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Study on Pembrolizumab and Drug Combination for Patients with Localized Colon Cancer with Specific Genetic Markers

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 a treatment for patients with a specific type of colon cancer known as localized colon cancer. The trial will explore the effectiveness of a medication called pembrolizumab, also known by its code name MK-3475, in combination with a strategy called "watch-and-wait." This approach is being tested for patients whose cancer shows certain genetic features, specifically mismatch repair-deficient or microsatellite instability-high (dMMR/MSI-H) characteristics. These features mean that the cancer cells have trouble repairing their DNA, which can make them more responsive to certain treatments.

The purpose of the study is to evaluate how well this treatment strategy works over a period of time. Participants in the study will receive pembrolizumab, which is given as an infusion directly into the bloodstream. The study will also involve other medications, including capecitabine, oxaliplatin, and fluorouracil, which are commonly used in cancer treatment. These medications may be given in different combinations depending on the specific needs of the patient. The trial will monitor the success of the treatment strategy at various points, such as 6 months and 24 months after starting the treatment.

Throughout the study, participants will undergo regular check-ups and tests to assess their response to the treatment. This includes imaging tests like computed tomography (CT) scans to evaluate the size and spread of the cancer. The study aims to determine the safety and effectiveness of the treatment strategy, as well as its impact on the quality of life for participants. The trial will also track any side effects and overall survival rates to provide a comprehensive understanding of the treatment's benefits and risks.

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 treatment phase

    The treatment begins with the administration of pembrolizumab. This medication is given as an intravenous infusion, which means it is delivered directly into the bloodstream through a vein.

    The purpose of this phase is to evaluate the effectiveness of pembrolizumab in treating localized colon cancer with specific genetic characteristics.

  2. Step 2

    Medication schedule

    The dosage and frequency of pembrolizumab administration are determined by the study protocol. The treatment is typically administered every three weeks.

    The duration of this treatment phase is six months, during which the response to the medication is closely monitored.

  3. Step 3

    Monitoring and assessment

    Throughout the treatment, regular assessments are conducted to monitor the response to the medication. This includes imaging tests and possibly additional biopsies to evaluate the tumor's status.

    The primary goal is to determine if the tumor has responded to the treatment, allowing for a 'watch-and-wait' strategy instead of immediate surgery.

  4. Step 4

    Follow-up evaluations

    After the initial six-month treatment phase, follow-up evaluations are conducted to assess the long-term success of the treatment strategy.

    These evaluations occur at 6, 12, and 24 months after the start of the treatment, focusing on the patient's overall health and any changes in the tumor.

  5. Step 5

    Additional treatments

    If necessary, additional treatments may be considered based on the results of the follow-up evaluations. This could include further medication or surgical options if the tumor does not respond as expected.

Who can join the trial?

13 criteria

  • The patient must be able to give signed and dated informed consent, which means they understand the study and agree to participate.
  • Male patients must agree not to donate sperm and use a condom during sexual intercourse with women who can become pregnant, for the duration of the study and 4 months after the last dose of the study drug.
  • The patient must provide tissue samples from the primary tumor, which are collected during a procedure called a colonoscopy, along with images.
  • The patient must be willing and able to attend scheduled visits, follow the treatment plan, and undergo necessary tests and procedures.
  • The patient must be registered in the National Health Care System.
  • The patient must be at least 18 years old.
  • The patient must have an Eastern Cooperative Oncology Group Performance status (ECOG PS) of 0 or 1, which indicates they are fully active or have some symptoms but do not need bed rest.
  • The patient must have a newly diagnosed and confirmed type of cancer called colonic or upper third rectal adenocarcinoma, with biopsy material available from a colonoscopy.
  • The patient must have a tumor assessment done within 21 days before joining the study, showing the cancer is localized and can be surgically removed, with no spread to other parts of the body.
  • The patient must have a specific tumor status called dMMR and/or MSI-high, which involves certain proteins or markers being present or absent in the tumor.
  • The patient must have adequate blood, kidney, and liver function, confirmed by tests done within 14 days before starting the study treatment.
  • The patient must have certain blood clotting times within normal limits, unless they are on blood-thinning medication, in which case the levels must be appropriate as determined by the study doctor.
  • Female patients must not be pregnant or breastfeeding and must meet one of the following conditions: be of non-childbearing potential, have a negative pregnancy test within 72 hours before the first dose of the study drug, and if they can become pregnant, they must agree to use effective birth control during the study and for 4 months after the last dose of the study drug.

Who cannot join the trial?

7 criteria

  • Patients with any other type of cancer besides localized colon cancer cannot participate.
  • Patients who are not within the specified age range for the study cannot participate.
  • Patients who are not able to follow the study procedures or comply with the study requirements cannot participate.
  • Patients who have any medical condition that the study doctors believe would make it unsafe for them to participate cannot join the study.
  • Patients who are pregnant or breastfeeding cannot participate in the study.
  • Patients who have received certain treatments or medications that might interfere with the study cannot participate.
  • Patients who have participated in another clinical trial recently may not be eligible to join this study.
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Investigated drugs

Pembrolizumab is a medication used in this trial to treat patients with a specific type of colon cancer that has certain genetic characteristics, known as mismatch repair-deficient or microsatellite instability-high (dMMR/MSI-H). It is given before surgery to help shrink the tumor and potentially allow patients to avoid surgery altogether, following a "watch-and-wait" strategy. This approach is being tested to see if it can effectively manage the cancer while preserving the patient's quality of life.

What is already known about the treatment

Pembrolizumab – Pembrolizumab is administered intravenously, typically as an infusion over a set period. It is currently being studied in clinical trials for its effectiveness in treating localized colon cancer, particularly in patients with specific genetic markers known as mismatch repair-deficient or microsatellite instability-high (dMMR/MSI-H). The main therapeutic indication for pembrolizumab in this context is to serve as a neoadjuvant treatment, potentially allowing patients to avoid surgery through a watch-and-wait strategy. At the molecular level, pembrolizumab works by blocking the PD-1 pathway, which helps the immune system recognize and attack cancer cells. It is classified as an immune checkpoint inhibitor, a type of immunotherapy that enhances the body's natural defenses to fight cancer.

Investigated diseases

Localized Colon Cancer – This is a type of cancer that begins in the colon, which is part of the large intestine. In its localized form, the cancer is confined to the colon and has not spread to other parts of the body. It typically starts as small, noncancerous clumps of cells called polyps that form on the inside of the colon. Over time, some of these polyps can become cancerous. The progression of the disease involves the growth of cancer cells that can invade deeper layers of the colon wall. If not addressed, it may eventually spread to nearby lymph nodes or other organs.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-509322-22-00Estimated enrolment60 patientsSponsorAssociation Gercor

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