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Study on Leflunomide and Hydroxychloroquine for Patients with Primary Sjögren's Syndrome

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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 the effects of a combination therapy using leflunomide and hydroxychloroquine for treating primary Sjögren's Syndrome, a condition that affects the body's moisture-producing glands, leading to symptoms like dry mouth and eyes. The study aims to evaluate the safety and effectiveness of this treatment combination over a period of 24 weeks, with an additional 24-week follow-up phase. Participants will receive either the active medications or a placebo, which looks like the real medication but does not contain the active ingredients.

During the study, participants will take the medications orally in the form of film-coated tablets. The trial will assess changes in disease activity and symptoms, such as dryness and joint pain, using various tests and patient-reported outcomes. The goal is to determine if the combination of leflunomide and hydroxychloroquine can improve the symptoms of primary Sjögren's Syndrome compared to a placebo.

The study will also explore whether certain molecular markers can predict how well a patient might respond to the therapy. This research is part of a larger effort to find more effective treatments for primary Sjögren's Syndrome and to understand the disease better. Participants will be monitored closely throughout the study to ensure their safety and to gather comprehensive data on the treatment's impact.

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

    Joining the study

    Upon joining the study, eligibility is confirmed based on criteria such as age, diagnosis of primary Sjögren's Syndrome, and other health factors.

    Informed consent is required to participate in the study.

  2. Step 2

    Initial treatment phase

    The initial phase lasts for 24 weeks and involves a randomized, placebo-controlled trial.

    Participants receive either leflunomide or hydroxychloroquine, or a placebo, administered orally in the form of film-coated tablets.

    The main goal is to assess the effectiveness and safety of the medications in treating primary Sjögren's Syndrome.

  3. Step 3

    Crossover phase

    After the initial 24 weeks, participants enter a single-arm crossover phase.

    During this phase, all participants receive the active medications, leflunomide and hydroxychloroquine, to further evaluate their effects.

  4. Step 4

    Open extension phase

    The study continues with an open extension phase, bringing the total duration to 48 weeks.

    Participants continue to receive the active medications, allowing for long-term assessment of treatment effects.

  5. Step 5

    Evaluation and monitoring

    Throughout the study, various health parameters are monitored, including changes in disease activity, dryness, and joint symptoms.

    The effectiveness of the treatment is measured using specific tests and patient-reported outcomes.

Who can join the trial?

5 criteria

  • Women and men, aged 18-75 years
  • Diagnosed with **primary Sjögren's Syndrome** according to the **ACR-EULAR 2016 Criteria** for pSS. This means the patient has been diagnosed with a specific condition called primary Sjögren's Syndrome using guidelines from two medical organizations.
  • **ESSDAI ≥5**. This is a score used to measure the activity of the disease. A score of 5 or more is required.
  • Use of a reliable method of contraception. This means participants must use a dependable way to prevent pregnancy.
  • Signed written informed consent. This means the patient must read and sign a document that explains the study and agrees to participate.

Who cannot join the trial?

3 criteria

  • Patients who do not have primary Sjögren's Syndrome cannot participate. This is a condition where the body's immune system attacks its own moisture-producing glands.
  • Patients who are not within the specified age range cannot participate. The age range for this study is from 18 to 65 years old.
  • Patients who are part of a vulnerable population cannot participate. This means people who might be at higher risk of harm or exploitation.
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Investigated drugs

  • Leflunomide

    is a medication that is being studied for its potential to help people with primary Sjögren’s Syndrome. It is typically used to reduce inflammation and slow down the immune system, which may help in managing symptoms of this condition.

  • Hydroxychloroquine

    is another medication involved in the study. It is commonly used to treat autoimmune diseases by reducing inflammation and modulating the immune system. In this trial, it is being tested in combination with Leflunomide to see if it can improve the symptoms of primary Sjögren’s Syndrome.

What is already known about the treatment

  • Leflunomide

    This medication is typically administered orally in tablet form. It is currently being studied in clinical trials for its effectiveness in treating primary Sjögren's Syndrome. Leflunomide is primarily used for its anti-inflammatory properties, often in autoimmune conditions. It works by inhibiting the synthesis of pyrimidine, which is essential for the proliferation of lymphocytes, thereby reducing inflammation. Leflunomide is classified as a disease-modifying antirheumatic drug (DMARD).

  • Hydroxychloroquine

    This medication is also administered orally in tablet form. It is being evaluated in clinical trials for its potential benefits in treating primary Sjögren's Syndrome. Hydroxychloroquine is commonly used for its anti-inflammatory and immunomodulatory effects. It functions by interfering with the communication of cells in the immune system, which helps to reduce inflammation. Hydroxychloroquine is classified as an antimalarial and is also used in the treatment of autoimmune diseases.

Investigated diseases

Primary Sjögren's Syndrome – This is an autoimmune disease where the body's immune system mistakenly attacks its own moisture-producing glands. It primarily affects the salivary and tear glands, leading to symptoms such as dry mouth and dry eyes. Over time, it can also affect other parts of the body, including joints, skin, and organs. The disease can cause fatigue and joint pain, and in some cases, it may lead to complications in organs like the kidneys and lungs. The progression of symptoms can vary widely among individuals, with some experiencing mild discomfort and others facing more severe issues.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-510904-36-00Estimated enrolment52 patientsSponsorUniversitair Medisch Centrum Utrecht

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