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Phase II Study of Zanubrutinib in Elderly, Treatment‑Naïve Patients with Chronic Lymphocytic Leukemia

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 patients with Chronic lymphocytic leukemia and Small lymphocytic lymphoma, two related types of blood cancer that develop slowly and affect white blood cells. The condition is considered rare and is more common in older adults. The treatment being tested is an oral medication called zanubrutinib, which is taken as a tablet each day and works by blocking signals that help cancer cells grow.

The purpose of the trial is to evaluate how effectively the zanubrutinib treatment can keep the disease from getting worse in elderly patients who have not received any prior therapy, with a focus on the length of time patients remain free of disease progression.

Participants will start the daily oral medication and will attend regular clinic visits where blood samples and simple health assessments are performed to monitor the disease and any side effects. The study follows patients for an extended period, adjusting the treatment plan if needed, and records how long the disease stays stable, overall survival, and quality of life measures.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Baseline Assessments

    After joining the study, you will undergo a series of examinations to record the current state of your disease. This includes blood tests, physical examinations, and any imaging that the study requires. The purpose is to have a clear starting point for evaluating the treatment.

    All results are kept confidential and are used only to compare later measurements with this initial baseline.

  2. Step 2

    Start of Medication

    You will begin taking zanubrutinib as the study drug. The prescribed dose is 320 mg taken by mouth (oral) each day.

    The medication is taken at the same time each day, preferably with water, and you will continue to take it unless the study protocol directs a change.

  3. Step 3

    Ongoing Medication Administration

    You will keep taking the daily dose of zanubrutinib 320 mg for the duration of the trial. The treatment continues until one of the following occurs: the disease shows progression, side effects become unacceptable, or the study reaches its planned end.

    The study may include a planned reduction (de‑escalation) of the dose after a certain period, following the protocol’s instructions.

  4. Step 4

    Regular Monitoring Visits

    You will attend scheduled clinic visits, typically every four weeks, where the study team will check your health status.

    During each visit you will have a physical exam, repeat blood tests, and a review of any side effects you may have experienced. These visits help determine the treatment’s safety and effectiveness.

  5. Step 5

    Additional Evaluations

    At specific times defined by the study, you will complete questionnaires and tests that measure quality of life, daily functioning, and cognitive status (for example, ADL/IADL, MMSE, SPPB, and MNA).

    These assessments provide information about how the treatment impacts your overall well‑being.

  6. Step 6

    End of Treatment and Final Assessments

    If the study determines that treatment must stop—because the disease has progressed, side effects are severe, or the study period ends—you will discontinue zanubrutinib.

    A final set of examinations, blood tests, and questionnaires will be performed to record the outcome of the treatment and any lasting effects.

Who can join the trial?

14 criteria

  • Sign and date an informed consent form, meaning you agree to join the study and understand what will happen.
  • Have sufficient kidney (renal) function, shown by a creatinine clearance of at least 30 ml/min, calculated with standard formulas (MDRD, CKD‑EPI, or Cockcroft‑Gault). This test tells how well your kidneys clean waste from the blood.
  • Have adequate liver function: a total bilirubin level less than 1.5 times the normal upper limit, and AST and ALT levels less than three times the normal upper limit, unless the results are caused by your CLL/SLL or a harmless condition called Gilbert’s syndrome. These blood tests check how well the liver is working.
  • If you are a man who could father a child, you must agree to use an acceptable method of birth control during treatment and for one week after the last dose.
  • Be covered by any social security system (for example, health insurance or government benefits).
  • Be able to understand and speak the country’s official language, unless a translator is allowed.
  • Be able to attend all study visits and follow the trial’s rules.
  • Be at least 80 years old when you sign the consent form (there is no upper age limit).
  • Have never received treatment for chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) and have a disease score of 4 or 5 on the Royal Marsden Hospital (RMH) or Matutes scoring system; for SLL, a detectable CLL‑type cell clone in the blood is required.
  • Need treatment according to the 2018 iwCLL guidelines, which are standard rules doctors use to decide when treatment is necessary.
  • Have an ECOG performance status of 0 to 2, a scale that measures how well you can carry out daily activities (0 = fully active, 2 = able to care for yourself but not able to work).
  • Have a life expectancy longer than 6 months.
  • Show adequate blood‑forming (hematopoietic) function within 7 days before enrollment: an absolute neutrophil count (ANC) of at least 0.75 G/L and platelets of at least 50 G/L (platelet transfusions can be given during screening if needed).
  • Have a hemoglobin level greater than 9 g/dL, regardless of whether you have received a blood transfusion.

Who cannot join the trial?

29 criteria

  • You have taken any treatment specifically for chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) before, including the drug rituximab used for autoimmune blood problems.
  • There is any sign or suspicion that your disease has changed into a more aggressive form called Richter transformation or into diffuse large B‑cell lymphoma (DLBCL).
  • You have another active cancer besides the one being studied, or you had a previous cancer less than two years ago (unless it was a very early skin cancer, certain in‑situ cancers, or a tiny prostate cancer as listed).
  • You have had a stroke or a brain bleed within the past six months.
  • You had major surgery within the 28 days before signing the consent form.
  • You have a known bleeding disorder such as hemophilia or von Willebrand disease.
  • You have an active Hepatitis C infection (the virus is still detectable in your blood). If the virus has been cleared, you may be eligible.
  • You have an active Hepatitis B infection (the virus is still detectable in your blood). Past infection that is no longer detectable is allowed.
  • You tested positive for HIV but are not stable on treatment (for example, low CD4 count, detectable virus, or recent AIDS‑related infection).
  • You are known or suspected to be allergic (hypersensitivity) or have had a severe allergic reaction (anaphylaxis) to the study drug or any of its ingredients.
  • You need to take warfarin or a combination of two antiplatelet drugs (vitamin K antagonists) for blood thinning. Other blood thinners are allowed.
  • You have significant heart problems, such as a heart attack within six months, unstable chest pain within three months, severe heart failure (class III or IV), uncontrolled high blood pressure, serious rhythm problems, a certain type of heart block without a pacemaker, or a left‑ventricular ejection fraction (measure of heart pumping) below 50%.
  • You are taking a strong or moderate inhibitor or inducer of the enzyme CYP3A4, which changes how many medicines are processed.
  • You are already participating in another clinical trial that could interfere with this study.
  • You received a live, weakened (attenuated) vaccine within the last six months.
  • You have used any standard or experimental cancer drug within 28 days before the first day of the study treatment.
  • You have taken corticosteroids (a type of steroid medication) at doses higher than 20 mg per day within one week before the first dose, except for inhaled, topical, or pre‑medication steroids.
  • You have any other serious medical condition, abnormal lab result, or psychiatric illness that the doctor thinks could affect your participation or the study results.
  • You have an uncontrolled or active infection such as a bacterial, viral, or fungal infection, including a positive test for cytomegalovirus (CMV).
  • You are deprived of your liberty by a court or administrative order.
  • You are hospitalized and cannot give consent.
  • You are an adult under legal protection (for example, a legal guardian makes decisions for you).
  • You have advanced liver disease classified as Child‑Pugh cirrhosis.
  • There is evidence that your CLL involves the central nervous system (brain or spinal cord).
  • You have severe chronic obstructive lung disease with low oxygen levels (hypoxemia).
  • You have severe diabetes.
  • You have a gastrointestinal condition that seriously impairs digestion or absorption, such as malabsorption syndrome or removal of part of the stomach or small intestine.
  • You have active or past autoimmune hemolytic anemia (AIHA) or idiopathic thrombocytopenic purpura (ITP) that requires steroid treatment higher than 20 mg daily.
  • You have a prior history of Richter transformation or DLBCL (as noted above).
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Investigated drugs

Zanubrutinib is an oral medication that blocks a protein called BTK, which helps certain blood‑cancer cells grow. In this study, it is being given to older patients who have never been treated for chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). The drug is taken by mouth, and the trial is looking at how well it works to keep the disease from getting worse, using a plan that may lower the amount of medicine over time.

What is already known about the treatment

ZANUBRUTINIB - Zanubrutinib is taken as an oral tablet, usually 320 mg once daily. It is an approved drug in many countries for treating chronic lymphocytic leukemia and small lymphocytic lymphoma and is also being studied in new trials. The medicine works by permanently blocking a protein called Bruton’s tyrosine kinase, which stops signals that make cancer B‑cells grow. It belongs to the class of Bruton’s tyrosine kinase inhibitors, a type of targeted small‑molecule therapy.

Investigated diseases

  • Chronic lymphocytic leukemia

    A cancer of the blood that starts in a type of white blood cell called a B‑lymphocyte. It usually develops slowly and the abnormal cells build up in the bone marrow and bloodstream. Over time, the disease can cause enlarged lymph nodes, spleen, or liver as the cells spread. The number of normal blood cells may gradually decrease, leading to fatigue or infections. The condition often remains stable for years before any noticeable change in disease activity.

  • Small lymphocytic lymphoma

    A cancer that originates in B‑lymphocytes and primarily appears as enlarged lymph nodes. It is considered the tissue‑based counterpart of chronic lymphocytic leukemia. The disease can extend to the spleen, bone marrow, and blood as it advances. Lymph node swelling may increase and new sites can become involved over time. Like its counterpart, the progression is generally slow, with periods of stability interspersed with gradual growth.

Trial detailsLast updated 12 Nov 2026
Age65+ yearsPhasePhase IITrial ID2025-525080-32-00Protocol codeZEN-CLLEstimated enrolment95 patientsSponsorLYSARC

sourced from the EU Clinical Trials Register and site verification

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