Trial Outcomes & Findings for The Effect of Horizant (Gabapentin Enacarbil) on Augmentation (NCT NCT02642315)

NCT ID: NCT02642315

Last Updated: 2022-02-24

Results Overview

Augmentation severity rating scale; 0-24, 0 is better, 24 is worst

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 10 participants
• Primary outcome timeframe: From Day 0 (Baseline) to Day 90
• Results posted on: 2022-02-24

Participant Flow

Participant milestones

Measure	Open-label open-label single arm study Horizant, 600 mg oral once daily at 5 pm for 360 days. Horizant: Phase1: During phase 1 therapy, Horizant will be added on as an adjunct to all subjects taking part in the study along with stable dose of their current dopaminergic (DA) agent and both medication will be continued for a total period of 90 days from day 0 to day 90. Subjects will be evaluated for three visits (days 0, 30 and 90) during Phase I. Phase 2: At the 90th day follow-up visit, with initiation of phase 2 therapy, all subjects will be tapered off (by 50% reduction in dose each week) of their current dopaminergic agents while maintaining the same dose of Horizant and will be on Horizant monotherapy. All subjects will be evaluated for additional three clinic visits (days 120, 180, 360).
Overall Study STARTED	10
Overall Study COMPLETED	8
Overall Study NOT COMPLETED	2

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

The Effect of Horizant (Gabapentin Enacarbil) on Augmentation

Baseline characteristics by cohort

Measure	Open-label n=10 Participants open-label single arm study Horizant, 600 mg oral once daily at 5 pm for 360 days. Horizant: Phase1: During phase 1 therapy, Horizant will be added on as an adjunct to all subjects taking part in the study along with stable dose of their current dopaminergic (DA) agent and both medication will be continued for a total period of 90 days from day 0 to day 90. Subjects will be evaluated for three visits (days 0, 30 and 90) during Phase I. Phase 2: At the 90th day follow-up visit, with initiation of phase 2 therapy, all subjects will be tapered off (by 50% reduction in dose each week) of their current dopaminergic agents while maintaining the same dose of Horizant and will be on Horizant monotherapy. All subjects will be evaluated for additional three clinic visits (days 120, 180, 360).
Age, Continuous	54 years n=5 Participants
Sex: Female, Male Female	6 Participants n=5 Participants
Sex: Female, Male Male	4 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	10 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
IRLS score	22.5 units on a scale n=5 Participants
Augmentation Severity rating scale	7.5 units on a scale n=5 Participants

PRIMARY outcome

Timeframe: From Day 0 (Baseline) to Day 90

Population: 10 patients enrolled - 2 dropped out - 8 completed the study

Augmentation severity rating scale; 0-24, 0 is better, 24 is worst

Outcome measures

Measure	Open-label n=8 Participants open-label single arm study Horizant, 600 mg oral once daily at 5 pm for 360 days. Horizant: Phase1: During phase 1 therapy, Horizant will be added on as an adjunct to all subjects taking part in the study along with stable dose of their current dopaminergic (DA) agent and both medication will be continued for a total period of 90 days from day 0 to day 90. Subjects will be evaluated for three visits (days 0, 30 and 90) during Phase I. Phase 2: At the 90th day follow-up visit, with initiation of phase 2 therapy, all subjects will be tapered off (by 50% reduction in dose each week) of their current dopaminergic agents while maintaining the same dose of Horizant and will be on Horizant monotherapy. All subjects will be evaluated for additional three clinic visits (days 120, 180, 360).
Change in Augmentation Severity From Day 0 to Day 90 Baseline	6.5 score on a scale Interval 5.0 to 13.0
Change in Augmentation Severity From Day 0 to Day 90 90 days	0 score on a scale Interval 0.0 to 2.0

SECONDARY outcome

Timeframe: Day 0 to day 360 (270 days after discontinuing dopaminergic medication)

Population: Only 8 subjects completed the study to its final point

Numeric Scale to assess degree of augmentation; Range 0-24; 0 is better, 24 is worst.

We compared the Augmentation severity scale on day 0 to day 360 (which is 270 days after this decrease of dopaminergic medication)

Outcome measures

Measure	Open-label n=8 Participants open-label single arm study Horizant, 600 mg oral once daily at 5 pm for 360 days. Horizant: Phase1: During phase 1 therapy, Horizant will be added on as an adjunct to all subjects taking part in the study along with stable dose of their current dopaminergic (DA) agent and both medication will be continued for a total period of 90 days from day 0 to day 90. Subjects will be evaluated for three visits (days 0, 30 and 90) during Phase I. Phase 2: At the 90th day follow-up visit, with initiation of phase 2 therapy, all subjects will be tapered off (by 50% reduction in dose each week) of their current dopaminergic agents while maintaining the same dose of Horizant and will be on Horizant monotherapy. All subjects will be evaluated for additional three clinic visits (days 120, 180, 360).
Change in Augmentation Severity Rating Scale Form Day 0 to Day 360 (270 Days After Discontinuation pf Dopaminergic Medication) Day 0 augmentation scale score	6.5 score on a scale Interval 5.0 to 13.0
Change in Augmentation Severity Rating Scale Form Day 0 to Day 360 (270 Days After Discontinuation pf Dopaminergic Medication) Day 360 Augmentation scale score	0 score on a scale Interval 0.0 to 1.0

Adverse Events

Open-label

Serious events: 0 serious events

Other events: 6 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Measure	Open-label n=10 participants at risk open-label single arm study Horizant, 600 mg oral once daily at 5 pm for 360 days. Horizant: Phase1: During phase 1 therapy, Horizant will be added on as an adjunct to all subjects taking part in the study along with stable dose of their current dopaminergic (DA) agent and both medication will be continued for a total period of 90 days from day 0 to day 90. Subjects will be evaluated for three visits (days 0, 30 and 90) during Phase I. Phase 2: At the 90th day follow-up visit, with initiation of phase 2 therapy, all subjects will be tapered off (by 50% reduction in dose each week) of their current dopaminergic agents while maintaining the same dose of Horizant and will be on Horizant monotherapy. All subjects will be evaluated for additional three clinic visits (days 120, 180, 360).
Nervous system disorders Meralgia paraesthetica	10.0% 1/10 • Number of events 1 • 1 year and 7 months Standard adverse event definition used
Cardiac disorders Hypertension	10.0% 1/10 • Number of events 1 • 1 year and 7 months Standard adverse event definition used
Musculoskeletal and connective tissue disorders Plantar fasciitis	10.0% 1/10 • Number of events 1 • 1 year and 7 months Standard adverse event definition used
Musculoskeletal and connective tissue disorders Rheumatoid arthritis - exacerbation	10.0% 1/10 • Number of events 1 • 1 year and 7 months Standard adverse event definition used
Nervous system disorders Sleep apnea	10.0% 1/10 • Number of events 1 • 1 year and 7 months Standard adverse event definition used
Endocrine disorders Calcification on right thyroid gland	10.0% 1/10 • Number of events 1 • 1 year and 7 months Standard adverse event definition used

Additional Information

Pradeep Sahota MD

University of Missouri Columbia

Phone: 573-882-6402

Email: sahotap@missouri.edu

Results disclosure agreements

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