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Study on Pembrolizumab for Patients with High-Risk Stage III Melanoma After Surgery

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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 a type of skin cancer called Stage III melanoma. Melanoma is a serious form of skin cancer that can spread to other parts of the body. The study is specifically looking at patients who have had a complete surgical removal of high-risk Stage III melanoma, which means the cancer has spread to the lymph nodes but has been fully removed by surgery. The trial is testing a treatment called pembrolizumab, also known by its code name MK-3475, which is an anti-PD-1 monoclonal antibody. This is a type of medication that helps the immune system recognize and attack cancer cells. The study will compare pembrolizumab to a placebo to see if it can help prevent the cancer from coming back.

The purpose of the study is to find out if pembrolizumab can improve the time patients remain free from cancer after surgery, known as recurrence-free survival. The study will also look at a subgroup of patients whose tumors have a specific protein called PD-L1 to see if pembrolizumab is more effective for them. Participants in the study will receive either pembrolizumab or a placebo through an intravenous infusion, which means the medication is given directly into a vein. The treatment will be administered over a period of up to 52 weeks, and patients will be monitored regularly to check for any signs of the cancer returning.

Throughout the study, patients will undergo regular check-ups and imaging tests like CT or MRI scans to monitor their health and the status of their cancer. The study aims to provide valuable information on whether pembrolizumab can help prevent the recurrence of melanoma after surgery, potentially offering a new treatment option for patients with high-risk Stage III melanoma. The trial is expected to continue until 2026, and the results will help determine the effectiveness of pembrolizumab in improving outcomes for melanoma patients.

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

    Initial Enrollment

    Upon joining the study, the patient undergoes a registration process. This involves providing written consent for tumor testing and ensuring eligibility based on specific criteria, such as age and medical history.

    A tumor sample is required for PD-L1 expression testing. This sample must be sent to a central laboratory for evaluation.

  2. Step 2

    PD-L1 Expression Confirmation

    The central laboratory confirms the PD-L1 expression status of the tumor sample. This step is necessary before proceeding to the next phase of the trial.

  3. Step 3

    Randomization and Treatment Assignment

    After confirmation of PD-L1 expression, the patient is enrolled and randomly assigned to one of two treatment groups: either receiving the pembrolizumab (KEYTRUDA) or a placebo.

    The treatment involves intravenous administration of pembrolizumab at a concentration of 25 mg/mL. The specific dosage and frequency are determined by the study protocol.

  4. Step 4

    Treatment Administration

    The patient receives the assigned treatment intravenously. The treatment schedule is designed to improve recurrence-free survival in patients with high-risk Stage III melanoma.

    The duration of the treatment is determined by the study protocol and continues until the study's end date or until specific criteria for discontinuation are met.

  5. Step 5

    Monitoring and Follow-up

    Throughout the trial, the patient's health and response to the treatment are closely monitored. This includes regular medical examinations and imaging tests to assess disease status.

    The primary goal is to evaluate recurrence-free survival, with additional assessments for distant metastases-free survival and overall survival.

Who can join the trial?

29 criteria

  • Must be at least 18 years old.
  • Must not have melanoma in the mucous membranes or eyes.
  • Melanoma with unknown origin is allowed.
  • Must have had a complete removal of Stage III melanoma that has spread to lymph nodes.
  • No history of melanoma spreading to nearby skin areas or having small satellite tumors.
  • Must provide a tumor sample for testing a protein called **PD-L1**. This sample should not have been treated with radiation before.
  • Must have a test to confirm the presence of **PD-L1** in the tumor.
  • Must have had surgery to remove affected lymph nodes, following specific guidelines for the procedure.
  • Must start treatment within 13 weeks after surgery, and only after the surgical wounds have healed.
  • Must have a full body scan to confirm no signs of cancer after surgery.
  • Must not have any signs of cancer returning or spreading to other parts of the body, including the brain.
  • Must have a known or untested status for a gene change called **BRAF mutation**.
  • Must have a good general health status, known as **ECOG performance status** of 0 or 1.
  • Must have healthy organs.
  • Must not have had any treatment for melanoma other than surgery, except for a specific treatment called **IFN** for certain cases.
  • Must not have a history of lung inflammation that required treatment with steroids.
  • Must not have any other active cancer, except for certain types that have been treated successfully.
  • Must not have an active autoimmune disease that needed treatment in the past 2 years.
  • Must not have an active infection that requires treatment.
  • Must not have a weakened immune system or be on immune-suppressing medication.
  • Must not have a history of **HIV**, active **Hepatitis B**, or **Hepatitis C**.
  • Must not have received any live vaccines within 30 days before starting the study treatment.
  • Must not have had previous treatment with certain immune therapies.
  • Must not be participating in another study or have used an investigational treatment recently.
  • Women who can become pregnant must have a negative pregnancy test before starting the study treatment.
  • Women who can become pregnant must use effective birth control during the study and for 120 days after the last treatment dose.
  • Women who are breastfeeding must stop nursing before starting the study treatment and for 120 days after the last treatment dose.
  • Must not have any condition that would prevent following the study protocol and schedule.
  • Must not be directly related to someone involved in conducting the study.

Who cannot join the trial?

9 criteria

  • Patients with a different type of cancer than the one being studied.
  • Patients who have not had their cancer completely removed by surgery.
  • Patients with cancer that has spread to other parts of the body beyond the lymph nodes.
  • Patients who have received certain treatments for their cancer in the past.
  • Patients with other serious health conditions that could interfere with the study.
  • Patients who are pregnant or breastfeeding.
  • Patients who are unable to follow the study procedures.
  • Patients who have allergies to the study medication.
  • Patients who are participating in another clinical trial.
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Investigated drugs

Pembrolizumab: This medication is an immunotherapy drug used in the trial to help the body's immune system fight cancer. It is specifically being tested to see if it can improve the time patients remain free from melanoma returning after they have had surgery to remove high-risk Stage III melanoma. Pembrolizumab works by blocking a specific protein that can stop the immune system from attacking cancer cells, thereby potentially preventing the cancer from coming back.

What is already known about the treatment

Pembrolizumab – Pembrolizumab is administered as an intravenous infusion, typically given in a clinical setting. It is currently well-established in medical literature as an immunotherapy treatment for various cancers, including melanoma. The main therapeutic indication for pembrolizumab in this trial is to improve recurrence-free survival in patients with high-risk Stage III melanoma after complete surgical removal of the tumor. At the molecular level, pembrolizumab works by blocking the PD-1 pathway, which helps the immune system recognize and attack cancer cells more effectively. It is classified as a monoclonal antibody and functions as an immune checkpoint inhibitor.

Investigated diseases

Stage III Melanoma – This is a type of skin cancer that has spread to the lymph nodes but not to distant parts of the body. It is classified into sub-stages IIIA, IIIB, and IIIC, based on the size and extent of the spread to the lymph nodes. In Stage IIIA, the cancer has metastasized to lymph nodes with metastasis greater than 1 mm. Stage IIIB and IIIC involve more extensive lymph node involvement, but without in-transit metastases, which means the cancer has not spread to areas between the primary tumor and the lymph nodes. The progression of Stage III melanoma involves the potential for further spread to other parts of the body if not managed.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-509136-25-00Protocol codeMK3475-054Estimated enrolment1 019 patientsSponsorMerck Sharp & Dohme LLC

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