Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Not yet recruiting

Efficacy and safety of remibrutinib, pimecrolimus and tacrolimus in adults with severe chronic pruritus of unknown origin (CPUO): a randomized, placebo‑controlled trial

Verified siteRegistered drug
Clinical Trials Concierge

Prefer not to search on your own, or looking for clinical trials for a rare disease?

What is this trial about?

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

The trial looks at adults with severe Chronic Pruritus of Unknown Origin (CPUO), a condition where intense itching lasts for months and the cause cannot be found. The medication being tested is an oral tablet called remibrutinib. Participants may receive either the active tablet or a matching placebo that looks the same but contains no active drug.

The main goal is to see whether the tablet reduces the severity of itching better than the placebo after about three months of treatment. Participants will take one tablet each day for up to a year. They will keep a simple daily diary where they rate their itch on a scale from 0 (no itch) to 10 (worst possible itch); this helps researchers track any change over time. The study also includes follow‑up visits at several points to check sleep quality, overall feeling of symptom improvement, and safety through routine lab tests and vital sign checks.

Safety monitoring continues throughout the 52‑week period, and any side effects or health changes are recorded. The information gathered will help determine if the medication is both effective at lowering itch and safe for long‑term use in people with this difficult‑to‑treat condition.

The research process

The trial runs in 10 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Enrollment and Consent

    You are asked to sign a consent form confirming that you understand the study and agree to take part.

    The study staff records your basic health information and confirms that you have severe chronic pruritus of unknown origin.

  2. Step 2

    Baseline Assessments

    You complete a daily Worst-Itch Numerical Rating Scale (WI-NRS) diary for a short period to establish your starting itch level.

    You also answer questions about sleep disturbance using the Sleep Disturbance Numerical Rating Scale (SD-NRS) and rate the overall severity of your itch with the Patient Global Impression of Severity (PGIS) questionnaire.

  3. Step 3

    Randomization

    The study team randomly assigns you to receive either the active medication remibrutinib (LOU064) or a matching placebo tablet.

    Both you and the study staff remain unaware of which treatment you receive (double‑blind).

  4. Step 4

    Start of Study Medication

    You begin taking one oral film‑coated tablet each day.

    The tablet contains either remibrutinib or placebo; the exact dose is defined by the study protocol and is taken daily for up to 52 weeks.

  5. Step 5

    Daily Itch Diary

    Each day you record your itch intensity on the WI-NRS scale.

    You also note any sleep disturbance on the SD-NRS if instructed.

  6. Step 6

    Week 4 Visit

    You attend a study visit after four weeks of treatment.

    The study staff reviews your diary entries and checks whether your WI-NRS score has improved by at least four points compared with baseline.

  7. Step 7

    Week 12 Visit – Primary Efficacy Assessment

    You attend a study visit at the end of week 12.

    The team evaluates whether your WI-NRS score has improved by at least four points and records your PGIS rating to see if your itch is now none or mild.

    Your sleep disturbance rating (SD-NRS) is also reviewed.

  8. Step 8

    Continuation to Week 24

    You continue taking the study tablet daily.

    At week 24 you have another visit where your PGIS score is recorded again to assess longer‑term itch relief.

  9. Step 9

    Safety Monitoring Through Week 52

    You keep taking the tablet each day until week 52.

    During this period the study staff monitors for any side effects, performs laboratory tests, and measures vital signs at scheduled visits.

  10. Step 10

    End‑of‑Study Visit

    At week 52 you attend a final visit.

    All remaining assessments are completed, including final safety checks and a summary of your itch and sleep scores.

Who can join the trial?

9 criteria

  • Must be at least 18 years old when signing the consent form.
  • Must have had chronic pruritus (itchy skin lasting a long time) for at least 4 months before the screening visit.
  • The itch must be of unknown origin, meaning doctors have ruled out skin diseases, internal medical problems, nerve‑related causes, psychological causes, medicines, or allergies; dry skin alone is not considered the main cause because all participants will use moisturizers (emollients) during the study.
  • The itch must affect at least two of the following body areas: trunk (chest or back), arms, or legs. It cannot be only on one side or follow a nerve pattern (dermatomal distribution).
  • Must still have severe, ongoing itch despite using moisturizers and be a candidate for medication taken by mouth or injection (systemic therapy).
  • Must rate the itch as 7 or higher on a 0‑to‑10 scale called the WI‑NRS (Itch Numeric Rating Scale) at the screening visit.
  • Must have an average WI‑NRS score of 7 or higher over the 7 days before the baseline visit, recorded in an electronic diary.
  • Must have at least 4 daily itch scores recorded in the diary during those 7 days; if fewer scores are available, the baseline visit can be delayed, but the whole screening period cannot exceed 28 days.
  • Must rate overall itch severity as “severe” (score of 3) on the PGIS (Patient Global Impression of Severity) at both the screening and baseline visits.

Who cannot join the trial?

9 criteria

  • Active skin conditions such as eczema (atopic dermatitis) or psoriasis that could interfere with measuring the itch.
  • Known systemic condition or medication that the doctor believes is the main cause of the current itching.
  • Use of other investigational drugs (study medicines) too recently – you must stop them for a period called a “washout” (usually at least 5 drug half‑lives or 30 days for small pills, longer for biologic medicines) before joining the trial.
  • Recent use of biologic treatments studied for this itch, such as dupilumab or nemolizumab, within 3 months before randomization.
  • Active, chronic, or recurring infections that could keep you from participating, including tuberculosis, other opportunistic infections (like certain bacterial or fungal infections), or suspected HIV infection.
  • History of cancer (malignancy) in any organ, except for localized basal cell skin cancer or early‑stage cervical cancer, treated or untreated within the past 5 years.
  • Significant health problems that might affect safety or study results, including serious heart issues (such as a heart attack, unstable heart disease, severe heart failure classified as NYHA Class III/IV, irregular heart rhythms, or uncontrolled high blood pressure within the last year), nervous system disorders, mental health conditions, lung disease, kidney disease, liver disease, hormone or metabolic disorders, blood disorders, digestive system disease, or immune system deficiency.
  • High risk of bleeding or clotting disorders, including a history of serious stomach or intestinal bleeding that required medical treatment, or the need for strong blood‑thinning medicines. Low‑dose aspirin (up to 100 mg daily) or clopidogrel (up to 75 mg daily) alone are allowed, but using both together is not.
  • Liver disease or abnormal liver tests such as acute or chronic hepatitis, cirrhosis, liver failure, or blood test results (AST/ALT) more than 1.5 times the normal upper limit, or an INR (a clotting test) greater than 1.5 at screening.
Clinical Trials Concierge

Prefer not to search on your own, or looking for clinical trials for a rare disease?

Tell us about your condition – we search every trial in Europe and connect you with the right site.

We usually reply within a few days

Verified sites

All sites with verified contact details – recruitment status may not be available; ask directly

Trial locations

Where you can join this trial

Countries are shaded by recruitment status. Click a recruiting country to ask about joining there.

Not yet recruiting
Not finding your country?

Not sure what to do next?

Joining a clinical trial can seem overwhelming. We guide you step by step, so you know exactly what to expect and how we support you through the process.

See the full process and FAQ

Investigated drugs

  • remibrutinib

    is an oral medication taken as a film‑coated tablet. In this study it is being tested to see if it can lower the intensity of severe itching that has no known cause. The drug works by blocking a specific enzyme that contributes to the itch signal, and participants will take it every day for up to 52 weeks while researchers watch for improvement and any side effects.

  • tacrolimus

    is a topical cream or ointment applied directly to the skin. It is used in the trial as a background treatment that participants may already be using. Tacrolimus helps calm an overactive immune response in the skin, which can reduce inflammation and itching. It does not cure the condition but may support overall symptom control while the main study drug is being evaluated.

  • pimecrolimus

    is another topical medication applied to the skin. Like tacrolimus, it works by limiting immune activity that can cause skin irritation and itch. In the trial it is allowed as a background therapy, meaning participants can continue using it as part of their regular skin care routine while the study drug is tested.

  • corticosteroids

    (plain topical steroids) are anti‑inflammatory creams or ointments that are commonly used to relieve skin redness, swelling, and itching. In this trial they are permitted as background therapy, so participants may keep using them as needed. These steroids help control skin inflammation but are not the primary focus of the research.

  • antihistamines

    are oral medicines taken by mouth that block the action of histamine, a substance that can trigger itching and allergic reactions. In the study they are allowed as background treatment, meaning participants can continue their regular antihistamine use. These drugs aim to lessen overall itch sensations but are not being tested as the main investigational product.

What is already known about the treatment

  • Remibrutinib

    Remibrutinib is taken as an oral film‑coated tablet. It is currently an investigational drug being studied in clinical trials for chronic pruritus of unknown origin and other immune‑related conditions. The medicine works by blocking Bruton's tyrosine kinase, a protein that helps immune cells send signals that lead to itching. It belongs to the class of BTK inhibitors.

  • Tacrolimus

    Tacrolimus is applied to the skin as a topical preparation. It is an approved medication used to treat inflammatory skin disorders such as eczema. The drug binds to a protein called FKBP‑12 and blocks the enzyme calcineurin, which reduces the release of inflammatory chemicals. It is classified as a topical calcineurin inhibitor.

  • Pimecrolimus

    Pimecrolimus is applied to the skin as a topical cream or ointment. It is an approved treatment for atopic dermatitis and other itchy skin conditions. The medication inhibits calcineurin by binding to FKBP‑12, thereby decreasing activation of T‑cells and lowering inflammation. It belongs to the class of topical calcineurin inhibitors.

Investigated diseases

Chronic pruritus of unknown origin - A persistent itching condition that lasts for at least six weeks and has no identifiable skin disease, systemic illness, or external trigger. It can affect any area of the skin and may be severe enough to cause frequent scratching. Over time the intensity of the itch may remain stable or gradually increase, often leading to discomfort, disturbed sleep, and reduced daily activity.
Trial detailsLast updated 12 Nov 2026
Age18+ yearsPhasePhase IIITrial ID2026-526178-17-00Protocol codeCLOU064R12302Estimated enrolment128 patientsSponsorNovartis Pharma AG

sourced from the EU Clinical Trials Register and site verification

Want to learn more about this trial or check if you can participate?

Clinical Trials Concierge

Prefer not to search on your own, or looking for clinical trials for a rare disease?

Tell us about your condition – we search every trial in Europe and connect you with the right site.