Trial Outcomes & Findings for An Open-Label Study to Evaluate the Long-Term Safety, Tolerability, and Efficacy of OV101 in Individuals With Angelman Syndrome (NCT NCT03882918)

Last Updated: 2025-07-18

Results Overview

Safety assessments related to the primary study objective of evaluating the safety and tolerability of OV101, including serious adverse events (SAEs) and adverse events (AEs) leading to study discontinuation, as assessed by the number of participants who experienced at least one adverse event.

Recruitment status

TERMINATED

Study phase

PHASE3

Target enrollment

141 participants

Primary outcome timeframe

Change from baseline to Week 39

Results posted on

2025-07-18

Participant Flow

Participant milestones

Participant milestones
Measure	OV101 once daily at bedtime (gaboxadol) OV101: Each subject will be titrated to his or her maximal tolerated daily dose, up to a maximum daily dose of 15 mg at bedtime.
Overall Study STARTED	141
Overall Study COMPLETED	1
Overall Study NOT COMPLETED	140

Reasons for withdrawal

Reasons for withdrawal
Measure	OV101 once daily at bedtime (gaboxadol) OV101: Each subject will be titrated to his or her maximal tolerated daily dose, up to a maximum daily dose of 15 mg at bedtime.
Overall Study Study terminated by sponsor	98
Overall Study Protocol Violation	1
Overall Study Other	9
Overall Study Lack of Efficacy	14
Overall Study Adverse Event	13
Overall Study Withdrawal by Subject	5

Baseline Characteristics

An Open-Label Study to Evaluate the Long-Term Safety, Tolerability, and Efficacy of OV101 in Individuals With Angelman Syndrome

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	OV101 n=141 Participants once daily at bedtime (gaboxadol) OV101: Each subject will be titrated to his or her maximal tolerated daily dose, up to a maximum daily dose of 15 mg at bedtime.
Age, Categorical <=18 years	100 Participants n=5 Participants
Age, Categorical Between 18 and 65 years	41 Participants n=5 Participants
Age, Categorical >=65 years	0 Participants n=5 Participants
Sex: Female, Male Female	57 Participants n=5 Participants
Sex: Female, Male Male	84 Participants n=5 Participants
Race (NIH/OMB) American Indian or Alaska Native	1 Participants n=5 Participants
Race (NIH/OMB) Asian	6 Participants n=5 Participants
Race (NIH/OMB) Native Hawaiian or Other Pacific Islander	2 Participants n=5 Participants
Race (NIH/OMB) Black or African American	5 Participants n=5 Participants
Race (NIH/OMB) White	127 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	103 participants n=5 Participants
Region of Enrollment Israel	19 participants n=5 Participants
Region of Enrollment Netherlands	4 participants n=5 Participants
Region of Enrollment Germany	6 participants n=5 Participants
Region of Enrollment Australia	9 participants n=5 Participants

PRIMARY outcome

Timeframe: Change from baseline to Week 39

Population: One participant completed the study; all other participants did not complete the study due to the early termination of the study by the Sponsor.

Outcome measures

Outcome measures
Measure	OV101 n=1 Participants once daily at bedtime (gaboxadol) OV101: Each subject will be titrated to his or her maximal tolerated daily dose, up to a maximum daily dose of 15 mg at bedtime.
Incidence of Participants Experiencing Adverse Events in Active Treatment Group	1 participants

SECONDARY outcome

Timeframe: change from baseline to 12 wks and baseline to early termination of the study at 39 weeks

Population: 132 participants were evaluated using the ABC-I.

The long-term efficacy of OV101 was assessed by changes in irritability using the Aberrant Behavior Checklist - Irritability subscale (ABC-I), part of the broader ABC-Community (ABC-C). The final value reflects change from baseline to early termination at 39 weeks. The ABC-I consists of 15 items measuring behaviors such as aggression, self-injury, temper tantrums, and mood instability. Each item is rated by a caregiver on a 4-point scale: 0 = not at all a problem; 1 = slight problem; 2 = moderately serious; 3 = severe. Scores range from 0 (no symptoms) to 45 (maximum severity). A higher total score indicates greater behavioral disturbance and worse clinical status. The scale provides a standardized means to track symptom changes over time, making it suitable for evaluating treatment efficacy in neurodevelopmental and neuropsychiatric disorders.

Outcome measures

Outcome measures
Measure	OV101 n=132 Participants once daily at bedtime (gaboxadol) OV101: Each subject will be titrated to his or her maximal tolerated daily dose, up to a maximum daily dose of 15 mg at bedtime.
To Evaluate the Long-term Efficacy of OV101 Treatment as Assessed by Changes in Behavior in Study Participants With AS Who Were at Least 4 Years Old. Week 12	-0.7 score on a scale Standard Deviation 1.5
To Evaluate the Long-term Efficacy of OV101 Treatment as Assessed by Changes in Behavior in Study Participants With AS Who Were at Least 4 Years Old. Week 39	-0.5 score on a scale Standard Deviation 1.3

Adverse Events

OV101

Serious events: 18 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	OV101 n=141 participants at risk once daily at bedtime (gaboxadol) OV101: Each subject will be titrated to his or her maximal tolerated daily dose, up to a maximum daily dose of 15 mg at bedtime.
Cardiac disorders Cardiac arrest	0.71% 1/141 • Number of events 1 • from baseline to Week 39, as the trial was terminated early
Gastrointestinal disorders Gastritis	0.71% 1/141 • Number of events 1 • from baseline to Week 39, as the trial was terminated early
Gastrointestinal disorders Hematemesis	0.71% 1/141 • Number of events 1 • from baseline to Week 39, as the trial was terminated early
Infections and infestations Corona virus infection	1.4% 2/141 • Number of events 2 • from baseline to Week 39, as the trial was terminated early
Infections and infestations Device related infection	0.71% 1/141 • Number of events 1 • from baseline to Week 39, as the trial was terminated early
Gastrointestinal disorders Gastroenteritis	0.71% 1/141 • Number of events 1 • from baseline to Week 39, as the trial was terminated early
Infections and infestations Lung infection	0.71% 1/141 • Number of events 1 • from baseline to Week 39, as the trial was terminated early
Respiratory, thoracic and mediastinal disorders Dehydration	0.71% 1/141 • Number of events 1 • from baseline to Week 39, as the trial was terminated early
Nervous system disorders Partial Seizures	1.4% 2/141 • Number of events 2 • from baseline to Week 39, as the trial was terminated early
Nervous system disorders Generalized tonic-clonic seizure	0.71% 1/141 • Number of events 1 • from baseline to Week 39, as the trial was terminated early
Nervous system disorders Headache	0.71% 1/141 • Number of events 1 • from baseline to Week 39, as the trial was terminated early
Nervous system disorders Lethargy	0.71% 1/141 • Number of events 1 • from baseline to Week 39, as the trial was terminated early
Nervous system disorders Seizure Cluster	0.71% 1/141 • Number of events 1 • from baseline to Week 39, as the trial was terminated early
Nervous system disorders Status epilepticus	0.71% 1/141 • Number of events 1 • from baseline to Week 39, as the trial was terminated early
Renal and urinary disorders Acute kidney injury	0.71% 1/141 • Number of events 1 • from baseline to Week 39, as the trial was terminated early
Infections and infestations Atelectasis	0.71% 1/141 • Number of events 1 • from baseline to Week 39, as the trial was terminated early

Other adverse events

Adverse event data not reported

Additional Information

Julia Tsai, PhD

Ovid Therapeutics Inc

Phone: (203) 623-1996

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place