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Study on the Safety and Effects of ORX750 for Patients with Narcolepsy and Idiopathic Hypersomnia

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying two sleep disorders: narcolepsy and idiopathic hypersomnia. Narcolepsy is a condition that causes excessive daytime sleepiness and sudden sleep attacks, while idiopathic hypersomnia is characterized by excessive sleepiness without a known cause. The treatment being tested in this study is a medication called ORX750, which is taken in capsule form.

The purpose of the study is to evaluate the safety and tolerability of ORX750. Participants will be randomly assigned to receive either ORX750 or a placebo, which looks like the medication but does not contain the active ingredient. The study will last for a period of 28 days, during which participants will take the medication orally. Throughout the study, various assessments will be conducted to monitor the participants' health and any side effects they may experience.

Participants will undergo regular check-ups, including laboratory tests and heart monitoring, to ensure their safety. The study will also measure how the medication affects sleep patterns and daytime sleepiness. This research aims to provide valuable information about the potential benefits and risks of ORX750 for individuals with narcolepsy and idiopathic hypersomnia.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial visit

    Upon joining the study, you will attend an initial visit. During this visit, you will undergo a series of assessments to confirm your eligibility. These assessments include a review of your medical history, a physical examination, and laboratory tests such as blood and urine analysis.

    You will also be asked to stop taking any current medications for narcolepsy or idiopathic hypersomnia. This is necessary to ensure that the effects of the study medication can be accurately assessed.

  2. Step 2

    Randomization

    After the initial assessments, you will be randomly assigned to one of two groups. One group will receive the study medication, ORX750, and the other group will receive a placebo, which looks like the medication but does not contain the active ingredient.

    This process is double-blind, meaning neither you nor the study team will know which group you are in. This helps to ensure that the results are not biased.

  3. Step 3

    Medication administration

    You will take the assigned capsule orally once a day. The exact dosage and duration will be provided by the study team. It is important to take the medication as instructed to ensure the accuracy of the study results.

    You will continue this regimen for the duration of the study, which is expected to last until November 2025.

  4. Step 4

    Follow-up visits

    Throughout the study, you will attend regular follow-up visits. These visits are scheduled to monitor your health and the effects of the medication. They will include physical exams, laboratory tests, and assessments of your sleep patterns and daytime sleepiness.

    The study team will also monitor for any side effects or adverse reactions to the medication. It is important to report any new symptoms or changes in your health during these visits.

  5. Step 5

    End of study

    At the end of the study, you will have a final visit. This visit will include a comprehensive assessment similar to the initial visit, including a physical exam and laboratory tests.

    The study team will discuss the next steps with you, including any recommendations for continuing treatment outside of the study.

Who can join the trial?

5 criteria

  • Must be between 18 and 65 years old.
  • Must have a Body Mass Index (BMI) between 17 and 37 kg/m². BMI is a measure of body fat based on height and weight.
  • Must have a diagnosis of Narcolepsy Type 1 (NT1), Narcolepsy Type 2 (NT2), or Idiopathic Hypersomnia (IH) according to specific medical guidelines.
  • Must be willing and able to stop taking all medications used for treating narcolepsy or idiopathic hypersomnia.
  • Must be willing and able to follow additional study requirements.

Who cannot join the trial?

9 criteria

  • Patients with any other sleep disorders besides narcolepsy and idiopathic hypersomnia cannot participate. Narcolepsy is a condition that causes excessive sleepiness and sudden sleep attacks. Idiopathic hypersomnia is a condition where a person feels excessively sleepy during the day, even after a good night's sleep.
  • Patients who are not within the specified age range for the study cannot participate. The study is open to certain age groups only.
  • Patients who are part of a vulnerable population, such as those who cannot give informed consent, are not eligible to participate.
  • Patients with any medical conditions that might interfere with the study or the safety of the patient cannot participate.
  • Patients who are currently participating in another clinical trial are not eligible to join this study.
  • Patients who have a history of substance abuse or dependency may not be eligible to participate.
  • Patients who are pregnant or breastfeeding cannot participate in the study.
  • Patients who have had a recent major surgery or are planning to have surgery during the study period are not eligible.
  • Patients with any known allergies to the study medication or its ingredients cannot participate.
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Investigated drugs

ORX750 is a medication being studied for its potential to help people with narcolepsy and idiopathic hypersomnia. Narcolepsy is a condition that causes excessive daytime sleepiness and sudden sleep attacks, while idiopathic hypersomnia is characterized by excessive sleepiness without a known cause. The purpose of this study is to see how safe and tolerable ORX750 is for people with these conditions. Researchers are also looking at how the body processes the medication and how it affects the symptoms of these sleep disorders. By participating in this trial, patients will help determine if ORX750 could be a useful treatment option for managing their symptoms.

What is already known about the treatment

ORX750 – ORX750 is a medication currently being studied in a clinical trial for its potential use in treating narcolepsy and idiopathic hypersomnia, which are conditions that cause excessive daytime sleepiness. It is administered orally, meaning it is taken by mouth in the form of a pill or capsule. The main goal of the ongoing study is to assess the safety and tolerability of ORX750 in patients. At the molecular level, ORX750 is believed to work by affecting certain chemicals in the brain that regulate sleep and wakefulness, although the exact mechanism is still under investigation. This medication is part of a class of drugs that aim to improve alertness and reduce sleepiness in affected individuals.

Investigated diseases

  • Narcolepsy

    Narcolepsy is a chronic sleep disorder characterized by overwhelming daytime drowsiness and sudden attacks of sleep. People with narcolepsy often find it difficult to stay awake for long periods, regardless of the circumstances. The condition can cause significant disruptions in daily routines. It is often accompanied by cataplexy, which is a sudden loss of muscle tone triggered by strong emotions. Sleep paralysis and hallucinations may also occur. The disorder is linked to a deficiency of a brain chemical called hypocretin, which helps regulate wakefulness and REM sleep.

  • Idiopathic Hypersomnia

    Idiopathic hypersomnia is a sleep disorder where individuals experience excessive daytime sleepiness despite having a good night's sleep. Unlike narcolepsy, it does not typically involve sudden sleep attacks or cataplexy. People with this condition may struggle to wake up after sleeping and often feel unrefreshed upon waking. The excessive sleepiness can interfere with daily activities and may lead to prolonged nighttime sleep or frequent naps. The exact cause of idiopathic hypersomnia is unknown, and it is considered a diagnosis of exclusion. It is characterized by a persistent need for sleep and difficulty in maintaining alertness during the day.

Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-518929-15-00Protocol codeORX750-0201Estimated enrolment248 patientsSponsorCentessa Pharmaceuticals UK Limited

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