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Relative Bioavailability of Pitolisant Tablets in Healthy Male Subjects for Narcolepsy Treatment

Verified siteRegistered drugNo placebo
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What is this trial about?

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

The study involves the rare sleep disorder Narcolepsy and its form with sudden muscle weakness called Narcolepsy with cataplexy. The medication being investigated is pitolisant, sold under the brand name Wakix, which is taken as a tablet to help reduce daytime sleepiness.

The purpose of the study is to compare how the body absorbs and processes different tablet formulations of the medication. Participants will receive a single dose of each of five tablet types, including the standard brand tablet and four new versions, with enough time between doses to let the drug clear from the body. Simple blood tests will be used to measure the pharmacokinetic profile, meaning how quickly the drug appears in the blood and how it is broken down into smaller pieces called metabolites, and to assess bioavailability, which indicates how much of the dose reaches the bloodstream.

Throughout the study, volunteers will be monitored for any side effects, and any discomfort will be recorded to evaluate safety and tolerance. The study is conducted with healthy adult men, and no patients with the sleep disorder are required to take part.

The research process

The trial runs in 16 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Randomization and assignment

    After joining the study you will be placed in a randomized sequence. this sequence decides the order in which you will receive each of the four test tablets and the reference tablet (wakix). the purpose is to ensure that the order does not influence the results.

  2. Step 2

    First tablet administration

    You will arrive at the clinic after fasting for at least ten hours. fasting means you have not eaten or drunk anything except water during that time.

    A single 40 mg dose of the assigned pitolisant tablet will be given orally. you will swallow the tablet with a glass of water.

  3. Step 3

    Pharmacokinetic observation after first dose

    Following the dose you will remain at the clinic while blood samples are taken at several time points. these samples allow the study team to measure how the drug is absorbed, distributed, metabolized and eliminated, which is called pharmacokinetic assessment.

    Any immediate side effects will be recorded as part of the safety and tolerance evaluation.

  4. Step 4

    Washout period before next dose

    After the observation period you will have a washout period during which no study medication is taken. this time allows the previous dose to leave your body completely before the next tablet is given.

  5. Step 5

    Second tablet administration

    You will repeat the same procedure as in step 2 with the next tablet in your assigned sequence. again you will fast, receive a single 40 mg oral dose, and swallow it with water.

  6. Step 6

    Pharmacokinetic observation after second dose

    Blood samples will be taken again at scheduled times to compare the drug’s behavior with the first tablet. safety and tolerance will continue to be monitored.

  7. Step 7

    Washout period before third dose

    Another washout period will occur before the third tablet is taken.

  8. Step 8

    Third tablet administration

    The same fasting and single 40 mg oral dosing procedure will be followed for the third tablet.

  9. Step 9

    Pharmacokinetic observation after third dose

    Blood sampling and safety checks will be repeated as before.

  10. Step 10

    Washout period before fourth dose

    A further washout period will separate the third and fourth administrations.

  11. Step 11

    Fourth tablet administration

    You will again fast and take a single 40 mg oral dose of the fourth tablet.

  12. Step 12

    Pharmacokinetic observation after fourth dose

    The same series of blood draws and safety observations will be performed.

  13. Step 13

    Washout period before fifth (reference) dose

    A final washout period will occur before the reference tablet is taken.

  14. Step 14

    Reference tablet administration (wakix)

    You will fast and receive a single 40 mg oral dose of the reference pitolisant tablet marketed as wakix.

  15. Step 15

    Final pharmacokinetic observation and safety check

    Blood samples will be collected to complete the comparison of all five tablets. final assessments of safety and tolerance will be recorded.

  16. Step 16

    Study completion

    After the last observations you will be released from the study procedures. any remaining questions about your experience can be discussed with the study staff.

Who can join the trial?

8 criteria

  • Has given written informed consent (you have signed a document showing you understand the study and agree to take part).
  • Is a male aged between 18 and 50 years old.
  • Is considered healthy based on a detailed medical history and physical exam, and does not have any serious ongoing illnesses (having mild seasonal or contact allergies is allowed).
  • Has a body mass index (BMI) between 18 and 30 kg/m² (a measure of body weight relative to height that falls within the normal to slightly overweight range).
  • Has normal laboratory test results, or any abnormal results are judged by the doctor to be not important for health.
  • Agrees to use an effective contraceptive method (such as condoms or choosing not to have sex) during the study and for a period after the last dose (up to five times the drug’s half‑life).
  • Has normal blood pressure and heart rate when measured lying down after five minutes: – Systolic blood pressure (the top number) between 90 and 145 mmHg, – Diastolic blood pressure (the bottom number) between 45 and 90 mmHg, – Heart rate between 40 and 90 beats per minute. If the numbers are outside these ranges, the doctor must decide they are not a health concern.
  • Has a normal 12‑lead ECG (a heart test that records electrical activity) or any irregularities are judged by the doctor to be not important. Normal ECG values include: – Heart rate 40‑90 beats per minute, – PR interval 120‑200 milliseconds (time for the electrical signal to travel from the atria to the ventricles), – QRS duration less than 120 milliseconds (time for the ventricles to contract), – QTcF less than 450 milliseconds (corrected time for the heart’s electrical recovery), – No significant rhythm problems or conduction blocks.

Who cannot join the trial?

23 criteria

  • If you are likely to have trouble following the study rules or cannot talk well with the study doctor (compliance).
  • If you are currently misusing drugs or drinking a lot of alcohol (more than 21 units a week, where one unit equals 4 cL of spirits) or have misused them in the past year (drug or alcohol abuse).
  • If you use more than 5 cigarettes (or similar nicotine products) each day and cannot stop while staying at the clinic (nicotine use).
  • If you drink more than 5 cups of coffee or other caffeinated drinks each day (over 500 mg of caffeine) and cannot stop during the clinic stay (caffeine).
  • If you have eaten or drunk grapefruit or grapefruit juice in the two days before the first dose and cannot avoid it during the study (grapefruit).
  • If you gave blood or lost a large amount of blood in the past two months (blood donation).
  • If a drug test shows any of the following substances: amphetamines, benzodiazepines, cocaine, opiates, barbiturates, or cannabinoids, at screening or before the first dose (positive drug screen).
  • If a breath test shows alcohol in your system at screening or before the first dose (positive alcohol breath test).
  • If blood tests show you have HIV, hepatitis B, or hepatitis C infection (positive serology for HIV/HBV/HCV).
  • If you have taken medicines that lower your immune system in the past six weeks (immune suppressive treatment).
  • If you had a fever, cough, or any infection caused by viruses, bacteria, fungi, or parasites in the past four weeks (viral, bacterial, fungal or protozoal infection).
  • If your veins are not good enough for repeated blood draws (unsuitable veins for venipuncture).
  • If you received any vaccine in the two weeks before screening (vaccination).
  • If you show signs of current or past tuberculosis infection (tuberculosis).
  • If the doctor thinks any other health problem could affect the study or put you at risk.
  • If you have been in another clinical study in the past two months, are in one now, or plan to join another study within two months after this one ends.
  • If you have important heart, kidney, liver, blood, stomach, lung, hormone, nerve, urinary, or mental health problems (cardiovascular, renal, hepatic, hematological, gastrointestinal, pulmonary, metabolic‑endocrine, neurological, urogenital, psychiatric diseases).
  • If you have asthma caused by allergies or known drug or food allergies (asthma of allergic origin, drug/food allergy).
  • If you have conditions that increase the risk of a rare heart rhythm problem called Torsades de Pointes, such as heart failure, low potassium, or a family history of Long QT Syndrome (Torsades de Pointes, Long QT Syndrome).
  • If you need to take any regular medicines, including herbal or over‑the‑counter drugs, during the study (concomitant medication).
  • If you have any important short‑term or long‑term illness, including known or suspected HIV or hepatitis B/C (acute or chronic disease).
  • If you are allergic to the study drug or any similar substances (hypersensitivity).
  • If you have taken any medication (except acetaminophen/paracetamol) that could affect the study, within two weeks before the first dose or not long enough for the drug to clear from your body (paracetamol exception).
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Investigated drugs

  • Wakix

    is a film‑coated tablet taken by mouth that contains the active ingredient pitolisant. In this study it is used as the reference or comparator product, meaning the researchers compare the new test tablets against this already approved medication to see how they perform.

  • pitolisant

    is a gastro‑resistant tablet taken by mouth that also contains the active ingredient pitolisant. In the trial it is the test product, and the researchers are evaluating four new formulations of this tablet to see how they compare with the reference product in terms of how the drug is absorbed and processed in the body.

What is already known about the treatment

  • Wakix

    This medication comes as a film‑coated tablet that is swallowed whole for oral use. It is an approved orphan drug that is listed in medical references for the treatment of narcolepsy, including narcolepsy with cataplexy. Pitolisant works by blocking the histamine H3 receptor in the brain, which raises histamine levels and helps keep a person awake. It is classified as a histamine H3‑receptor antagonist and a wake‑promoting agent.

  • Pitolisant

    The test product is a gastro‑resistant tablet taken by mouth, designed to dissolve later in the digestive tract. It contains the same active ingredient as Wakix and is currently being studied in clinical trials to assess its bioavailability and safety. Like Wakix, it treats narcolepsy and narcolepsy with cataplexy by blocking the histamine H3 receptor, increasing brain histamine and promoting wakefulness. It belongs to the same class of histamine H3‑receptor antagonists and wake‑promoting drugs.

Investigated diseases

  • Narcolepsy

    A chronic sleep disorder characterized by overwhelming daytime sleepiness and sudden, brief episodes of sleep. People often experience fragmented nighttime sleep and may fall asleep unintentionally during daily activities. Over time, the frequency of these sleep attacks can increase, leading to greater disruption of work, school, or social life. Some individuals may later develop sudden muscle weakness triggered by emotions, known as cataplexy. The condition typically persists throughout life, with symptoms gradually changing in intensity.

  • Narcolepsy with cataplexy

    This form of narcolepsy includes the same excessive daytime sleepiness as classic narcolepsy, but also features sudden loss of muscle tone triggered by strong emotions such as laughter or surprise. The episodes of muscle weakness are brief and can affect the face, limbs, or the whole body, causing temporary collapse. As the disease progresses, cataplexy attacks may become more frequent or severe, while daytime sleepiness often remains constant. Nighttime sleep continues to be disrupted, leading to a cycle of poor rest and increased daytime symptoms. The disorder is long‑lasting, with symptom patterns evolving over years.

Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase ITrial ID2023-505769-98-00Protocol codeP22-06Estimated enrolment16 patientsSponsorBioprojet Pharma

sourced from the EU Clinical Trials Register and site verification

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