A Phase 2 interventional study of SUVN-G3031 and Placebo in Narcolepsy, sponsored by Suven Life Sciences Limited. Completed at 41 sites in 2 countries. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2025-01-13.
Sponsored by Suven Life Sciences Limited · Phase 2, Interventional, and Treatment
This study is of an investigational drug called SUVN-G3031 (Samelisant) as a possible treatment for narcolepsy with cataplexy or narcolepsy without cataplexy. The main purpose of this study is to learn how well the study drug works and how safe the study drug is compared to placebo.
This is a Phase 2, double-blind, placebo-controlled, parallel-group, multicenter study to evaluate the safety, tolerability, pharmacokinetics (PK), and efficacy of SUVN-G3031 compared to placebo in participants with narcolepsy with and without cataplexy. Participants will be randomized at a ratio of 1:1:1 to 2 mg SUVN-G3031, 4 mg SUVN-G3031, or placebo. Each participant will receive study drug once daily, in a tablet formulation, for 14 days.
31 studies on the registry are indexed under Cataplexy; 5 are open to participants now.
This study's enrollment of 190 is above the median of 117 across 27 interventional studies indexed under Cataplexy.
Browse Cataplexy studies →Suven Life Sciences Limited is the lead sponsor of 15 studies on the registry; 1 is open to participants now.
Of its 7 completed or terminated interventional studies of FDA-regulated products, 2 (29%) have results posted.
Compared within Cataplexy, this study's primary condition as ClinicalTrials.gg classifies it; the registry's first condition term is Narcolepsy. The counts are of registry records indexed under each term, refreshed daily. How we classify →
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Childbearing potential
Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).
Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Orally taken once daily for 14 days
Drug: SUVN-G3031
Orally taken once daily for 14 days
Drug: SUVN-G3031
Orally taken once daily for 14 days
Drug: Placebo
SUVN-G3031 Tablets
Also known as: Samelisant
Placebo Tablets
Epworth Sleepiness Scale
The Epworth Sleepiness Scale (ESS) is a patient-reported questionnaire consisting of 8 questions. Each of the items are rated on a 4-point scale (0-3), based on the usual chances of dozing off or falling asleep while engaged in eight different activities. The total ESS score (the sum of 8 item scores, 0-3) can range from 0 to 24. Higher values represent a worse outcome.
Time frame: Change from baseline in the mean total ESS score at Day 14
Clinical Global Impression of Severity
The Clinical Global Impressions of Severity (CGI-S) scale is used to rate the severity of the patient's illness by clinician, on a 7-point scale with score ranging from 1 - 7. Higher values represent a worse outcome.
Time frame: Change from baseline in the mean CGI-S score at Day 14
Maintenance of Wakefulness Test
Maintenance of Wakefulness Test (MWT) is an objective test of sleepiness that evaluates a person's ability to remain awake under soporific conditions for a defined period of time. In the MWT, time from start of the test to the time point of falling asleep will be measured, the total score can range from 0 - 30 minutes. Higher values represent a better outcome.
Time frame: Change from baseline in the mean MWT score at Day 14
Patient Global Impression of Change
The PGI-C is based on a 7-point scale, where at each time point the patient will rate the change from baseline using the following query: "Since the start of the study, my overall status is: 1 = very much better; 2 = much better; 3 = a little better; 4 = no change; 5 = a little worse; 6 = much worse; 7 = very much worse." The PGI-C assessment will be based on change observed from baseline related to excessive daytime sleepiness rather than on the totality of the disease.
Time frame: Analysis of Patient Global Impression of Change (PGI-C) at Day 14
Clinical Global Impression of Change
The CGI-C is based on a 7-point scale, where at each time point the physician will rate the change from baseline using the following query: "Compared to the patient's condition at admission to the project \[prior to medication initiation\], this patient's condition is: 1 = very much improved since the initiation of treatment; 2 = much improved; 3 = minimally improved; 4 = no change from baseline (the initiation of treatment); 5 = minimally worse; 6 = much worse; 7 = very much worse since the initiation of treatment." The CGI-C assessment will be based on change observed from baseline related to excessive daytime sleepiness rather than on the totality of the disease.
Time frame: Analysis of Clinical Global Impression of Change (CGI-C) at Day 14
| Milestone | SUVN-G3031 2mg | SUVN-G3031 4mg | Placebo |
|---|---|---|---|
| Started | 63 | 64 | 63 |
| Safety population | 63 | 63 | 62 |
| Intent-to-treat (itt) population | 54 | 53 | 57 |
| Completed | 51 | 50 | 53 |
| Not completed | 12 | 14 | 10 |
| Withdrew: Adverse event | 4 | 6 | 0 |
| Withdrew: Withdrawal by subject | 3 | 1 | 1 |
| Withdrew: Physician decision | 2 | 0 | 0 |
| Withdrew: Protocol violation | 0 | 2 | 3 |
| Withdrew: Intercurrent illness and others | 3 | 5 | 6 |
The Epworth Sleepiness Scale (ESS) is a patient-reported questionnaire consisting of 8 questions. Each of the items are rated on a 4-point scale (0-3), based on the usual chances of dozing off or falling asleep while engaged in eight different activities. The total ESS score (the sum of 8 item scores, 0-3) can range from 0 to 24. Higher values represent a worse outcome.
| score on a scale | SUVN-G3031 2mg | SUVN-G3031 4mg | Placebo |
|---|---|---|---|
| Epworth Sleepiness Scale | -5.1 ± 5.00 | -5.6 ± 5.46 | -3.3 ± 4.61 |
The Clinical Global Impressions of Severity (CGI-S) scale is used to rate the severity of the patient's illness by clinician, on a 7-point scale with score ranging from 1 - 7. Higher values represent a worse outcome.
| score on a scale | SUVN-G3031 2mg | SUVN-G3031 4mg | Placebo |
|---|---|---|---|
| Clinical Global Impression of Severity | -1.2 ± 1.24 | -1.4 ± 1.19 | -0.8 ± 1.17 |
Maintenance of Wakefulness Test (MWT) is an objective test of sleepiness that evaluates a person's ability to remain awake under soporific conditions for a defined period of time. In the MWT, time from start of the test to the time point of falling asleep will be measured, the total score can range from 0 - 30 minutes. Higher values represent a better outcome.
| minutes | SUVN-G3031 2mg | SUVN-G3031 4mg | Placebo |
|---|---|---|---|
| Maintenance of Wakefulness Test | 2.07 ± 4.68 | 4.25 ± 6.52 | 2.73 ± 7.00 |
The PGI-C is based on a 7-point scale, where at each time point the patient will rate the change from baseline using the following query: "Since the start of the study, my overall status is: 1 = very much better; 2 = much better; 3 = a little better; 4 = no change; 5 = a little worse; 6 = much worse; 7 = very much worse." The PGI-C assessment will be based on change observed from baseline related to excessive daytime sleepiness rather than on the totality of the disease.
| score on a scale | SUVN-G3031 2mg | SUVN-G3031 4mg | Placebo |
|---|---|---|---|
| Patient Global Impression of Change | 3.2 ± 1.16 | 2.8 ± 1.10 | 3.7 ± 1.12 |
The CGI-C is based on a 7-point scale, where at each time point the physician will rate the change from baseline using the following query: "Compared to the patient's condition at admission to the project \[prior to medication initiation\], this patient's condition is: 1 = very much improved since the initiation of treatment; 2 = much improved; 3 = minimally improved; 4 = no change from baseline (the initiation of treatment); 5 = minimally worse; 6 = much worse; 7 = very much worse since the initiation of treatment." The CGI-C assessment will be based on change observed from baseline related to excessive daytime sleepiness rather than on the totality of the disease.
| score on a scale | SUVN-G3031 2mg | SUVN-G3031 4mg | Placebo |
|---|---|---|---|
| Clinical Global Impression of Change | 2.8 ± 1.01 | 2.6 ± 0.92 | 3.5 ± 0.91 |
Collected over From screening to Day 21. Non-serious events are listed at a 5% frequency threshold.
| Group | Deaths | Serious | Other |
|---|---|---|---|
| SUVN-G3031 2mg | 0/63 (0%) | 0/63 (0%) | 17/63 (27%) |
| SUVN-G3031 4mg | 0/63 (0%) | 0/63 (0%) | 34/63 (54%) |
| Placebo | 0/62 (0%) | 0/62 (0%) | 5/62 (8.1%) |
| Event | SUVN-G3031 2mg | SUVN-G3031 4mg | Placebo |
|---|---|---|---|
| InsomniaPsychiatric disorders | 6/63 | 11/63 | 2/62 |
| NauseaGastrointestinal disorders | 5/63 | 11/63 | 2/62 |
| Hot flushVascular disorders | 3/63 | 7/63 | 1/62 |
| Abnormal dreamsPsychiatric disorders | 3/63 | 5/63 | 0/62 |
A total of 188 (98.9%) patients who were randomized to specific treatment sequence were included in the safety population and this population is considered for baseline analysis.
| Age, Continuous(years) | SUVN-G3031 2mg | SUVN-G3031 4mg | Placebo | Total |
|---|---|---|---|---|
| Mean | 29.8 ± 8.59 | 34.0 ± 10.0 | 33.6 ± 10.02 | 32.5 ± 9.70 |
| Sex: Female, Male(Participants) | SUVN-G3031 2mg | SUVN-G3031 4mg | Placebo | Total |
|---|---|---|---|---|
| Female | 45 | 44 | 44 | 133 |
| Male | 18 | 19 | 18 | 55 |
| Ethnicity (NIH/OMB)(Participants) | SUVN-G3031 2mg | SUVN-G3031 4mg | Placebo | Total |
|---|---|---|---|---|
| Hispanic or Latino | 4 | 11 | 6 | 21 |
| Not Hispanic or Latino | 59 | 52 | 56 | 167 |
| Unknown or Not Reported | 0 | 0 | 0 | 0 |
| Race (NIH/OMB)(Participants) | SUVN-G3031 2mg | SUVN-G3031 4mg | Placebo | Total |
|---|---|---|---|---|
| American Indian or Alaska Native | 0 | 1 | 1 | 2 |
| Asian | 3 | 7 | 2 | 12 |
| Native Hawaiian or Other Pacific Islander | 0 | 0 | 1 | 1 |
| Black or African American | 13 | 16 | 14 | 43 |
| White | 47 | 38 | 43 | 128 |
| More than one race | 0 | 0 | 0 | 0 |
| Unknown or Not Reported | 0 | 1 | 1 | 2 |
| Region of Enrollment(participants) | SUVN-G3031 2mg | SUVN-G3031 4mg | Placebo | Total |
|---|---|---|---|---|
| Canada | 6 | 3 | 4 | 13 |
| United States | 57 | 60 | 58 | 175 |
| Epworth Sleepiness Scale (ESS)(units on a scale) | SUVN-G3031 2mg | SUVN-G3031 4mg | Placebo | Total |
|---|---|---|---|---|
| Mean | 17.3 ± 2.76 | 17.5 ± 2.84 | 17.1 ± 3.03 | 17.3 ± 2.86 |
| Clinical Global Impression of Severity (CGI-S)(units on a scale) | SUVN-G3031 2mg | SUVN-G3031 4mg | Placebo | Total |
|---|---|---|---|---|
| Mean | 4.7 ± 0.80 | 4.8 ± 0.83 | 4.7 ± 0.87 | 4.8 ± 0.83 |
| Maintenance of Wakefulness Test (MWT)(minutes) | SUVN-G3031 2mg | SUVN-G3031 4mg | Placebo | Total |
|---|---|---|---|---|
| Mean | 5.166 ± 4.466 | 6.141 ± 4.073 | 6.242 ± 4.158 | 5.846 ± 4.243 |
1 further baseline measures are reported on the registry.
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: No
Ran from Sep 2019 to primary completion in Jun 2023, 44 months.
Results were first posted in Jan 2025, 1 year 7 months after primary completion.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Jan 2025. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Samelisant
Suven Life Sciences Limited