Efficacy, Safety, Tolerability, and Pharmacokinetics of NBI-827104 in Pediatric Subjects With Epileptic Encephalopathy With Continuous Spike-and-Wave During Sleep

Phase 2 Multicenter, Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study to Assess the Efficacy, Safety, Tolerability, and Pharmacokinetics of NBI-827104 in Pediatric Subjects With Epileptic Encephalopathy With Continuous Spike-and-Wave During Sleep

This is a phase 2, double-blind study to assess the efficacy, safety, tolerability, and pharmacokinetics of NBI-827104 when administered once daily for 13 weeks in pediatric subjects with Epileptic Encephalopathy with Continuous Spike-and-Wave During Sleep (EECSWS).

Study Overview

• Status: Completed
• Conditions: Epileptic Encephalopathy; Continuous Spike and Wave During Sleep
• Intervention / Treatment: Drug: NBI-827104; Drug: Placebo

• Study Type: Interventional
• Enrollment (Actual): 24
• Phase: Phase 2

Contacts and Locations

Study Locations

• Canada
  • Alberta
    • Calgary, Alberta, Canada, T3B 6A8
      • Neurocrine Clinical Site
• Denmark
  • Dianalund, Denmark, 4293
    • Neurocrine Clinical Site
• Spain
  • Barcelona, Spain, 08950
    • Neurocrine Clinical Site
  • Madrid, Spain, 28034
    • Neurocrine Clinical Site
• Switzerland
  • Basel, Switzerland, 4031
    • Neurocrine Clinical Site
  • Zurich, Switzerland, 8032
    • Neurocrine Clinical Site
• United Kingdom
  • London, United Kingdom, WC1N 3JH
    • Neurocrine Clinical Site
• United States
  • California
    • Orange, California, United States, 92868
      • Neurocrine Clinical Site
  • Colorado
    • Aurora, Colorado, United States, 80045
      • Neurocrine Clinical Site
  • District of Columbia
    • Washington D.C., District of Columbia, United States, 20010
      • Neurocrine Clinical Site
  • Florida
    • Miami, Florida, United States, 33155
      • Neurocrine Clinical Site
  • Minnesota
    • Rochester, Minnesota, United States, 55905
      • Neurocrine Clinical Site
  • North Carolina
    • Durham, North Carolina, United States, 27710
      • Neurocrine Clinical Site
  • Ohio
    • Cleveland, Ohio, United States, 44195
      • Neurocrine Clinical Site
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19104
      • Neurocrine Clinical Site

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 6 months to 8 years (Child)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Signed informed consent by the parent(s) or legal representative(s) and, if applicable, assent from developmentally capable pediatric subjects.
2. Diagnosis of EECSWS.
3. Have diagnosis of EECSWS confirmed by the Diagnosis Confirmation Panel (DCP).
4. Stable dosage and stable time of intake of at least 1 and up to 3 antiseizure medications (ASMs) excluding systemic corticosteroids and intravenous immunoglobulin (IVIG), from 4 weeks prior to screening and anticipated to be stable from screening until end of study (EOS). Vagal nerve stimulator (VNS) and ketogenic diet are not counted as ASMs.
5. Treatment other than ASMs (excluding systemic corticosteroids and IVIG) must be at a stable dosage from 2 weeks prior to screening and anticipated to be stable from screening until EOS.

Exclusion Criteria:

1. Lennox-Gastaut syndrome, Doose syndrome (epilepsy with myoclonic-atonic seizures), or Dravet syndrome.
2. Presence of a relevant psychiatric disease interfering with cognitive or behavioral functioning (eg, depression, schizophrenia, autism spectrum disorder) unless associated with the EECSWS diagnosis as assessed by the investigator.
3. Presence of relevant neurological disorders other than EECSWS and its underlying conditions as judged by the investigator. Symptomatic conditions underlying EECSWS (eg, neonatal strokes) have to be stable for at least 1 year prior to screening.
4. Body weight <10 kg at randomization.
5. Clinically relevant findings in systolic blood pressure (SBP), diastolic blood pressure (DBP), or pulse rate at screening or Day 1 as determined by the investigator.
6. Have an average triplicate ECG corrected QT interval using Fridericia's formula (QTcF) >450 msec or presence of any significant cardiac abnormality at screening.
7. Clinically relevant findings in clinical laboratory tests (hematology, clinical chemistry including thyroid function parameters, and urinalysis) at screening as determined by the investigator.
8. Have aspartate aminotransferase (AST), alanine aminotransferase (ALT), or gamma-glutamyl transferase (GGT) levels >2 × the upper limit of normal (ULN) at screening.
9. Have mild to severe renal impairment as determined by the investigator.
10. Have taken cannabinoids, excluding Epidiolex®/Epidyolex®, within 30 days of screening.
11. Pulse therapy such as systemic corticosteroids and IVIG are prohibited for at least 8 weeks prior to screening.
12. Planned surgical intervention related to structural abnormalities of the brain from screening through the duration of the study.
13. Have received any other investigational drug within 30 days or 5 half-lives (if known), whichever is longer, of Day 1 or plan to use an investigational drug (other than the study treatment) during the study.
14. Any circumstances or conditions, which, in the opinion of the investigator, may affect full participation in the study or compliance with the protocol.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: NBI-827104; NBI-827104 administered orally for 13 weeks.	Drug: NBI-827104; Triple T-type calcium channel blocker.
Placebo Comparator: Placebo; Placebo administered orally for 13 weeks.	Drug: Placebo; Non-active dosage form.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ratio of Spike-Wave Index (SWI) During First Hour of Nonrapid Eye Movement (NREM) Sleep at Week 6	The ratio of SWI at the end of Week 6 to baseline during the first hour (60 minutes) of NREM sleep based on centralized video-electroencephalograph (EEG) reading using a log base 10 scale. Baseline was defined as the last value measured prior to intake of study treatment on Day 1. SWI was defined as the percentage of seconds with ≥1 spike-wave complex(es) during defined periods of overnight NREM sleep.	Baseline to Week 6

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ratio of SWI During First Hour of NREM Sleep at Week 12	The ratio of SWI at the end of Week 12 to baseline during the first hour (60 minutes) of NREM sleep based on centralized video-EEG reading using a log base 10 scale. Baseline was defined as the last value measured prior to intake of study treatment on Day 1. SWI was defined as the percentage of seconds with ≥1 spike-wave complex(es) during defined periods of overnight NREM sleep.	Baseline to Week 12
Number of Participants Considered as Responders as Assessed by the Caregiver Global Impression of Change (CaGI-C) Score	The CaGI-C is a 7-point scale that rates the caregiver's assessment of the overall improvement in the participants symptoms since the initiation of study treatment, ranging from 1 (very much improved) to 7 (very much worse). A responder was defined as a participant with a score of 1 (very much improved) or 2 (much improved).	Week 6 and Week 12
Number of Participants Considered as Responders as Assessed by the Clinician Global Impression of Change (CGI-C) Score	The CGI-C is a 7-point scale that rates the clinician's assessment of overall improvement in the participant's symptoms since the initiation of study treatment, ranging from 1 (very much improved) to 7 (very much worse). A responder was defined as a participant with a score of 1 (very much improved) or 2 (much improved).	Week 6 and Week 12
Number of Participants Considered as Responders as Assessed by the Clinical Global Impression of Severity (CGI-S) Scores	The CGI-S is a 7-point scale that rates the clinician's assessment of overall symptom severity, ranging from 1 (normal, not at all ill) to 7 (among the most extremely ill patients). A responder was defined as a participant with at least 1-point improvement in the CGI-S score from baseline.	Weeks 6 and 12

Collaborators and Investigators

• Sponsor: Neurocrine Biosciences
• Investigators: Study Director: Clinical Development Lead, Neurocrine Biosciences

Publications and helpful links

Helpful Links

• Study Website - Stillwater Study

Study record dates

Study Major Dates

• Study Start (Actual): April 26, 2021
• Primary Completion (Actual): August 8, 2022
• Study Completion (Actual): October 11, 2022

Study Registration Dates

• First Submitted: November 6, 2020
• First Submitted That Met QC Criteria: November 6, 2020
• First Posted (Actual): November 12, 2020

Study Record Updates

• Last Update Posted (Estimated): September 5, 2025
• Last Update Submitted That Met QC Criteria: September 3, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Central Nervous System Diseases; Nervous System Diseases; Epilepsy; Brain Diseases; Substandard Drugs; Pharmaceutical Preparations; Counterfeit Drugs
• Other Study ID Numbers: NBI-827104-CSWS2010; 2020-003141-11 (EudraCT Number)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No