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Study on the Safety and Effectiveness of Pembrolizumab, Favezelimab, and Vibostolimab for Children and Young Adults with Blood Cancers or Solid Tumors

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 clinical trial is focused on studying the safety and effectiveness of a treatment for children and young adults with certain types of cancer, specifically hematologic malignancies and solid tumors. The treatment involves the use of a medication called pembrolizumab, which is being tested in combination with other investigational agents. These investigational agents include favezelimab and vibostolimab, which are proteins designed to help the immune system fight cancer. The study aims to determine how safe these treatments are and how well they work in treating these cancers.

Participants in the study will receive the treatment through an intravenous infusion, which means the medication is given directly into a vein. The study will be conducted in two parts. In the first part, researchers will focus on understanding the safety and how the body processes the investigational agents. In the second part, the study will continue to evaluate the safety and also look at how effective the treatment is in shrinking or controlling the cancer. The study will monitor participants for any side effects and measure how the cancer responds to the treatment.

The goal of this study is to gather information that could lead to new treatment options for young patients with these types of cancers. The study will run until 2029, allowing researchers to collect comprehensive data on the long-term effects and benefits of the treatment. This research is important for developing new therapies that could improve outcomes for children and young adults facing these challenging diseases.

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 specific medical conditions such as relapsed or refractory classical Hodgkin lymphoma, advanced melanoma, or certain solid tumors.

    Participants must have recovered from any side effects of previous cancer treatments and, if HIV-positive, must have well-controlled HIV on antiretroviral therapy.

  2. Step 2

    Initial assessment

    An initial assessment is conducted to evaluate the participant's health status and to establish baseline measurements for the study.

  3. Step 3

    Treatment administration

    Participants receive the study medication, which includes pembrolizumab and potentially other investigational agents such as favezelimab or vibostolimab.

    The medication is administered as an intravenous infusion, which means it is given directly into a vein through a drip.

    The specific dosage and frequency of administration are determined by the study protocol and may vary depending on the participant's condition and response to treatment.

  4. Step 4

    Monitoring and follow-up

    Participants are regularly monitored to assess the safety and effectiveness of the treatment.

    This includes measuring the concentration of the medication in the blood and checking for any side effects or adverse events.

    The study aims to evaluate the overall response rate to the treatment, as well as other outcomes such as disease control and progression-free survival.

  5. Step 5

    Completion of study

    The study is expected to continue until June 2029, with participants being followed up throughout this period.

    Upon completion, final assessments are conducted to gather comprehensive data on the treatment's impact on the participant's condition.

Who can join the trial?

8 criteria

  • The patient must have one of the following confirmed diagnoses:
    • Relapsed or refractory classical Hodgkin lymphoma (cHL), which means the disease has returned or is not responding to treatment. This can be in patients who have or have not been treated with a type of medicine called PD-1 inhibitors.
    • Advanced melanoma, a type of skin cancer, which can be in patients who have or have not been treated with PD-1 inhibitors.
    • Solid tumors that are either:
      • Microsatellite instability-high (MSI-H) or mismatch repair deficient (dMMR), which are specific characteristics of the tumor cells. These patients can have or have not been treated with PD-1 inhibitors.
      • Tumor mutational burden-high (TMB-H), which means the tumor has a high number of genetic changes. These patients can have or have not been treated with PD-1 inhibitors.
      • The patient must have recovered from all side effects of previous cancer treatments.
      • If the patient is infected with the human immunodeficiency virus (HIV), their HIV must be well controlled with medication.
      • The study is open to both male and female patients.
      • The study includes children and young adults.
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Investigated drugs

  • Pembrolizumab

    is a medication used in this trial to help the body's immune system fight cancer. It works by blocking a specific protein on cancer cells, which allows the immune system to better recognize and attack these cells. This medication is being tested for its safety and effectiveness in children and young adults with blood cancers or solid tumors.

  • Investigational Agents

    are new treatments being studied in this trial to see if they can help treat cancer. These agents are not yet approved for general use and are being tested to understand how they work in the body, their safety, and how well they can help treat different types of cancer in young patients.

What is already known about the treatment

Pembrolizumab – Pembrolizumab is administered intravenously and is currently being studied in clinical trials for its safety and effectiveness in treating hematologic malignancies or solid tumors in pediatric and young adult patients. It is an established medication in medical literature, primarily used for various types of cancer. The main therapeutic indication for pembrolizumab is to enhance the body's immune response against cancer cells. At the molecular level, it works by blocking the PD-1 pathway, which cancer cells use to evade the immune system. Pembrolizumab is classified as an immune checkpoint inhibitor.

Investigated diseases

  • Hematologic Malignancies

    These are cancers that begin in the blood-forming tissue, such as the bone marrow, or in the cells of the immune system. They often result in the production of abnormal blood cells that can interfere with normal blood functions. As the disease progresses, it can lead to symptoms like fatigue, fever, and frequent infections due to the compromised immune system. The abnormal cells can also accumulate in the bone marrow, affecting the production of healthy blood cells. Over time, this can lead to anemia, bleeding disorders, and other complications. Hematologic malignancies can include various types such as leukemia, lymphoma, and myeloma.

  • Solid Tumors

    These are abnormal masses of tissue that usually do not contain cysts or liquid areas. They can occur in various parts of the body, including organs, muscles, and bones. As solid tumors grow, they can press on nearby organs and tissues, causing pain and other symptoms. The progression of solid tumors can vary widely depending on their location and type. They can be benign, meaning non-cancerous, or malignant, meaning cancerous. Malignant solid tumors can invade nearby tissues and spread to other parts of the body.

Trial detailsLast updated 7 Oct 2026
Age0-17PhasePhase ITrial ID2023-507179-23-00Protocol codeMK-9999-01BEstimated enrolment52 patientsSponsorMerck Sharp & Dohme LLC

sourced from the EU Clinical Trials Register and site verification

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