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Study Comparing Pembrolizumab and Placebo for Patients with Resected High-Risk Stage II Melanoma

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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 known as Stage II Melanoma, which has been surgically removed but is considered high-risk for returning. The study is comparing two treatments: a medication called Pembrolizumab (also known by its code name MK-3475) and a placebo. Pembrolizumab is a type of drug that is given through an intravenous infusion, which means it is delivered directly into the bloodstream through a vein. It is designed to help the body's immune system fight cancer cells.

The purpose of this study is to see if Pembrolizumab can help prevent the cancer from coming back after surgery. Participants in the study will be randomly assigned to receive either Pembrolizumab or a placebo. The study will be conducted over a period of time, and participants will receive regular infusions and follow-up care to monitor their health and the status of their cancer. The main goal is to compare how long participants remain free from cancer recurrence between the two groups.

Throughout the study, researchers will also look at other important outcomes, such as how long participants live without the cancer spreading to other parts of the body, overall survival rates, and any side effects experienced. This information will help determine the effectiveness and safety of Pembrolizumab as a treatment option for high-risk Stage II Melanoma.

The research process

The trial runs in 4 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Randomization

    Upon joining the study, participants are randomly assigned to one of two groups: one receiving pembrolizumab and the other receiving a placebo (normal saline). This process is double-blind, meaning neither the participant nor the researchers know which treatment is being administered.

  2. Step 2

    Treatment administration

    Participants receive their assigned treatment through an intravenous infusion. The treatment consists of KEYTRUDA (pembrolizumab) at a concentration of 25 mg/mL or a placebo. The infusion is administered at regular intervals as determined by the study protocol.

  3. Step 3

    Monitoring and follow-up

    Participants are monitored for recurrence-free survival (RFS), which is the primary goal of the study. This involves regular check-ups and imaging to ensure there is no return of melanoma.

    Secondary outcomes include monitoring for distant metastasis-free survival (DMFS), overall survival (OS), and recording any adverse events (AEs) experienced by participants. The number of participants who discontinue treatment due to adverse events is also tracked.

  4. Step 4

    Completion of study

    The study is estimated to conclude by October 12, 2033. Participants will continue to be monitored until the end of the study to gather comprehensive data on the long-term effects and efficacy of the treatment.

Who can join the trial?

8 criteria

  • The patient must be **12 years or older**.
  • The patient must have a **new diagnosis of Stage IIB or IIC cutaneous melanoma**. This means a type of skin cancer that has been confirmed by examining tissue under a microscope.
  • The patient must have had the melanoma **completely removed by surgery** and not received any other treatment for it.
  • The time between the last surgery and joining the study must be **12 weeks or less**.
  • The patient must have **no signs of cancer spreading** to other parts of the body, as shown by medical imaging tests.
  • The patient must have a **good level of daily functioning**. This is measured by specific scales: the **ECOG Performance Scale** or **Lansky Play-Performance Scale** for those 16 years or younger, and the **Karnofsky Performance Scale** for those older than 16 but younger than 18. A score of 50 or higher is required.
  • The patient must have **recovered well from any side effects or problems** from the surgery before starting the study.
  • Female patients must **not be pregnant or breastfeeding**. If they can have children, they must agree to use **birth control** during the study and for at least 120 days after the last treatment dose.

Who cannot join the trial?

10 criteria

  • Patients who have not had surgery to remove the melanoma.
  • Patients who do not have high-risk Stage II melanoma.
  • Patients who are not within the specified age range for the study.
  • Patients who are not able to follow the study procedures or instructions.
  • Patients who have other medical conditions that might interfere with the study.
  • Patients who are pregnant or breastfeeding.
  • Patients who are participating in another clinical trial.
  • Patients who have had another type of cancer in the past, unless it was treated and is no longer active.
  • Patients who have an infection that is not well controlled.
  • Patients who have a history of allergic reactions to the study medication.
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Investigated drugs

Pembrolizumab is a medication used in this clinical trial to help prevent the recurrence of melanoma, a type of skin cancer, after it has been surgically removed. It works by helping the immune system recognize and attack cancer cells, potentially reducing the risk of the cancer coming back.

What is already known about the treatment

Pembrolizumab – Pembrolizumab is administered as an intravenous infusion, typically given in a clinical setting under the supervision of healthcare professionals. It is currently well-established in medical literature and is approved for use in various cancers, including melanoma. The main therapeutic indication for this trial is resected high-risk stage II melanoma. 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 an immune checkpoint inhibitor, a type of immunotherapy.

Investigated diseases

Resected High-Risk Stage II Melanoma – This is a type of skin cancer that has been surgically removed but is considered high-risk due to its potential to return or spread. Melanoma originates in the pigment-producing cells of the skin and can be more aggressive than other skin cancers. In Stage II, the cancer is thicker and may have ulcerated, but it has not spread to nearby lymph nodes or distant sites. After resection, there is a focus on monitoring for recurrence, as the risk of the cancer returning is significant. The progression of this disease involves careful observation for any signs of the cancer coming back or spreading to other parts of the body.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2022-501966-23-00Protocol codeMK-3475-716Estimated enrolment1 015 patientsSponsorMerck Sharp & Dohme LLC

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