Skip to content
Clinical Trials – home

Rare diseases

Investigational molecules

Locations

Our offerNewsroom

Not yet recruitingRare disease

Study of Ibrutinib Plus Ritonavir in Adults with Chronic Lymphocytic Leukemia, Lymphoplasmacytic Lymphoma, and Mantle Cell Lymphoma

Verified siteRegistered drugNo placebo
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

What is this trial about?

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

The study focuses on three rare blood cancers: chronic lymphocytic leukemia, lymphoplasmacytic lymphoma, and mantle cell lymphoma. Participants receive oral tablets of two medicines, a standard cancer drug called ibrutinib and a medication known as ritonavir that is used to increase the effect of other drugs.

The purpose of the trial is to determine whether the added medication allows a lower dose of the cancer drug to achieve the same level of activity in the body and to evaluate the safety of this combination. First, a short initial period checks how much of the cancer drug reaches the bloodstream when the boost is used; then a longer follow‑up period monitors side effects, overall health, and how well the disease responds over about a year.

During the study, participants take the assigned tablets each day and attend regular clinic visits where blood samples are drawn and simple questionnaires are completed. Researchers look for any side effects, track changes in disease size, and ask about quality of life. Terms such as “systemic exposure” refer to the amount of medicine present throughout the body, while “response” means the cancer has shrunk or stopped growing, and “progression‑free survival” describes the time a person lives without the disease getting worse.

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

    After you agree to join the study, you sign an informed consent form that explains the purpose, procedures, possible risks, and your rights as a participant.

  2. Step 2

    Baseline Assessments

    You undergo a series of initial examinations, including medical history review, physical examination, laboratory tests, and any imaging that is required to document the status of your disease before treatment begins.

  3. Step 3

    Start of the Run‑in Phase Medication

    You begin taking ritonavir tablets at a dose of 100 mg by mouth each day.

    At the same time, you take ibrutinib tablets totaling 560 mg by mouth each day (for example, four 140 mg tablets).

    These medicines are taken daily for the duration of the run‑in phase as directed by the study team.

  4. Step 4

    Pharmacokinetic Blood Sampling

    During the run‑in phase, blood samples are collected at specific times after you take the medication to measure how much drug is in your bloodstream (parameters such as AUC0‑24, Cmax, Tmax, and Cmin).

    The purpose of these samples is to determine whether the combination provides adequate drug exposure.

  5. Step 5

    Quality‑of‑Life and Symptom Questionnaires

    You complete the EORTC QLQ‑C30 questionnaire, which assesses overall quality of life, and the PRO‑CTCAE questionnaire, which captures any symptoms or side effects you experience.

    These questionnaires are filled out at scheduled visits during the run‑in phase.

  6. Step 6

    Evaluation of Run‑in Results

    Study staff review the pharmacokinetic data to confirm that the drug levels are sufficient.

    If the exposure is adequate, you continue to the next stage of the study.

  7. Step 7

    Start of the Extension Phase Medication

    You continue taking the same daily doses of ritonavir (100 mg) and ibrutinib (560 mg) for up to 52 weeks, unless the study team advises otherwise.

  8. Step 8

    Regular Safety Monitoring Visits

    You attend clinic visits at regular intervals (for example, every 4 weeks) where blood tests, physical examinations, and assessments for adverse events are performed.

    The study team also checks how well you are following the medication schedule and records any reasons you might stop taking the drugs.

  9. Step 9

    Disease Response Assessment

    At the end of the 52‑week extension phase, imaging studies and other disease‑specific tests are performed to determine your response to treatment.

    Response categories include complete response (CR), very good partial response (VGPR), and partial response (PR).

  10. Step 10

    Final Study Evaluations

    During the last visit, overall survival, progression‑free survival, and any remaining quality‑of‑life data are collected.

    The study also records any final cost‑related information that may be relevant to the treatment approach.

Who can join the trial?

8 criteria

  • Must be at least 18 years old.
  • Must have been diagnosed with one of the following blood cancers: chronic lymphocytic leukemia (CLL), lymphoplasmacytic lymphoma (LPL), or mantle cell lymphoma (MCL), as defined by the 2024 World Health Organization (WHO) classification (a global system for naming diseases).
  • Must have been taking the medicine ibrutinib for more than 60 days before joining the study, and the dose must not have been reduced.
  • Must have a World Health Organization performance status of 0, 1, or 2 (a scale that measures how well a person can carry out daily activities, where 0 = fully active, 1 = some restriction, 2 = able to care for self but not work).
  • Must have adequate renal (kidney) and hepatic (liver) function according to laboratory tests, unless any problems are clearly caused by the cancer itself.
  • Must be able and willing to follow the study’s visit schedule and other requirements.
  • Must be capable of understanding the study and giving informed consent (agreeing to take part after being fully explained).
  • Must sign a written informed consent form.

Who cannot join the trial?

14 criteria

  • You have another cancer (current or past) that was not completely treated at least 2 years ago, except for common skin cancers (basal or squamous cell) or early‑stage cervical cancer.
  • You are currently receiving chemotherapy, radiation therapy or immunotherapy (treatments that kill or control cancer cells).
  • You are already taking part in another clinical study (research trial) and have not received special permission to join this one.
  • You have any psychological, family, social or travel situation that might make it hard for you to follow the study schedule and attend required visits.
  • You need to take medicines that strongly affect certain body enzymes (CYP3A, CYP2D6, UGT) or a transport protein called P‑glycoprotein, especially if those medicines require very exact dosing.
  • You are allergic to, cannot tolerate, or have a medical reason not to use any of the study drugs.
  • You have a severe or uncontrolled health problem, such as an infection that is not under control, certain blood‑cell disorders, diabetes, high blood pressure, or thyroid problems that are not well managed.
  • You have an active infection (bacterial, viral, fungal, mycobacterial, parasitic, etc.) that needs treatment with medicines at the time you would start the study, or within the two weeks before the first dose.
  • You have serious heart issues, including a heart attack in the past 3 months, very severe heart failure (the most advanced stage, called NYHA class IV), or unstable heart rhythm problems.
  • You have had a stroke or bleeding in the brain within the past 6 months.
  • You have symptoms caused by disease in the brain or spinal cord (central nervous system).
  • You have a history of not following medical instructions or are considered unreliable in taking medicines as prescribed.
  • You have dementia, significant mental impairment, or a psychiatric condition that prevents you from understanding the study and giving consent.
  • You are a fertile man or a woman who could become pregnant, unless you are surgically sterile, have been post‑menopausal for at least 2 years, or agree to use a highly effective form of birth control during the study and for three months after the last dose.
Clinical Trials Concierge

Prefer not to search? Our Concierge searches the trials for you.

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

  • Ritonavir

    is an oral medication taken as a film‑coated tablet. In this study it is used as a “booster” to increase the amount of another drug in the bloodstream. By slowing down the breakdown of the second medication, ritonavir helps keep its level higher for longer, allowing a lower dose of that drug to be effective. The trial is testing whether adding ritonavir to the treatment plan can safely raise the exposure of the targeted therapy without increasing side effects.

  • Ibrutinib

    is an oral cancer medication that comes in a film‑coated tablet. It is designed to block a specific enzyme that cancer cells need to grow, and it is approved for treating chronic lymphocytic leukemia, lymphoplasmacytic lymphoma, and mantle‑cell lymphoma. In this trial the drug is given at a reduced dose while ritonavir is added, to see if the boosted combination provides enough drug in the body to work as well as the standard higher dose, while possibly reducing toxicity.

What is already known about the treatment

  • Ritonavir

    This medication is taken by mouth as a film‑coated tablet. It is an approved drug that is widely used in HIV treatment and also to increase the blood levels of other medicines. Ritonavir works by blocking an enzyme that normally breaks down many drugs, so they stay in the body longer. It belongs to the class of protease inhibitors and is often called a pharmacokinetic booster.

  • Ibrutinib

    This drug is also taken orally as a film‑coated tablet and is approved for several blood cancers. It is used to treat chronic lymphocytic leukemia, lymphoplasmacytic lymphoma, and mantle‑cell lymphoma. Ibrutinib blocks a protein called Bruton’s tyrosine kinase, which cancer cells need to grow and survive. It is classified as a Bruton’s tyrosine kinase (BTK) inhibitor.

Investigated diseases

  • Lymphoplasmacytic lymphoma

    It is a cancer that begins in the lymph nodes and bone marrow, involving cells that resemble both lymphocytes and plasma cells. It often produces an abnormal protein called IgM that can be detected in the blood. Over time the disease can spread within the bone marrow and to other lymphoid tissues. It may cause the blood to become thick and lead to swelling of the spleen or liver. The condition usually progresses slowly, with the number of abnormal cells increasing gradually.

  • Chronic lymphocytic leukemia

    This is a cancer of white blood cells that starts in the bone marrow and moves into the bloodstream. The disease is characterized by a steady rise in a type of lymphocyte that does not function properly. These cells can accumulate in the bone marrow, lymph nodes, spleen and sometimes the liver. As the abnormal cells increase, they can crowd out normal blood cells. The disease typically advances slowly, with the abnormal cells growing over many years.

  • Mantle cell lymphoma

    It is a cancer that originates in B‑cells located in the outer edge, or mantle zone, of lymph nodes. The malignant cells can spread to the spleen, bone marrow, gastrointestinal tract and other organs. Over time the disease may cause lymph nodes to enlarge and can involve the blood and bone marrow. The amount of cancer cells can rise gradually, leading to more widespread involvement. The condition usually follows a pattern of slow growth with occasional periods of faster spread.

Trial detailsLast updated 14 Oct 2026
Age18+ yearsPhasePhase IITrial ID2026-526101-15-00Protocol codeHO185 CLLEstimated enrolment177 patientsSponsorHemato-Oncologie voor Volwassenen Nederland (Hovon) Stichting

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? Our Concierge searches the trials for you.

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