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Narcolepsy Type 1 (NT1)Phase 3NCT07363720

A Trial of TAK-861 for the Treatment of Narcolepsy With Cataplexy

A Phase 3 study testing TAK-861 in people with Narcolepsy Type 1 (NT1) and Narcolepsy With Cataplexy, run by Takeda at 25 sites in 7 countries.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial summary

The main aim of this study is to assess how effective TAK-861 is for treating narcolepsy type 1 and if this effect is maintained over time. Participants will take TAK-861 for a few months and if they meet certain criteria, they will be randomly assigned (by chance, like flipping a coin) to continue taking TAK-861 or… Read more about this study

Who is it for?
Ages 16 to 70 years
What is being tested?
TAK-861
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
98 participants
Where
25 sitesin 7 countries
Study dates
29 Jan 2026to 17 Dec 2026
Phase
Phase 3
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 16 to 70 years
  • All sexes
  • No healthy volunteers
  • Child, Adult, Older adult

Who may be able to join

  • The participant has a body mass index (BMI) within the range 18 to 40 kilograms per square meter (kg/m^2).
  • The participant has an International Classification of Sleep Disorders, Third Edition (ICSD-3) or International Classification of Sleep Disorders, Third Edition, Text Revision (ICSD-3-TR) diagnosis of NT1.
  • The participant is positive for the human leukocyte antigen (HLA) genotype Major Histocompatibility Complex, Class II, DQ Beta 1 (HLA-DQB1*06:02) or results from radioimmunoassay indicate the participant's CSF OX/hypocretin-1 concentration is ≤110 pg/mL (or less than one-third of the mean values obtained in normal participants within the same standardized assay).

Who cannot join

  • The participant has a current medical disorder, other than narcolepsy with cataplexy, associated with EDS.
  • The participant a) has a history of myocardial infarction, b) has a history of clinically significant hepatic disease, thyroid disease, coronary artery disease, cardiac rhythm abnormality or heart failure, or c) has any medical condition (such as unstable cardiovascular, pulmonary, renal or gastrointestinal disease.
  • The participant has current or recent (within 6 months) gastrointestinal disease that is expected to influence the absorption of drugs.
  • The participant has a history of cancer in the past 5 years.
  • The participant has a clinically significant history of head injury or head trauma.
  • The participant has a history of epilepsy, seizure, or convulsion (except for a single febrile seizure in childhood).
  • The participant has a history of cerebral ischemia, transient ischemic attack (less than 5 years from screening), intracranial aneurysm, or arteriovenous malformation.

Trial locations and contacts

25 sites in 7 countries.

25 sites in 7 countries

United States11 sites

  • Takeda Site 21

    Austin, Texas, 78731

  • Takeda Site 19

    Brandon, Florida, 33511

  • Takeda Site 16

    Cincinnati, Ohio, 45245

  • Takeda Site 18

    Cleveland, Ohio, 44195

  • Takeda Site 17

    Columbia, South Carolina, 29201

  • Takeda Site 24

    Durham, North Carolina, 27710-4000

  • Takeda Site 22

    Miami, Florida, 33155

  • Takeda Site 20

    Middletown, New Jersey, 07748

  • Takeda Site 15

    Redwood City, California, 94063

  • Takeda Site 23

    Southfield, Michigan, 48075

  • Takeda Site 25

    Winston-Salem, North Carolina, 27103

Other trials in United States

Spain4 sites

  • Takeda Site 11

    Alzira, Valencia, 46600

  • Takeda Site 10

    Barcelona, 08036

  • Takeda Site 9

    Madrid, 28043

  • Takeda Site 12

    Vitoria-Gasteiz, Alava, 01004

Other trials in Spain

France3 sites

  • Takeda Site 1

    Montpellier, 34295

  • Takeda Site 2

    Paris, 75013

  • Takeda Site 3

    Toulouse, 31059

Other trials in France

Germany2 sites

  • Takeda Site 5

    Berlin, 10117

  • Takeda Site 4

    Schwerin, Mecklenburg-Vorpommern, 19053

Other trials in Germany

Italy2 sites

  • Takeda Site 6

    Bologna, Emilia-Romagna, 40139

  • Takeda Site 7

    Rome, Lazio, 00133

Other trials in Italy

Switzerland2 sites

  • Takeda Site 13

    Barmelweid, Canton of Aargau, 5017

  • Takeda Site 14

    Bern, 3010

Other trials in Switzerland

Netherlands1 site

  • Takeda Site 8

    Heemstede, 2103 SW

Other trials in Netherlands

About this study

Official title: A Double-blind, Placebo-Controlled, Randomized Withdrawal Trial to Evaluate the Efficacy and Safety of TAK-861 for the Treatment of Narcolepsy With Cataplexy (Narcolepsy Type 1)

The main aim of this study is to assess how effective TAK-861 is for treating narcolepsy type 1 and if this effect is maintained over time. Participants will take TAK-861 for a few months and if they meet certain criteria, they will be randomly assigned (by chance, like flipping a coin) to continue taking TAK-861 or take placebo (fake medicine) for up to 4 weeks to see if their narcolepsy symptoms return.

Read the detailed description

The drug being tested in this study is called TAK-861. This study will look at how effective TAK-861 is for the treatment of narcolepsy type 1 and how well this effect is maintained over time. This study also evaluates how safe TAK-861 is and what adverse events may be associated with taking the drug and stopping the drug in participants with NT1.

The study will enroll approximately 88 participants. All participants will take TAK-861 during the open-label (OL) treatment period. Participants who meet certain criteria at the end of the OL Treatment Period will be randomized to one of two treatment groups for the up to 4-week double-blind randomized withdrawal (RW) Period. Participants will be randomized to one of the following treatment groups during the Double-blind RW Period:

  1. TAK-861 (same dose participant was taking at the end of the OL Treatment Period)
  2. Placebo

The randomized withdrawal period may last up to 4 weeks. Participants whose NT1 symptoms get worse during the RW period and whose Epworth Sleepiness Scale score rises above a certain score will stop the treatment and be invited to continue in a separate long term extension study. Participants who choose not to take part in the extension study will be followed-up for 4 weeks after their last dose of study drug. This multi-center trial will be conducted globally.

Being tested
TAK-861, Placebo
Keywords
Drug Therapy
Medical subject headings
Narcolepsy

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • TAK-861Drug

    TAK-861 tablets

  • PlaceboDrug

    TAK-861-matching placebo tablets

Study groups in NCT07363720
Study groupRoleWhat they receive
Double-blind RW Period: TAK-861ExperimentalParticipants on stable TAK 861 dose will receive the same dose of TAK-861 they were taking at the end of the OL treatment period, for up to 4 weeks in the double-blind RW period.
Receives: Drug: TAK-861
Double-blind RW Period: PlaceboPlacebo comparatorParticipants will receive TAK-861 matching-placebo, for up to 4 weeks in the double-blind RW period.
Receives: Drug: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Time to Loss of Response in the Epworth Sleepiness Scale (ESS) Score During the Up to 4-Week RW Period

    The ESS provides individuals with 8 different situations of daily life and asks them how likely they are to fall asleep in those situations (scored 0 to 3) and to try to imagine their likelihood of dozing even if they have not actually been in the identical situation; the scores are summed to give an overall score of 0 to 24. Higher scores indicate stronger subjective daytime sleepiness, and scores below 10 are considered to be within normal range.

    Measured: Up to 4-week RW period

Secondary outcomes (8)

  1. Change From the End of the OL Treatment Period to Week 2 of the RW Period on the Maintenance of Wakefulness Test (MWT)

    The MWT evaluates a person's ability to remain awake under soporific conditions for a defined period of time. Because there is no biological measure of wakefulness, wakefulness is measured indirectly by the inability or delayed tendency to fall asleep. This tendency to fall asleep is measured via electroencephalography (EEG)-derived sleep latency in the MWT. The MWT consists of four 40-minute sessions. Sleep latency in each wake trial will be recorded. Participants will be required to stay awake in between the 4 sessions.

    Measured: From the end of the OL treatment period (Week 16) to Week 2 of the RW period (Week 18)

  2. Weekly Cataplexy Rate (WCR) at Week 2 of the RW Period

    Measured: Week 2 of the RW period

  3. Change from the End of the OL Treatment Period to Week 2 of the RW Period in Mean Number of Lapses on the Psychomotor Vigilance Test (PVT)

    The PVT is a simple reaction performance task with a duration of 10 minutes that aims to measure sustained attention.

    Measured: From the end of the OL treatment period (Week 16) to Week 2 of the RW period (Week 18)

  4. Number of Participants Reporting Much or Very Much Worse in Patient Global Impression of Change (PGI-C) Score at Week 2 of the RW Period

    The PGI-C is a participant self-rated scale to assess improvement in daytime sleepiness and overall narcolepsy symptoms. It measures change due to treatment relative to baseline on a 7-point scale ranging from a score of 1 ("very much improved") to score of 7 ("very much worse").

    Measured: Week 2 of the RW period

  5. Change from the End of the OL Treatment Period to Week 2 of the RW Period in Narcolepsy Severity Scale for Clinical Trials (NSS-CT) Total Score

    The NSS-CT is a 15-item self-administered questionnaire assesses the severity and consequences of the 5 major narcolepsy symptoms such as daytime sleepiness, cataplexy, hallucinations, sleep paralysis, and disturbed night-time sleep (DNS) with a total score range of 0 to 57 (sum of 6 items that assess symptoms severity are rated using a six-point Likert scale [0-5] and 9 items that describe the symptom effect on daily life are rated using a four-point Likert scale [0-3]. Higher total scores mean a worse outcome.

    Measured: From the end of the OL treatment period (Week 16) to Week 2 of the RW period (Week 18)

  6. Change from the End of the OL Treatment Period to Week 2 of the RW Period in Functional Impacts of Narcolepsy Instrument (FINI) Domain Scores

    The FINI measures the functional impacts of narcolepsy across 6 domains. Each domain is scored from 0 to 4, where 0 indicates the best health and 4 the worst.

    Measured: From the end of the OL treatment period (Week 16) to Week 2 of the RW period (Week 18)

  7. Change from the End of the OL Treatment Period to Week 2 of the RW Period in Number of Correct Responses on the International Digit Symbol Substitution Test-symbols (iDSST-s)

    The iDSST-s is a processing speed test that is based on the pre-existing pencil and paper version of the Digit Symbol Substitution Test. The participants are presented with a legend that defines 9 symbols, with each symbol corresponding to a digit from 1 to 9. The participant is then presented with a conveyer belt in the middle of the screen that displays a series of empty boxes labelled with a number. The participant must select the symbol that corresponds to the number of a given highlighted box from symbol options presented at the bottom of the screen. The participant must try to place as many correct symbols in the boxes as possible over the duration of the test.

    Measured: From the end of the OL treatment period (Week 16) to Week 2 of the RW period (Week 18)

  8. Number of Participants With At Least One Treatment-Emergent Adverse Event (TEAE)

    An adverse event (AE) is any untoward medical occurrence in a clinical investigation participant administered a pharmaceutical product. A TEAE is defined as any event emerging or manifesting at or after the initiation of treatment with a study intervention or medicinal product or any existing event that worsens in either intensity or frequency following exposure to the study intervention or medicinal product.

    Measured: From Screening to End of study (approximately 31 weeks)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted23 Jan 2026
  2. Study start29 Jan 2026
  3. Primary completion17 Dec 2026 (estimated)
  4. Study completion17 Dec 2026 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 3
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Double blind
Who is masked
Participant, Investigator
Enrolment
98 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07363720
Sponsor's protocol ID
TAK-861-3003
Other IDs
2024-519466-44-00
Status last verified
Oct 2026
First submitted
7 Jan 2026
Last updated
30 Oct 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: Takeda provides access to the de-identified individual participant data (IPD) for eligible studies to aid qualified researchers in addressing legitimate scientific objectives (Takeda's data sharing commitment is available on https://clinicaltrials.takeda.com/takedas-commitment?commitment=5). These IPDs will be provided in a secure research environment following approval of a data sharing request, and under the terms of a data sharing agreement.

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing TAK-861 in people with Narcolepsy Type 1 (NT1) and Narcolepsy With Cataplexy, run by Takeda at 25 sites in 7 countries.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 3 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 30 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 25 sites in United States, Spain, France, Germany, Italy and 2 more countries. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Time to Loss of Response in the Epworth Sleepiness Scale (ESS) Score During the Up to 4-Week RW Period (time frame: Up to 4-week RW period). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07363720.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Oct 2026.

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