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Long‑Term Safety, Tolerability and Efficacy of Azetukalner in Patients with Major Depressive Disorder

Verified siteInvestigationalNo placebo
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What is this trial about?

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

The study focuses on adults diagnosed with Major Depressive Disorder, a condition that causes a deep, lasting sadness, loss of interest in usual activities, and problems with sleep, appetite, and concentration. The medication being tested is named azetukalner and is taken as a small capsule by mouth once each day.

The purpose of the trial is to find out if long‑term treatment with azetukalner is safe and can be tolerated without serious side effects. Participants will attend regular clinic visits where they will have basic health checks, give blood samples, and complete short questionnaires about how they feel. The study will continue for many months so researchers can observe any issues that might develop over time.

Besides safety, the study will track changes in mood and daily functioning using several common rating tools: the HAMD-17 score, which is a list of questions that measures how severe the depression is; the SHAPS score, which looks at the ability to feel pleasure; the CGI-S rating, a doctor’s overall impression of illness severity; the Q-LES-Q-SF survey, which asks about enjoyment of everyday life; and the SDS questionnaire, which checks how depression affects work, social activities, and home tasks. These measures help determine whether the medication improves or worsens the condition.

The research process

The trial runs in 7 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Enrollment visit

    You attend the first clinic appointment after being selected for the study.

    The study staff obtain written consent and record your medical history, including the diagnosis of major depressive disorder.

    Baseline measurements are taken, such as depression rating scales, vital signs, and laboratory tests.

  2. Step 2

    Start of medication

    You begin taking the study drug azetukalner.

    The medication is provided as a 20 mg capsule for oral use.

    The dose is taken once each day, preferably at the same time each day, starting on day one of the study.

  3. Step 3

    First safety follow‑up

    Approximately two weeks after the first dose, you return to the clinic for a safety check.

    The visit includes a review of any side effects, a brief physical examination, and possibly a blood sample to assess how the medication is being processed.

  4. Step 4

    Regular monthly visits

    You schedule a clinic visit each month for the duration of the study.

    During each visit, the study team records depression rating scores (such as the HAMD‑17, SHAPS, CGI‑S, and quality‑of‑life questionnaires).

    The team also asks about any adverse events, checks vital signs, and provides a new supply of the azetukalner capsule.

    The medication continues to be taken daily between visits.

  5. Step 5

    Ongoing safety monitoring

    At any time you may experience side effects or new health concerns.

    You are instructed to contact the study clinic promptly to report serious or unexpected events.

    The study staff will evaluate the event and decide whether any action, such as dose adjustment or temporary interruption, is needed.

  6. Step 6

    Long‑term treatment phase

    You continue daily intake of azetukalner for the entire study period, which may last up to about sixteen months (from may 2026 through september 2027).

    The purpose of this phase is to assess the safety, tolerability, and effectiveness of the medication over an extended period.

  7. Step 7

    Final study visit

    After the last scheduled dose, you attend a final clinic appointment.

    Comprehensive assessments are performed to record the overall change in depression symptoms and to document any long‑term side effects.

    The study medication is discontinued, and you receive information about any further care that may be needed.

Who can join the trial?

7 criteria

  • Have finished the treatment part of an earlier Phase 3 study of azetukalner for major depressive disorder (a later‑stage trial that tests how well a medicine works and its safety).
  • Give written informed consent, meaning you understand the study, its procedures, and agree to follow them.
  • Be able to understand what will happen in the study and agree to follow all study requirements.
  • Agree to follow the contraception requirements (use of birth control methods) while taking the study drug.
  • Male participants must not donate sperm for at least three months after the last dose of the study medication.
  • Female participants must not donate ova (eggs) for at least three months after the last dose of the study medication.
  • Must be an adult (typically 18 years or older) and can be either male or female.

Who cannot join the trial?

7 criteria

  • If you left a previous study early, stopped the study drug early, or were removed from a previous study.
  • If you broke important study rules (called protocol deviations) in a prior azetukalner study and the doctor thinks that means you should not join this study.
  • If you cannot follow the study steps or the doctor decides you are not suitable for the study.
  • If you have any health problem, personal situation, or ongoing side effect (called an AE, which means an unwanted medical problem) from a previous study that the doctor believes puts you at too much risk or makes it hard to follow the study plan.
  • If you plan to join another clinical study with a different experimental drug or use an experimental device for any condition during this study or within 28 days after finishing this study.
  • If the doctor or a screening tool called the C-SSRS (Columbia‑Suicide Severity Rating Scale, which checks for risk of self‑harm) decides you are at significant risk of harming yourself or others.
  • If you are a woman who is pregnant, breastfeeding, or planning to become pregnant within 3 months after the last dose of the study drug.
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Investigated drugs

azetukalner is an oral capsule being tested in this study to see if it can be safely used for a long time by people with major depressive disorder. The trial will give participants the medicine every day and will closely watch them for any side effects or problems. Researchers want to learn how well the drug is tolerated and whether it can help improve mood over many months of treatment.

What is already known about the treatment

Azetukalner - It is taken as an oral capsule, usually 20 mg once daily. The drug is still experimental and not yet approved, with only early reports in medical literature. It is being tested to treat major depressive disorder, a condition with long‑lasting low mood. Azetukalner works by gently modulating brain chemicals that influence mood and is classified as an other antiepileptic medication.

Investigated diseases

Major Depressive Disorder - Major Depressive Disorder is a mental health condition characterized by persistent low mood, loss of interest, and reduced energy. It develops gradually or can appear suddenly, and symptoms last at least two weeks. People may experience changes in sleep, appetite, and concentration. The condition often deepens over time if underlying factors remain unchanged, leading to more intense feelings of sadness and difficulty in daily activities. Mood and motivation can fluctuate, but the overall pattern is a steady decline in emotional well‑being.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2025-523618-10-00Protocol codeXPF-010-D303Estimated enrolment465 patientsSponsorXenon Pharmaceuticals Inc.

sourced from the EU Clinical Trials Register and site verification

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