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Study of Dostarlimab and Drug Combination for Patients with Untreated Resectable Colon Cancer

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 type of colon cancer known as resectable colon cancer, specifically in patients with untreated T4N0 or Stage III colon cancer that shows certain genetic characteristics called dMMR (deficient mismatch repair) or MSI-H (microsatellite instability-high). The study will compare the effects of a new treatment using a medication called dostarlimab with the standard treatment usually given for this type of cancer. Dostarlimab is given as a solution for infusion, which means it is administered directly into the bloodstream through a vein.

The purpose of the study is to evaluate how effective dostarlimab is when used before and after surgery, compared to the usual care. Participants will receive either dostarlimab or the standard treatment, which may include medications like fluorouracil, capecitabine, folinic acid, and oxaliplatin. These medications are commonly used in cancer treatment and work by interfering with the growth of cancer cells. The study will last for a period of up to 12 months, during which participants will be closely monitored by healthcare professionals.

Throughout the study, participants will undergo regular assessments to check the progress of their treatment. This includes monitoring for any side effects and evaluating the response of the cancer to the treatment. The study aims to provide valuable information on whether dostarlimab can improve outcomes for patients with this specific type of colon cancer. Participants will receive care and support from the study team throughout the trial period.

The research process

The trial runs in 7 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, eligibility is confirmed based on specific criteria such as age, health status, and type of colon cancer.

    A signed informed consent is required to participate.

  2. Step 2

    Initial assessment

    An initial assessment is conducted to evaluate the current health status and confirm the presence of colon cancer.

    This includes providing a tumor tissue sample for analysis.

  3. Step 3

    Randomization

    Participants are randomly assigned to receive either dostarlimab monotherapy or the standard treatment regimen.

  4. Step 4

    Treatment phase

    For those receiving the standard treatment, medications include fluorouracil (25 mg/ml solution for injection or infusion), capecitabine (150 mg and 500 mg film-coated tablets), folinic acid (10 mg/ml concentrate for solution for infusion), and oxaliplatin (5 mg/ml concentrate for solution for infusion).

    The standard treatment involves a combination of intravenous and oral administration.

    Participants receiving dostarlimab will have it administered as a 500 mg concentrate for solution for infusion.

  5. Step 5

    Surgery

    Surgery is performed to remove the cancerous tissue, if deemed appropriate based on treatment response.

  6. Step 6

    Follow-up assessments

    Regular follow-up assessments are conducted to monitor health status and detect any recurrence of cancer.

    These assessments include radiological evaluations and pathological assessments of any new lesions.

  7. Step 7

    End of study

    The study is estimated to conclude by December 25, 2030.

    Final evaluations are conducted to assess the overall outcomes and any long-term effects of the treatment.

Who can join the trial?

11 criteria

  • Is at least 18 years of age.
  • Has an ECOG-PS of 0 or 1. ECOG-PS stands for Eastern Cooperative Oncology Group Performance Status, which is a scale used to assess how a patient's disease is progressing and how the disease affects their daily living abilities. A score of 0 means fully active, and 1 means restricted in physically strenuous activity but able to carry out light work.
  • Has adequate organ function, meaning the organs are working well enough to participate in the study.
  • Has untreated pathologically confirmed colon adenocarcinoma, which means the type of colon cancer has been confirmed by a pathologist and has not been treated yet.
  • Has resectable colon adenocarcinoma defined as clinically T4N0 or Stage III. This means the cancer can be surgically removed and is at a specific stage of development.
  • Has radiologically evaluable disease, meaning the cancer can be seen and measured using imaging tests like X-rays or scans.
  • Has a tumor demonstrating the presence of either a dMMR status or MSI-H phenotype. dMMR stands for deficient mismatch repair, and MSI-H stands for microsatellite instability-high, both of which are specific characteristics of the tumor.
  • Participants who are known to have Lynch syndrome and have been found to carry a specific germline mutation in an MMR gene (MLH1, MSH2, MSH6, PMS2) or EPCAM gene may be eligible to participate. Lynch syndrome is a genetic condition that increases the risk of certain types of cancer.
  • Provides a tumor tissue sample obtained at the time of or after the initial diagnosis of colon cancer.
  • Is willing to use adequate contraception to prevent pregnancy during the study.
  • Can provide a signed informed consent, which means agreeing to participate in the study after being informed about all aspects of it.

Who cannot join the trial?

10 criteria

  • Patients who have already received treatment for their colon cancer cannot participate.
  • Patients with colon cancer that cannot be surgically removed are not eligible.
  • Patients with a different type of colon cancer than the one specified in the study are excluded.
  • Patients with other serious health conditions that might interfere with the study are not allowed to join.
  • Patients who are unable to follow the study procedures or attend required visits cannot participate.
  • Patients who are pregnant or breastfeeding are not eligible for the study.
  • Patients who have participated in another clinical trial recently may be excluded.
  • Patients with allergies or reactions to the study medication or similar drugs cannot join.
  • Patients with a history of certain immune system disorders may not be eligible.
  • Patients who are taking medications that might interfere with the study treatment are excluded.
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Investigated drugs

Dostarlimab is a medication being studied for its effectiveness in treating certain types of colon cancer. It is used in patients who have not yet received treatment for their cancer, specifically those with a type of colon cancer that is resectable, meaning it can be surgically removed. The trial is comparing the use of dostarlimab before and after surgery to the standard treatments usually given for this type of cancer. The goal is to see if dostarlimab can improve outcomes for patients with this specific type of colon cancer.

What is already known about the treatment

Dostarlimab – Dostarlimab is administered intravenously, meaning it is given directly into a vein through an injection. It is currently being studied in clinical trials for its effectiveness in treating certain types of colon cancer, specifically untreated T4N0 or Stage III dMMR/MSI-H resectable colon cancer. The main therapeutic indication for dostarlimab is its use in cancer treatment, where it works by blocking a specific protein that helps cancer cells evade the immune system, thereby allowing the body's immune system to better attack the cancer cells. It is classified as an immune checkpoint inhibitor, a type of drug that helps the immune system recognize and fight cancer cells.

Investigated diseases

Colon Cancer – Colon cancer is a type of cancer that begins in the large intestine, which is part of the digestive tract. It often 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 disease can progress to more advanced stages, such as Stage III, where the cancer has spread to nearby lymph nodes but not to other parts of the body. In some cases, the cancer may exhibit specific characteristics like dMMR (deficient mismatch repair) or MSI-H (microsatellite instability-high), which can influence its behavior and response to treatment. Early detection and removal of polyps can prevent colon cancer from developing.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-503265-27-00Protocol code219606Estimated enrolment902 patientsSponsorGlaxosmithkline Research & Development Limited

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