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Study of Pembrolizumab for Children with Advanced Melanoma or PD-L1 Positive Solid Tumors and Lymphoma

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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 effects of a medication called pembrolizumab, also known by its code name MK-3475, in children with certain types of cancer. The cancers being studied include advanced melanoma, which is a serious form of skin cancer, and other solid tumors or lymphomas that have either returned after treatment or are not responding to existing treatments. The study also includes children with tumors that have specific characteristics, such as being PD-L1 positive or having a high number of genetic mutations, known as tumor mutational burden-high (TMB-H).

The purpose of the study is to understand how safe and tolerable pembrolizumab is for children and to see how well it works against these cancers. Pembrolizumab is given as an infusion, which means it is delivered directly into the bloodstream through a vein. The study will monitor the children for any side effects and measure how their tumors respond to the treatment. Some children in the study may receive a placebo, which is a substance with no active medication, to compare the effects of pembrolizumab.

Participants in the study will receive regular assessments to track their health and the progress of their cancer. These assessments will help researchers determine the effectiveness of pembrolizumab in shrinking or controlling the tumors. The study aims to provide valuable information that could lead to better treatment options for children with these challenging types of cancer.

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

    Joining the study

    Upon joining the study, participants will be required to sign an informed consent form. This document confirms understanding of the study and agreement to participate.

    Participants must meet specific criteria, such as being between 6 months and less than 18 years old, and having a type of cancer that is advanced, relapsed, or refractory.

  2. Step 2

    Initial assessments

    Before starting the treatment, participants will undergo various assessments to ensure eligibility. These may include medical history review, physical examination, and laboratory tests to check organ function.

    Female participants of childbearing potential will need to take a pregnancy test within 72 hours before the first dose of the study medication.

  3. Step 3

    Treatment administration

    Participants will receive the study medication, pembrolizumab, which is administered as a solution for infusion. This means the medication is given directly into a vein through an intravenous (IV) line.

    The dosage and frequency of administration will be determined by the study protocol and the participant's specific condition.

  4. Step 4

    Ongoing monitoring

    Throughout the study, participants will be regularly monitored for any side effects or adverse events. This includes routine check-ups and laboratory tests.

    The study aims to evaluate the safety and effectiveness of pembrolizumab in treating the specific types of cancer involved in the trial.

  5. Step 5

    Response evaluation

    Participants will undergo assessments to evaluate the response of their cancer to the treatment. This may involve imaging tests and other evaluations based on specific criteria.

    The study will assess the antitumor activity of pembrolizumab using established response evaluation criteria.

  6. Step 6

    Completion of study

    At the end of the study period, participants will have a final evaluation to assess their overall health and the outcomes of the treatment.

    Participants may be asked to continue follow-up visits to monitor long-term effects and gather additional data.

Who can join the trial?

13 criteria

  • Participants must be between 6 months and less than 18 years old on the day they sign the consent form.
  • Female participants who can have children must have a negative pregnancy test within 72 hours before the first dose of the study medication.
  • Female participants who can have children must either not be sexually active or use birth control during the study and for at least 120 days after the last dose of the study medication.
  • Male participants must use birth control methods that follow local regulations for clinical studies.
  • Participants must have adequate organ function, meaning their organs are working well enough to participate in the study.
  • Participants must have a type of cancer that is advanced or has spread and cannot be cured, or for which no standard treatment exists or is suitable.
  • Participants can have had any number of previous treatments.
  • Participants must have a sample of their tumor available, either from a previous biopsy or a new one if needed.
  • Participants must have advanced melanoma or a PD-L1-positive advanced, relapsed, or refractory solid tumor or lymphoma. PD-L1-positive means the tumor has a protein that may respond to certain treatments.
  • Participants must have a measurable disease based on specific criteria, meaning the cancer can be measured in size.
  • Participants with neuroblastoma that can be seen with a special scan called MIBG may join the study. Neuroblastoma is a type of cancer, and MIBG is a scan used to detect it.
  • Participants must have a score of 50 or higher on the Lansky Play Scale if they are between 6 months and 16 years old, or a Karnofsky score of 50 or higher if they are older than 16. These scores measure how well they can perform daily activities.
  • Participants must have adequate organ function, meaning their organs are working well enough to participate in the study.

Who cannot join the trial?

8 criteria

  • Patients who have a different type of cancer than those specified in the study.
  • Patients who are not between 6 months and less than 18 years old.
  • Patients with tumors that do not have a high number of mutations, except for certain types of tumors.
  • Patients with tumors that have a specific genetic feature called MSI-H or dMMR are excluded, except for certain conditions.
  • Patients who have not relapsed or whose cancer is not resistant to treatment.
  • Patients who are not able to tolerate the study medication.
  • Patients who have other medical conditions that might interfere with the study.
  • Patients who are not able to follow the study procedures.
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Investigated drugs

Pembrolizumab is a type of medication known as an immunotherapy. It works by helping your immune system fight cancer. Pembrolizumab targets a specific protein on the surface of certain immune cells, which can help your body recognize and attack cancer cells more effectively. In this clinical trial, pembrolizumab is being tested to see how safe it is for children with advanced melanoma or other types of tumors that have come back or are difficult to treat. The study aims to find out how well pembrolizumab works in shrinking these tumors and what side effects it might cause.

What is already known about the treatment

Pembrolizumab – Pembrolizumab is administered as an intravenous infusion, meaning it is given directly into a vein through a needle. It is currently being studied in clinical trials for its effectiveness in treating advanced melanoma and certain types of advanced or relapsed solid tumors and lymphomas in children. The main therapeutic use of pembrolizumab is to help the immune system recognize and attack cancer cells. At the molecular level, it works by blocking a protein called PD-1 on immune cells, which can help the immune system destroy cancer cells more effectively. Pembrolizumab is classified as an immune checkpoint inhibitor, a type of drug that helps the body's immune system fight cancer.

Investigated diseases

  • Advanced Melanoma

    Advanced melanoma is a type of skin cancer that has spread beyond the original site to other parts of the body. It begins in the melanocytes, which are the cells responsible for producing melanin, the pigment that gives skin its color. As the disease progresses, it can invade nearby tissues and organs, making it more challenging to manage. The spread of melanoma to distant organs is known as metastasis, which can affect the lungs, liver, brain, and bones. The progression of advanced melanoma can vary, with some cases spreading rapidly while others may progress more slowly.

  • PD-L1 Positive Malignant Solid Tumor

    PD-L1 positive malignant solid tumors are characterized by the expression of the PD-L1 protein on the surface of cancer cells. This protein can help tumors evade the immune system by inhibiting the activity of immune cells. These tumors can occur in various organs and tissues, leading to a range of symptoms depending on their location. As the disease progresses, the tumor may grow and spread to other parts of the body, a process known as metastasis. The presence of PD-L1 can influence the tumor's behavior and its interaction with the immune system.

  • Relapsed or Refractory Classical Hodgkin Lymphoma (rrcHL)

    Classical Hodgkin lymphoma is a type of cancer that originates in the lymphatic system, specifically affecting a type of white blood cell called lymphocytes. In relapsed or refractory cases, the disease returns after treatment or does not respond to standard therapies. The progression involves the growth of abnormal lymphocytes, which can form tumors in lymph nodes and other parts of the body. As the disease advances, it can impair the immune system's ability to function properly. The spread of lymphoma can lead to symptoms such as swollen lymph nodes, fever, and weight loss.

  • Microsatellite Instability-High (MSI-H) Solid Tumors

    MSI-H solid tumors are characterized by a high level of genetic mutations due to defects in the DNA mismatch repair system. These tumors can occur in various organs, including the colon, stomach, and endometrium. The progression of MSI-H tumors involves the accumulation of genetic errors, which can lead to uncontrolled cell growth and tumor development. As the disease advances, these tumors may invade surrounding tissues and metastasize to distant sites. The high mutation rate in MSI-H tumors can influence their behavior and response to the immune system.

  • Tumor Mutational Burden-High (TMB-H) Solid Tumors

    TMB-H solid tumors are defined by a high number of mutations within the tumor's DNA. These mutations can lead to the production of abnormal proteins that may be recognized by the immune system. TMB-H tumors can develop in various tissues and organs, leading to diverse clinical presentations. As the disease progresses, the tumor may grow and spread to other parts of the body, a process known as metastasis. The high mutational burden can affect the tumor's characteristics and its interaction with the immune system.

Trial detailsLast updated 2 Oct 2026
Age0-17PhasePhase ITrial ID2022-501257-36-00Protocol codeMK3475-051Estimated enrolment148 patientsSponsorMerck Sharp & Dohme LLC

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