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Study of MDX2003 in Adults with Relapsed or Refractory B‑Cell Malignancies

Fast replyInvestigationalNo 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 adults who have advanced B-cell malignancies, a type of blood cancer that starts in white‑blood cells called B cells. Participants must have disease that is relapsed/refractory, meaning the cancer has returned after previous treatment or has not responded to standard therapies. The investigational medicine being tested is MDX2003, which is given as an intravenous infusion, a process where the drug is slowly delivered into a vein through a small needle.

The main goal of the trial is to evaluate how safe the medicine is and to identify a dose that can be used in later studies, while also looking for early signs that the drug may shrink the cancer. Participants will receive a series of treatment doses over several weeks, with regular visits for medical examinations, blood tests, and imaging scans to monitor health and any side effects.

The trial is conducted in two parts: the first part focuses on finding the appropriate dose, and the second part looks at whether the cancer shows any reduction in size, which is called a response. Responses are assessed by comparing scans taken before and after treatment to see if tumors have gotten smaller.

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

    Initial assessment

    After enrollment, a baseline evaluation is performed. this includes a physical examination, blood tests, and imaging studies to document the current status of the b‑cell malignancy.

    The purpose of this assessment is to establish a reference point for later comparisons and to ensure that it is safe to begin treatment with mdx2003.

  2. Step 2

    First dose of mdx2003

    The first administration of mdx2003 is given as an intravenous infusion. an intravenous infusion means the medication is delivered slowly through a needle placed in a vein.

    The exact amount of drug, how often it is given, and the total length of treatment are determined by the study protocol and will be explained by the study team.

  3. Step 3

    Post‑infusion monitoring

    After each infusion, you will be observed for a period of time to check for any immediate side effects, such as changes in blood pressure, heart rate, or feeling unwell.

    Vital signs and any symptoms are recorded by the study staff.

  4. Step 4

    Subsequent dosing cycles

    Additional doses of mdx2003 are given according to the schedule defined in the trial, which may involve repeating the intravenous infusion at regular intervals (for example, every two weeks).

    Each cycle follows the same procedure of infusion, monitoring, and recording of any side effects.

  5. Step 5

    Regular safety and efficacy visits

    Throughout the treatment period, you will attend clinic visits where blood samples are taken and imaging may be repeated to assess how the disease is responding.

    These visits also allow the study team to evaluate safety by checking for adverse events, which are any undesirable effects that may occur.

  6. Step 6

    End‑of‑treatment evaluation

    When the planned number of infusions is completed, a final set of assessments is performed to determine the overall response of the b‑cell malignancy to mdx2003.

    This includes a physical exam, laboratory tests, and imaging to document any changes in the disease.

  7. Step 7

    Follow‑up period

    After treatment ends, you will be followed for a period of time to monitor long‑term safety and to see whether the disease remains controlled.

    Follow‑up visits may include periodic blood tests and examinations, but no further doses of mdx2003 are given unless the study protocol specifies otherwise.

Who can join the trial?

20 criteria

  • Provide informed consent before any study procedures are done, meaning you agree in writing to take part after understanding what will happen.
  • If you are a male whose partner could become pregnant, you must use a highly effective birth control method while taking the study drug and for about 6 months after the last dose.
  • Be willing and able to attend scheduled study visits and follow the required procedures.
  • Stop any other experimental medicines at least 4 weeks (or the time it takes for the drug to leave your body, called 5 half‑lives) before the first dose of the study drug.
  • Stop other cancer treatments before starting the study, including:
    • Chemo‑immunotherapy, toxin‑linked drugs, or biologic therapy (such as antibodies) for at least 4 weeks (or 5 half‑lives for biologics, whichever is shorter).
    • Radio‑linked drugs for at least 8 weeks.
    • Radiation therapy for at least 4 weeks, except limited palliative radiation that can be finished at least 7 days before the first dose.
    • CAR T‑cell therapy for at least 4 weeks.
    • Be 18 years of age or older.
    • Have a confirmed diagnosis of a B‑cell blood cancer that has returned or not responded after previous treatments, as defined by your doctor.
    • Have an ECOG Performance Status score of 0 to 2, which measures how well you can carry out daily activities (0 = fully active, 2 = up and about more than half the day).
    • Show CD19 or CD20 positivity on a recent pathology report (a lab test that confirms your cancer cells have these specific markers) performed within the last 3 months.
    • Have measurable disease, meaning at least one tumor node larger than 1.5 cm or an external lesion larger than 1.0 cm that can be seen on a CT, MRI, or PET‑CT scan.
    • Have adequate organ function, which includes:
      • Blood hemoglobin ≥ 9 g/dL (a measure of red blood cells).
      • White blood cell count (neutrophils) ≥ 1,000 per microliter.
      • Platelet count ≥ 50,000 per microliter.
      • Liver tests (bilirubin, AST, ALT) within safe limits.
      • Kidney function with a creatinine clearance ≥ 50 mL/min (a test of how well the kidneys filter waste).
      • If you are a female who could become pregnant, you must have a negative pregnancy test within 72 hours before the first dose of the study drug.
      • If you are a female who could become pregnant, you must agree to use a highly effective birth control method while taking the study drug and for about 6 months after the last dose.

Who cannot join the trial?

25 criteria

  • Having a known or suspected history of hemophagocytic lymphohistiocytosis (HLH), a rare but serious disorder where the immune system attacks the body’s own tissues.
  • Having ongoing side effects from previous cancer treatment (except mild hair loss or mild nerve problems) that the doctor believes make study participation unsafe.
  • Having lymphoma that involves the brain, spinal cord, or other parts of the central nervous system (CNS lymphoma) at the time of screening.
  • Having certain heart problems, such as:
    • Congestive heart failure that is moderate to severe (New York Heart Association Class III‑IV) or a heart pumping ability (ejection fraction) less than 45%.
    • A heart attack or a mini‑stroke (transient ischemic attack) within the past 6 months.
    • Unstable chest pain (unstable angina) within the past 6 months.
    • Any other serious heart condition that the doctor considers significant.
    • Having a past or current cancer other than the study’s target disease, except for:
      • Early‑stage cervical cancer (Stage 1B or less).
      • Non‑invasive basal cell or squamous cell skin cancers.
      • Superficial (non‑invasive) bladder cancer.
      • Prostate cancer with a very low PSA level (<0.1 ng/mL).
      • Any cancer that has been completely cured for more than 2 years.
      • Having any medical condition, treatment, or lab result that could interfere with the study’s tests, make it hard to stay in the study, or be unsafe for the participant, as judged by the investigator.
      • Having an active, uncontrolled infection that is severe (grade 3 or higher) or requires strong antibiotics and is not stable according to the doctor.
      • Having a confirmed autoimmune disease (or other disease) that needs long‑term high‑dose steroids (more than 10 mg/day of prednisone or equivalent) or immunosuppressive drugs within the past 6 months, unless a special medical review allows it.
      • Having received a live or live‑attenuated vaccine (such as measles, mumps, rubella, or yellow fever) within 4 weeks before the first study dose.
      • Having a past severe reaction called grade 4 cytokine release syndrome (CRS) or grade 4 immune‑effector cell‑associated neurotoxicity syndrome (ICANS) after any previous immune‑based therapy.
      • Testing positive for hepatitis B surface antigen, or having a positive hepatitis B core antibody with a positive hepatitis B PCR test, which indicates active infection.
      • Testing positive for hepatitis C antibody and also having a positive hepatitis C RNA test, indicating an active hepatitis C infection.
      • Having a known infection with human immunodeficiency virus (HIV).
      • Having a history of receiving a tissue or solid organ transplant from another person (except corneal transplants), or having had an autologous stem cell transplant within 100 days before the first study dose.
      • Being pregnant or breastfeeding.
      • Having a known severe allergy to any part of the study drug MDX2003 or its inactive ingredients, which could cause a serious allergic reaction.
      • Having a known allergy to the medications allopurinol or rasburicase.
      • Having a seizure disorder that requires ongoing medication at the time of screening.
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Investigated drugs

MDX2003 is an experimental drug that is being given through an IV infusion. In this early‑stage study, researchers are looking at how safe it is and how well patients can tolerate it. They are also trying to find the best dose to use in later studies and to see if the drug can shrink or control the growth of B‑cell cancers that have come back or did not respond to other treatments.

What is already known about the treatment

MDX2003 - MDX2003 is administered as an intravenous infusion of a sterile solution for infusion. It is currently an investigational drug being evaluated in early‑phase clinical trials and has not yet received regulatory approval for routine medical use. The medication is being studied for patients with relapsed or refractory B‑cell cancers, such as certain types of lymphoma. It works by attaching to a protein on the surface of B‑cells, signaling the immune system to destroy those cells, and is classified as a targeted biologic therapy.

Investigated diseases

Relapsed/refractory B-cell malignancies - B‑cell malignancies are cancers that originate from B lymphocytes, encompassing various lymphomas and leukemias. In relapsed disease the cancer returns after an initial response, while refractory disease fails to respond to standard therapy. These cancers spread through the blood and lymphatic system, causing enlargement of lymph nodes, spleen, or bone marrow. Over time, malignant B cells accumulate, increasing tumor burden and involving additional organ sites. The course is characterized by cycles of progression and resistance to treatment.
Trial detailsLast updated 4 Oct 2026
Age18+ yearsPhasePhase I/IITrial ID2026-526661-26-00Protocol codeMDX-2003-101Estimated enrolment80 patients

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).