23.7 kg/m2
STANDARD_DEVIATION 3.9 • n=480 Participants

PRIMARY outcome

Timeframe: 8 weeks

The ADHD-RS-IV with Adult Prompts is an 18-item scale based on the DSM-IV-TR criteria for ADHD that provides a rating of the severity of symptoms. The adult prompts serve as a guide to explore more fully the extent and severity of ADHD symptoms and create a framework to ascertain impairment. The odd-numbered 9 items assess inattentive symptoms and the even-numbered 9 items assess hyperactive-impulsive symptoms. Scoring is based on a 4-point, yielding a possible total score of 0-54. Likert-type severity scale: 0 = Never or Rarely, 1 = Sometimes, 2 = Often, 3 = Very Often. Clinicians should score the highest score that is generated for the prompts for each item. The ADHD-RS-IV was assessed from Visit 1 to Visit 7 by the investigator.

Outcome measures

Outcome measures
Measure
Low-dose
n=23 Participants
One placebo capsule and 1 PDC-1421 Capsule, thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient. Placebo: The placebo contained corn starch.
High-dose
n=24 Participants
Two PDC-1421 Capsules thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient.
Placebo
n=22 Participants
Two placebo capsules thrice daily for 56 days (8 weeks). Placebo: The placebo contained corn starch.
Number of Participants With Improvement ≥ 40% in ADHD-RS-IV From Baseline up to 8 Weeks Treatment
9 Participants
10 Participants
11 Participants

SECONDARY outcome

Timeframe: 8 weeks

Clinical Global Impression-Severity (CGI-S) and Clinical Global Impression-Improvement (CGI-I) score of 2 or lower. The CGI-S is rated on a 7-point scale, with the severity of illness scale using a range of responses from 1 (normal) through to 7 (amongst the most severely ill patients). CGI-I scores range from 1 (very much improved) through to 7 (very much worse).

Outcome measures

Outcome measures
Measure
Low-dose
n=23 Participants
One placebo capsule and 1 PDC-1421 Capsule, thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient. Placebo: The placebo contained corn starch.
High-dose
n=24 Participants
Two PDC-1421 Capsules thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient.
Placebo
n=22 Participants
Two placebo capsules thrice daily for 56 days (8 weeks). Placebo: The placebo contained corn starch.
Number of Participants With a CGI Score of 2 or Lower From Baseline up to 8 Weeks Treatment
9 Participants
9 Participants
6 Participants

SECONDARY outcome

Timeframe: 8 weeks

The K-SCT rating scale queries 15 Sluggish Cognitive Tempo symptoms rated from 0 = Never or Rarely, 1 = Sometimes, 2 = Often, 3 = Very Often, grouped into latent factors of daydreaming, working memory problems, and subjective sleepiness/tiredness. The range for the Total Score is 0-45. The higher values represent a worse outcome for the total score and subscore.

Outcome measures

Outcome measures
Measure
Low-dose
n=23 Participants
One placebo capsule and 1 PDC-1421 Capsule, thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient. Placebo: The placebo contained corn starch.
High-dose
n=24 Participants
Two PDC-1421 Capsules thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient.
Placebo
n=22 Participants
Two placebo capsules thrice daily for 56 days (8 weeks). Placebo: The placebo contained corn starch.
Change From Baseline up to 8 Weeks in the Sluggish Cognitive Tempo (K-SCT) Score.
-6.04 score on a scale
Standard Deviation 8.29
-6.54 score on a scale
Standard Deviation 8.04
-5.05 score on a scale
Standard Deviation 8.27

SECONDARY outcome

Timeframe: 8 weeks

The ADHD-RS-IV with Adult Prompts is an 18-item scale base on the DSM-IV-TR criteria for ADHD that provides a rating of the severity of symptoms. The adult prompts serve as a guide to explore more fully the extent and severity of ADHD symptoms and create a framework to ascertain impairment. The odd-numbered 9 items assess inattentive symptoms and the even-numbered 9 items assess hyperactive-impulsive symptoms. Scoring is based on a 4-point, yielding a possible summed "total score" of 0-54. The higher values represent a worse outcome for the total score and subscore. Likert-type severity scale: 0 = Never or Rarely, 1 = Sometimes, 2 = Often, 3 = Very Often.

Outcome measures

Outcome measures
Measure
Low-dose
n=23 Participants
One placebo capsule and 1 PDC-1421 Capsule, thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient. Placebo: The placebo contained corn starch.
High-dose
n=24 Participants
Two PDC-1421 Capsules thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient.
Placebo
n=22 Participants
Two placebo capsules thrice daily for 56 days (8 weeks). Placebo: The placebo contained corn starch.
Change From Baseline up to 8 Weeks in the ADHD-RS-IV Total Scale.
-13.61 score on a scale
Standard Deviation 10.02
-11.75 score on a scale
Standard Deviation 10.20
-12.14 score on a scale
Standard Deviation 10.56

SECONDARY outcome

Timeframe: 8 weeks

The ADHD-RS-IV with Adult Prompts is an 18-item scale base on the DSM-IV-TR criteria for ADHD that provides a rating of the severity of symptoms. The adult prompts serve as a guide to explore more fully the extent and severity of ADHD symptoms and create a framework to ascertain impairment. The odd-numbered 9 items assess inattentive symptoms and the even-numbered 9 items assess hyperactive-impulsive symptoms. Scoring is based on a 4-point, yielding a possible summed "total score" of 0-54, "inattentive subscore" of 0-27, and "hyperactive-impulsive subscore" of 0-27. The higher values represent a worse outcome for the total score and subscore. Likert-type severity scale: 0 = Never or Rarely, 1 = Sometimes, 2 = Often, 3 = Very Often.

Outcome measures

Outcome measures
Measure
Low-dose
n=23 Participants
One placebo capsule and 1 PDC-1421 Capsule, thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient. Placebo: The placebo contained corn starch.
High-dose
n=24 Participants
Two PDC-1421 Capsules thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient.
Placebo
n=22 Participants
Two placebo capsules thrice daily for 56 days (8 weeks). Placebo: The placebo contained corn starch.
Number of Participants With Symptom Remission in ADHD-RS-IV From Baseline up to 8 Weeks Treatment
4 Participants
7 Participants
9 Participants

SECONDARY outcome

Timeframe: 8 weeks

Conners' Adult Attention-Deficit/Hyperactivity Disorder Rating Scale-Self Report: Short Version (CAARS-S:S) consists of 26 items rated from 0=not at all, never to 3=very much, very frequently. Four subscales each composed of 5 items (A: inattention/memory problems; B: hyperactivity/restlessness; C: impulsivity/emotional lability; and D: problems with self-concept) as well as a 12-item ADHD index can be computed. The raw scores were converted into standard T-scores. The higher T-scores represent a better or worse outcome. A T-score is a standard score with a mean of 50 and a standard deviation of 10 in all samples and across all scales

Outcome measures

Outcome measures
Measure
Low-dose
n=23 Participants
One placebo capsule and 1 PDC-1421 Capsule, thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient. Placebo: The placebo contained corn starch.
High-dose
n=24 Participants
Two PDC-1421 Capsules thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient.
Placebo
n=22 Participants
Two placebo capsules thrice daily for 56 days (8 weeks). Placebo: The placebo contained corn starch.
Change From Baseline up to 8 Weeks Treat in the Conners' Adult Attention-Deficit/Hyperactivity Disorder Rating Scale-Self Report: Short Version (CAARS-S:S) ADHD Index of T-score.
-7.43 score on a scale
Standard Deviation 10.20
-7.67 score on a scale
Standard Deviation 9.56
-10.68 score on a scale
Standard Deviation 11.27

Adverse Events

Placebo

Serious events: 0 serious events
Other events: 4 other events
Deaths: 0 deaths

Low-dose

Serious events: 0 serious events
Other events: 6 other events
Deaths: 0 deaths

High-dose

Serious events: 0 serious events
Other events: 8 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure
Placebo
n=22 participants at risk
Two placebo capsules thrice daily for 56 days (8 weeks). Placebo: The placebo contained corn starch.
Low-dose
n=23 participants at risk
One placebo capsule and 1 PDC-1421 Capsule, thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient. Placebo: The placebo contained corn starch.
High-dose
n=24 participants at risk
Two PDC-1421 Capsules thrice daily for 56 days (8 weeks). PDC-1421 Capsule: PDC-1421 Capsule is a botanical investigational new drug containing the extract of Radix Polygalae (Polygala tenuifolia Willd.) as the active ingredient.
Gastrointestinal disorders
DRY MOUTH
0.00%
0/22 • 8 weeks
4.3%
1/23 • Number of events 1 • 8 weeks
8.3%
2/24 • Number of events 2 • 8 weeks
Infections and infestations
COVID-19
0.00%
0/22 • 8 weeks
8.7%
2/23 • Number of events 2 • 8 weeks
12.5%
3/24 • Number of events 3 • 8 weeks
Nervous system disorders
HEADACHE
0.00%
0/22 • 8 weeks
0.00%
0/23 • 8 weeks
8.3%
2/24 • Number of events 2 • 8 weeks
Nervous system disorders
LETHARGY
0.00%
0/22 • 8 weeks
0.00%
0/23 • 8 weeks
8.3%
2/24 • Number of events 2 • 8 weeks
Cardiac disorders
PALPITATIONS
9.1%
2/22 • Number of events 2 • 8 weeks
0.00%
0/23 • 8 weeks
4.2%
1/24 • Number of events 3 • 8 weeks
Cardiac disorders
TACHYCARDIA
0.00%
0/22 • 8 weeks
0.00%
0/23 • 8 weeks
8.3%
2/24 • Number of events 2 • 8 weeks
Gastrointestinal disorders
ABDOMINAL DISTENSION
4.5%
1/22 • Number of events 1 • 8 weeks
8.7%
2/23 • Number of events 2 • 8 weeks
4.2%
1/24 • Number of events 1 • 8 weeks
Gastrointestinal disorders
DIARRHOEA
13.6%
3/22 • Number of events 3 • 8 weeks
4.3%
1/23 • Number of events 2 • 8 weeks
0.00%
0/24 • 8 weeks

Additional Information

Project Manager

BioLite, Inc.

Phone: 886-36579631

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place