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A study to evaluate the safety and effectiveness of petosemtamab and pembrolizumab in adults with non-small cell lung cancer

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

This study focuses on individuals with Non-Small Cell Lung Cancer, which is a common type of lung cancer. The research aims to evaluate how well the combination of petosemtamab and pembrolizumab works to treat this disease and to ensure its safety. Both medications are administered through an IV infusion, which means the medicine is delivered directly into a vein through a small tube.

The research process

The trial runs in 1 step.

  1. Step 1

    Treatment administration

    The treatment involves receiving two different medications through an intravenous infusion, which means the medicine is delivered directly into a vein.

    The first medication, petosemtamab, is administered as a 1500 mg dose via infusion.

    The second medication, pembrolizumab, is administered as a 400 mg dose via infusion.

Who can join the trial?

10 criteria

  • You must be at least 18 years old when you sign the consent form to participate.
  • You must be willing and able to follow all study rules, including using contraception (methods to prevent pregnancy) and signing a written agreement to join the study.
  • You must have healthy blood cell levels, which includes:
    • A platelet count (cells that help your blood clot) of 100 or more.
    • An absolute neutrophil count (a type of white blood cell that fights infection) of 1.5 or more.
    • A hemoglobin level (a protein in red blood cells that carries oxygen) of at least 9 g/dL.
    • You must not have received a blood transfusion in the 7 days before testing these levels.
    • Your kidney function must be good, measured by a creatinine clearance (a test that shows how well your kidneys filter waste) of at least 60 mL/min.
    • You must have at least one measurable tumor that can be seen on a scan like a CT scan or MRI. This tumor must be large enough to be measured accurately by the doctor.
    • Your performance status, which is a scale used to measure how well you can perform daily activities, must be 0 or 1 (meaning you are fully active or able to do light work).
    • The doctor must believe you have a life expectancy (how long you are expected to live) of at least 12 weeks.

Who cannot join the trial?

7 criteria

  • You cannot participate if you have untreated CNS metastases, which means cancer that has spread to your central nervous system (your brain or spinal cord).
  • You cannot participate if you have carcinomatous meningitis, which is a condition where cancer cells spread to the protective layers covering your brain and spinal cord.
  • If you have had cancer in your brain that was treated, you may still join if your radiographic stability is confirmed. This means that two brain scans taken at least 4 weeks apart show that the cancer has not grown or spread in the brain.
  • You cannot participate if you have neurologic symptoms (such as numbness, weakness, or balance issues) caused by the brain cancer or its treatment, unless these symptoms have completely gone away or returned to your normal state.
  • You must have finished taking any steroids (medications used to reduce swelling or inflammation) at least 3 days before receiving the study medicine.
  • You cannot participate if you have taken any experimental drugs in a clinical trial within 4 weeks before the first dose of this study treatment.
  • You are not allowed to participate if you have ever taken petosemtamab (the specific drug being studied) in any other clinical trial at any time in the past.
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Investigated drugs

  • Petosemtamab

    is a medication given through a vein as an infusion to help fight cancer cells in adults with non-small cell lung cancer.

  • Pembrolizumab

    is a type of therapy given through a vein as an infusion that helps the body's immune system recognize and attack cancer cells.

What is already known about the treatment

  • Petosemtamab

    This medication is an experimental drug provided as a liquid solution that is delivered directly into a vein through an intravenous infusion. It is currently being studied in clinical trials to see if it can help treat non-small cell lung cancer. As a targeted therapy, it works by attaching to specific proteins on the surface of cancer cells to disrupt their growth and survival.

  • Pembrolizumab

    This medication is an approved immunotherapy administered as a liquid solution through an intravenous infusion into the bloodstream. It is widely used in medical practice to treat various types of cancer, including non-small cell lung cancer. It works by blocking a specific protein that helps cancer cells hide from the body's immune system, allowing the natural immune response to find and attack the tumor.

Investigated diseases

Non-small cell lung cancer - This is a type of cancer that starts in the cells of the lung. It is the most common form of lung cancer and involves cells that are not small and round. The disease typically begins in the lining of the airways or in the lung tissue itself. As it progresses, abnormal cells grow and multiply uncontrollably within the lungs. These cells can eventually spread to nearby tissues or other parts of the body.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2025-522867-13-00Protocol codeMCLA-158-CL04Estimated enrolment180 patientsSponsorMerus B.V.

sourced from the EU Clinical Trials Register and site verification

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