Trial Outcomes & Findings for Effect of Tetrabenazine on Stroop Interference in HD (NCT NCT01834911)

NCT ID: NCT01834911

Last Updated: 2025-05-28

Results Overview

Participants will have Stroop Visual Interference Scores measured while OFF tetrabenazine for at least 3 days. Two doses of 12.5 mg tetrabenazine will be subsequently administered: first dose just after the Stroop test and second dose 3 hours later. Stroop Visual Interference Scores will be measured again in the ON state, 6 hours after the initial OFF measurement. Patients are analyzed according to Stroop test using Golden's Interference score (theoretical min -50, theoretical max about 98) calculated from \[(W × C)/(W + C)\] - CW, where C=color score (0-100), W=word score (0-100), CW=color word score (0-100). The Interference score analyzes cognitive interference during trials of reading of a list of color words which are printed in a different color. Lower or more negative scores are clinically better as they indicate less interference.

• Recruitment status: COMPLETED
• Study phase: PHASE4
• Target enrollment: 2 participants
• Primary outcome timeframe: 72 hours
• Results posted on: 2025-05-28

Participant Flow

Participant milestones

Measure	Tetrabenazine Withdrawal Tetrabenazine will be withdrawn for at least 3 days in Huntington disease patients currently taking the medication. Tetrabenazine withdrawal: Tetrabenazine will be withdrawn for at least 3 days in Huntington disease patients currently on the drug. Patients will be examined via Stroop test in the OFF state. Two doses of 12.5 mg tetrabenazine will be introduced, spaced 3 hours apart. Stroop test will be performed 6 hours after initial OFF Stroop test.
Overall Study STARTED	2
Overall Study COMPLETED	2
Overall Study NOT COMPLETED	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Effect of Tetrabenazine on Stroop Interference in HD

Baseline characteristics by cohort

Measure	Tetrabenazine Withdrawal n=2 Participants Tetrabenazine will be withdrawn for at least 3 days in Huntington disease patients currently taking the medication. Tetrabenazine withdrawal: Tetrabenazine will be withdrawn for at least 3 days in Huntington disease patients currently on the drug. Patients will be examined via Stroop test in the OFF state. Two doses of 12.5 mg tetrabenazine will be introduced, spaced 3 hours apart. Stroop test will be performed 6 hours after initial OFF Stroop test.
Age, Categorical <=18 years	0 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	2 Participants n=5 Participants
Age, Categorical >=65 years	0 Participants n=5 Participants
Age, Continuous	57 years n=5 Participants
Sex: Female, Male Female	2 Participants n=5 Participants
Sex: Female, Male Male	0 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	0 Participants n=5 Participants
Race (NIH/OMB) Asian	0 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	0 Participants n=5 Participants
Race (NIH/OMB) Black or African American	0 Participants n=5 Participants
Race (NIH/OMB) White	2 Participants n=5 Participants
Race (NIH/OMB) More than one race	0 Participants n=5 Participants
Race (NIH/OMB) Unknown or Not Reported	0 Participants n=5 Participants
Region of Enrollment United States	2 participants n=5 Participants

PRIMARY outcome

Timeframe: 72 hours

Population: Only 1 patient could complete all conditions of the Stroop test. The delta between on and off Stroop test was 1 using Golden's score \[(W × C)/(W + C)\] - CW

Participants will have Stroop Visual Interference Scores measured while OFF tetrabenazine for at least 3 days. Two doses of 12.5 mg tetrabenazine will be subsequently administered: first dose just after the Stroop test and second dose 3 hours later. Stroop Visual Interference Scores will be measured again in the ON state, 6 hours after the initial OFF measurement.

Patients are analyzed according to Stroop test using Golden's Interference score (theoretical min -50, theoretical max about 98) calculated from [(W × C)/(W + C)] - CW, where C=color score (0-100), W=word score (0-100), CW=color word score (0-100). The Interference score analyzes cognitive interference during trials of reading of a list of color words which are printed in a different color. Lower or more negative scores are clinically better as they indicate less interference.

Outcome measures

Measure	Tetrabenazine Withdrawal n=1 Participants Tetrabenazine will be withdrawn for at least 3 days in Huntington disease patients currently taking the medication. Tetrabenazine withdrawal: Tetrabenazine will be withdrawn for at least 3 days in Huntington disease patients currently on the drug. Patients will be examined via Stroop test in the OFF state. Two doses of 12.5 mg tetrabenazine will be introduced, spaced 3 hours apart. Stroop test will be performed 6 hours after initial OFF Stroop test.
Change in Stroop Interference Score Interference score OFF	-1.97 score on a scale
Change in Stroop Interference Score Interference score ON	-1 score on a scale

Adverse Events

Tetrabenazine Withdrawal

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr. Robert Fekete

New York Medical College

Phone: 9143451313

Email: robert_fekete@nymc.edu

Results disclosure agreements

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