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Study of Pembrolizumab and Olaparib for Patients with Advanced Colorectal Cancer with DNA Repair Deficiency

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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 treatments for advanced colorectal cancer, a type of cancer that affects the colon or rectum. The study involves two medications: Pembrolizumab and Olaparib. Pembrolizumab, also known by its code name MK-3475, is a medication given through an intravenous infusion, which means it is delivered directly into the bloodstream through a vein. Olaparib is taken orally in the form of film-coated tablets. The purpose of the study is to evaluate how well these medications work together in patients with a specific type of colorectal cancer that has a deficiency in DNA repair, known as homologous-recombination deficiency (HRD).

Participants in the study will receive a combination of Pembrolizumab and Olaparib. The study will monitor the response of the cancer to this treatment over a period of time. The treatment period for Pembrolizumab is up to 24 months, while Olaparib is administered for up to 42 months. The study aims to determine the effectiveness of this combination in controlling the disease and improving outcomes for patients with this specific type of colorectal cancer.

Throughout the study, participants will undergo regular assessments to track the progress of their cancer and any changes in their condition. These assessments will help researchers understand the impact of the treatment on the cancer and gather important information about the potential benefits and risks of using Pembrolizumab and Olaparib together. The study is designed to provide valuable insights into new treatment options for patients with advanced colorectal cancer that has specific genetic characteristics.

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 assessment

    Upon joining the study, an initial assessment is conducted to confirm eligibility. This includes a review of medical history and a physical examination.

    Blood samples are collected to ensure adequate organ function. This must occur within 7 days before starting the study treatment.

  2. Step 2

    Treatment initiation

    The treatment involves two medications: pembrolizumab and olaparib.

    Pembrolizumab is administered as an intravenous infusion. The specific dosage and frequency are determined by the study protocol.

    Olaparib is taken orally in the form of film-coated tablets. The dosage and frequency are specified in the study protocol.

  3. Step 3

    Treatment monitoring

    Regular monitoring is conducted to assess the response to treatment. This includes imaging studies and laboratory tests.

    The objective is to evaluate the response rate of the treatment using specific criteria.

  4. Step 4

    Follow-up assessments

    Follow-up assessments are scheduled to monitor disease progression and overall health.

    These assessments help determine the duration of response and any potential side effects.

  5. Step 5

    Completion of trial

    The trial is estimated to conclude by February 14, 2025.

    Final assessments are conducted to gather data on the effectiveness and safety of the treatment.

Who can join the trial?

11 criteria

  • Participants must be at least 18 years old and have a confirmed diagnosis of **colorectal cancer**.
  • Participants should have an **ECOG performance status** of 0 to 1, which means they should be fully active or have some symptoms but can still carry out light work. This assessment should be done within 7 days before starting the study treatment.
  • Participants must have proper organ function, which will be checked through blood tests taken within 7 days before starting the study treatment.
  • Participants should have **unresectable** (cannot be removed by surgery) locally-advanced or **metastatic colorectal cancer** (cancer that has spread to other parts of the body) and have shown disease progression confirmed by imaging tests.
  • Participants must have a specific type of genetic change called **DNA HRD**. This can be identified by certain genetic tests. If these tests show the required genetic changes, participants may be eligible for the study. If the first test is positive, a new biopsy (tissue sample) may be needed before starting the study treatment.
  • A previous tumor tissue sample is needed to confirm the **HRD status** using a validated test. This sample should not have been exposed to radiation before.
  • Participants must have received between 2 to 5 previous treatments for their cancer, including specific drugs like **fluoropyrimidines**, **oxaliplatin**, and **irinotecan**. They may have also received other treatments if their cancer type is suitable.
  • Participants must have received **oxaliplatin-based chemotherapy** in a setting where surgery was not possible and shown sensitivity to this treatment. This means they should have received a certain number of treatment cycles and had a period without disease progression for at least 9 months after the last treatment.
  • Participants with both **MSS** (microsatellite stable) or **MSI-H** (microsatellite instability-high) advanced colorectal cancer can join the study.
  • Participants or their legal representatives must provide written consent to join the study.
  • Participants must have measurable disease based on specific criteria (RECIST 1.1). If the cancer is in an area that was previously treated with radiation, it must have shown progression after the treatment to be considered measurable.

Who cannot join the trial?

6 criteria

  • Patients who have a different type of cancer other than colorectal cancer cannot participate.
  • Patients who do not have refractory metastatic colorectal cancer cannot participate. This means the cancer has spread to other parts of the body and is not responding to treatment.
  • Patients without DNA homologous-recombination-repair deficiency (HRD) cannot participate. This is a specific genetic condition where the DNA repair process is not working properly.
  • Patients who are not within the specified age range for the study cannot participate.
  • Patients who are not willing or able to follow the study procedures cannot participate.
  • Patients who are part of a vulnerable population, such as those unable to give consent, may not be eligible.
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Investigated drugs

  • Pembrolizumab

    is a type of immunotherapy that helps the body's immune system fight cancer. It works by blocking a specific protein on cancer cells, allowing the immune system to better recognize and attack these cells. In this trial, pembrolizumab is being used to treat advanced colorectal cancer.

  • Olaparib

    is a medication that targets cancer cells with specific genetic defects, such as those with homologous-recombination-repair deficiency. It works by interfering with the cancer cells' ability to repair their DNA, leading to cell death. In this trial, olaparib is used in combination with pembrolizumab to treat patients with advanced colorectal cancer.

What is already known about the treatment

  • Pembrolizumab

    This medication is administered intravenously and is currently being studied in clinical trials for its effectiveness in treating colorectal cancer. It is primarily used to help the immune system detect and fight cancer cells. Pembrolizumab works by blocking a specific protein on cancer cells, allowing the immune system to target and destroy them. It is classified as an immune checkpoint inhibitor.

  • Olaparib

    This medication is taken orally and is also under investigation in clinical trials for colorectal cancer treatment. It is mainly used to treat cancers with specific genetic mutations that affect DNA repair. Olaparib works by inhibiting an enzyme involved in DNA repair, leading to cancer cell death. It belongs to a class of drugs known as PARP inhibitors.

Investigated diseases

Colorectal cancer – This is a type of cancer that begins in the colon or rectum, parts of the large intestine. It often starts as small, noncancerous clumps of cells called polyps that form on the inside of the colon or rectum. Over time, some of these polyps can become cancerous. As the disease progresses, it can invade and damage nearby tissues and organs. It may also spread to other parts of the body, such as the liver or lungs, through the bloodstream or lymphatic system. Symptoms can include changes in bowel habits, blood in the stool, and abdominal discomfort.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-509095-42-00Protocol codeGEMCAD 2102Estimated enrolment40 patientsSponsorGrupo Espanol Multidisciplinar En Cancer Digestivo

sourced from the EU Clinical Trials Register and site verification

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).