Trial · NCT03030599

A Study of the Efficacy and Safety of JZP-258 in Subjects With Narcolepsy With Cataplexy

NCT03030599, Phase 3, Completed, Jazz Pharmaceuticals; results first posted 2020-11-12

3 sourcestrials-2026-11-12-0.5.0

Cite this record

ConductScience Library. A Study of the Efficacy and Safety of JZP-258 in Subjects With Narcolepsy With Cataplexy. Trials, record NCT03030599. Release trials-2026-11-12-0.5.0, 12 Nov 2026. https://conductscience.org/library/trials/NCT03030599

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Trial

As registered on ClinicalTrials.gov, in the graph's capture of the registry.

Title: A Study of the Efficacy and Safety of JZP-258 in Subjects With Narcolepsy With Cataplexy
NCT number: NCT03030599
Status: Completed
Phases: Phase 3
Enrollment: 201 participants, actual
Lead sponsor: Jazz Pharmaceuticals
Conditions: Narcolepsy With Cataplexy
Interventions: JZP-258, Placebo
First posted: 2017-01-25
Last updated: 2020-11-12
Other registries' IDs: eudract:2016-000426-20
Results first posted: 2020-11-12

Source ClinicalTrials.gov

Registered outcomes6

Each outcome the trial registered, primary first, in ClinicalTrials.gov's words.

List	Outcome	Time frame	Description
Primary	Change in Weekly Number of Cataplexy Attacks	Change from baseline (2 weeks of the Stable Dose Period) to the 2 weeks of the Double Blind Randomized Withdrawal Period (DB RWP)	Participants completed a daily Cataplexy Frequency Diary each night prior to bedtime. Participants were to record the number of cataplexy attacks that they had each day.
Secondary	Change in the Epworth Sleepiness Scale (ESS) Score	From the end of the Stable Dose Period to the end of the Double Blind Randomized Withdrawal Period	This is the key secondary endpoint. The Epworth Sleepiness Scale (ESS) was a self-administered questionnaire with 8 questions. Participants were asked to rate, on a 4-point scale (0-3), their usual chances of dozing off or falling asleep while engaged in eight different activities. Most participants engaged in those activities at least occasionally, although not necessarily every day. The ESS score (the sum of 8 item scores, 0-3) can range from 0 to 24. The higher the ESS score, the higher that participants average sleep propensity in daily life (ASP), or their 'daytime sleepiness'.
Secondary	Number of Participants With Worsening Patient Global Impression of Change (PGIc) for Narcolepsy Overall	At the end of the Double Blind Randomized Withdrawal Period	At the end of the Double Blind Randomized Withdrawal Period (DB RWP), participants rated the change in their condition on a 7-point scale ranging from 1 = "very much improved" to 7 = "very much worse" since the last visit. This endpoint measures the percentage of participants with worsening PGIc scores for narcolepsy overall (defined as scores of Much Worse or Very Much Worse).
Secondary	Number of Participants With Worsening Clinical Global Impression of Change (CGIc) for Narcolepsy Overall	At the end of the Double Blind Randomized Withdrawal Period	At the end of the Double Blind Randomized Withdrawal Period, Investigators rated their impression of any change in the severity of the participant's narcolepsy overall condition since the start of the Double Blind Randomized Withdrawal Period on a 7-point scale ranging from 1 = "very much improved" to 7 = "very much worse". This endpoint measures the percentage of participants with worsening CGIc scores for narcolepsy overall, defined as scores of Much Worse or Very Much Worse.
Secondary	Change in 36-Item Short Form Health Survey Version 2 (SF-36v2) Scores	At the End of the Stable Dose Period to the End of the Double Blind Randomized Withdrawal Period	The SF-36v2 is a multi-purpose, short-form health survey with 36 questions/ items. It yields an 8-scale profile of functional health and well-being scores as well as a psychometrically-based physical and mental overall component summary measures. Two summary scores were derived using the SF-36v2. Physical Component Summary measures dimensions of functional health that are meaningful to respondents, including the impact of health and health-related changes on physical function, pain, and the ability to carry out daily roles. The Mental Component Summary component scale measures the impact of health and health-related changes on well-being, including vitality, social function, and emotional well-being. Participants self-report on items in a summary that have between 2-6 choices per item (e.g. none of the time, some of the time, etc.). Summations of item scores were transformed into a range from 0 to 100; zero= worst HRQL, 100=best HRQL. Higher scores indicate better health status.
Secondary	Change in 5-level EQ-5D (EQ-5D-5L) Crosswalk Index Score and Visual Analog Scale	At the End of the Stable Dose Period to the End of the Double Blind Randomized Withdrawal Period	The EQ-5D-5L is a measure of health outcome that includes a descriptive system consisting of 5 dimensions (mobility, self-care, usual activities, pain/ discomfort, and anxiety/ depression). The EQ-5D-5L includes 5 levels of severity for each of the 5 dimensions of the descriptive system (1= no problems, 2= slight problems, 3= moderate problems, 4= severe problems, and 5= extreme problems) that reflect increasing levels of difficulty. The 5 digit health states for each dimension are converted into a single value per country (0= equivalent to death, 1= equivalent to best imaginable health and values below 0= health states rated worse than death capped at -1), using the EQ-5D-5L crosswalk index value calculator as recommended by EuroQol group. A visual analogue scale (VAS) used within this scale recorded the participants self-rated health on a VAS and the endpoints resulted in a numeric value set ranging from 0 (= worst imaginable health state) up to 100 (= best imaginable health state).

Source ClinicalTrials.gov

Outcomes6

Each outcome the trial posted results for, in ClinicalTrials.gov's words.

Type	Outcome	Time frame	Population	Units	Measured as
PRIMARY	Change in Weekly Number of Cataplexy Attacks	Change from baseline (2 weeks of the Stable Dose Period) to the 2 weeks of the Double Blind Randomized Withdrawal Period (DB RWP)	The efficacy population contains all randomized subjects who received at least one dose of double-blind study drug and had at least one set of post-randomization efficacy data.	attacks	MEDIAN
SECONDARY	Change in the Epworth Sleepiness Scale (ESS) Score	From the end of the Stable Dose Period to the end of the Double Blind Randomized Withdrawal Period	The efficacy population contains all randomized subjects who received at least one dose of double-blind study drug and had at least one set of post-randomization efficacy data.	score on a scale	MEDIAN
SECONDARY	Number of Participants With Worsening Patient Global Impression of Change (PGIc) for Narcolepsy Overall	At the end of the Double Blind Randomized Withdrawal Period	The efficacy population contains all randomized subjects who received at least one dose of double-blind study drug and had at least one set of post-randomization efficacy data.	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Number of Participants With Worsening Clinical Global Impression of Change (CGIc) for Narcolepsy Overall	At the end of the Double Blind Randomized Withdrawal Period	The efficacy population contains all randomized subjects who received at least one dose of double-blind study drug and had at least one set of post-randomization efficacy data.	Participants	COUNT_OF_PARTICIPANTS
SECONDARY	Change in 36-Item Short Form Health Survey Version 2 (SF-36v2) Scores	At the End of the Stable Dose Period to the End of the Double Blind Randomized Withdrawal Period	The efficacy population contains all randomized subjects who received at least one dose of double-blind study drug and had at least one set of post-randomization efficacy data.	score on a scale	MEDIAN
SECONDARY	Change in 5-level EQ-5D (EQ-5D-5L) Crosswalk Index Score and Visual Analog Scale	At the End of the Stable Dose Period to the End of the Double Blind Randomized Withdrawal Period	There were 68 JZP-258 participants included in the Crosswalk Index, and 69 JZP-258 participants in the VAS Score. The efficacy population contains all randomized subjects who received at least one dose of double-blind study drug and had at least one set of post-randomization efficacy data.	score on a scale	MEDIAN

Source ClinicalTrials.gov

Results by group16

Each measurement the trial posted, group by group, in the words and numbers it posted.

Outcome	Group	Category	Value	Spread	Units
Change in Weekly Number of Cataplexy Attacks	JZP-258		0.00	Inter-Quartile Range -0.49 to 1.75	attacks
Change in Weekly Number of Cataplexy Attacks	Placebo		2.35	Inter-Quartile Range 0.00 to 11.61	attacks
Change in the Epworth Sleepiness Scale (ESS) Score	JZP-258		0.00	Inter-Quartile Range -1.0 to 1.0	score on a scale
Change in the Epworth Sleepiness Scale (ESS) Score	Placebo		2.0	Inter-Quartile Range 0.00 to 5.0	score on a scale
Number of Participants With Worsening Patient Global Impression of Change (PGIc) for Narcolepsy Overall	JZP-258		3		Participants
Number of Participants With Worsening Patient Global Impression of Change (PGIc) for Narcolepsy Overall	Placebo		29		Participants
Number of Participants With Worsening Clinical Global Impression of Change (CGIc) for Narcolepsy Overall	JZP-258		4		Participants
Number of Participants With Worsening Clinical Global Impression of Change (CGIc) for Narcolepsy Overall	Placebo		39		Participants
Change in 36-Item Short Form Health Survey Version 2 (SF-36v2) Scores	JZP-258	Physical Component Summary	-0.03	Inter-Quartile Range -2.07 to 2.41	score on a scale
Change in 36-Item Short Form Health Survey Version 2 (SF-36v2) Scores	Placebo	Physical Component Summary	-1.92	Inter-Quartile Range -3.46 to 1.73	score on a scale

1 to 10 of 16Source ClinicalTrials.gov

See all 16 results by group

Participant flow36

How many started, completed or left each group, period by period.

Period	Milestone	Group	Participants
Open Label Treatment and Titration	STARTED	Open-label JZP-258	201
Open Label Treatment and Titration	STARTED	JZP-258	0
Open Label Treatment and Titration	STARTED	Placebo	0
Open Label Treatment and Titration	COMPLETED	Open-label JZP-258	155
Open Label Treatment and Titration	COMPLETED	JZP-258	0
Open Label Treatment and Titration	COMPLETED	Placebo	0
Open Label Treatment and Titration	NOT COMPLETED	Open-label JZP-258	46
Open Label Treatment and Titration	NOT COMPLETED	JZP-258	0
Open Label Treatment and Titration	NOT COMPLETED	Placebo	0
Stable Dose	STARTED	Open-label JZP-258	149

1 to 10 of 36Source ClinicalTrials.gov

See all 36 participant flow

Adverse events38

Each adverse event the trial posted, group by group: the participants affected out of those at risk.

Type	Event	Organ system	Group	Affected	At risk
other	Cataplexy	Nervous system disorders	JZP-258	21	201
other	Cataplexy	Nervous system disorders	Placebo	5	65
other	Dizziness	Nervous system disorders	JZP-258	23	201
other	Dizziness	Nervous system disorders	Placebo	0	65
other	Headache	Nervous system disorders	JZP-258	45	201
other	Headache	Nervous system disorders	Placebo	1	65
other	Somnolence	Nervous system disorders	JZP-258	5	201
other	Somnolence	Nervous system disorders	Placebo	6	65
other	Diarrhoea	Gastrointestinal disorders	JZP-258	13	201
other	Diarrhoea	Gastrointestinal disorders	Placebo	0	65

1 to 10 of 38Source ClinicalTrials.gov

See all 38 adverse events

Adverse event totals6

The totals the trial posted for each group.

Total	Group	Affected	At risk
Total, all-cause mortality	JZP-258	0	201
Total, all-cause mortality	Placebo	0	65
Total, other adverse events	JZP-258	108	201
Total, other adverse events	Placebo	12	65
Total, serious adverse events	JZP-258	5	201
Total, serious adverse events	Placebo	2	65

Source ClinicalTrials.gov

Papers3

The papers the trial lists on ClinicalTrials.gov.

PMID	Listed as	Source
33184650	DERIVED	PubMed
35635687	DERIVED	PubMed
36947322	DERIVED	PubMed

Grants0

The grants NIH RePORTER links to the trial, newest funded first: NIH's, and some of AHRQ's, CDC's, FDA's and VA's. Each shows its title, principal investigators, organization and funder in its newest year.

None in this release.

Trial comparisons4

Comparisons of the trial's two groups, calculated by ConductScience from the counts it posted.

Comparison	Source
JZP-258 vs Placebo: Number of Participants With Worsening Clinical Global Impression of Change (CGIc) for Narcolepsy Overall	Trial comparisons
JZP-258 vs Placebo: deaths from any cause	Trial comparisons
JZP-258 vs Placebo: Number of Participants With Worsening Patient Global Impression of Change (PGIc) for Narcolepsy Overall	Trial comparisons
JZP-258 vs Placebo: serious adverse events	Trial comparisons

Tests0

The ConductCognition tests this trial's registered outcomes name, as ScienceGraph matched them in trial-tests-2026-11-12-0.2.1.

None in this release.

Data dates

The day each source was copied for this release.

ClinicalTrials.gov: 2026-11-12; ClinicalTrials.gov
Results, from AACT: 2026-03-23; AACT
NIH grant links: 2026-11-13; NIH RePORTER

Sources 3

ClinicalTrials.gov's posted results, through CTTI's AACTFreely available. Acknowledgement requested
ClinicalTrials.govNo license stated
NIH RePORTER's clinical studies and project filesPublic domain

Each source's terms

ClinicalTrials.gov's posted results, through CTTI's AACTClinicalTrials.gov data via Aggregate Analysis of ClinicalTrials.gov (AACT), CTTI. CTTI makes its materials freely available and requests acknowledgement. https://aact.ctti-clinicaltrials.org/documentation/299
ClinicalTrials.govnone stated
NIH RePORTER's clinical studies and project filesPublic domain (NIH RePORTER)

ClinicalTrials.gov's data carry an international copyright outside the United States: https://clinicaltrials.gov/about-site/terms-conditions.

For software

Read this trial from software.

The record and each of its lists are JSON, twenty rows a page. No key.

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API reference For AI assistants