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Study of Belrestotug and Dostarlimab for Patients with Untreated Advanced Non-Small Cell Lung Cancer

Fast replyRegistered 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 lung cancer known as Non-Small Cell Lung Cancer (NSCLC). The study is specifically looking at cases where the cancer has not been treated before and is either locally advanced, cannot be surgically removed, or has spread to other parts of the body. The trial will test the effectiveness and safety of a new treatment combination. Participants will receive either a combination of two medications, belrestotug and dostarlimab, or a combination of a placebo and another medication called pembrolizumab, which is also known by the brand name KEYTRUDA.

The purpose of this study is to compare how well the combination of belrestotug and dostarlimab works against the combination of pembrolizumab and a placebo in treating patients with a specific type of NSCLC that shows high levels of a protein called PD-L1. PD-L1 is a protein that can affect the immune system's ability to fight cancer. The study will involve participants receiving these treatments through an intravenous infusion, which means the medication is given directly into a vein.

Participants in the study will be randomly assigned to one of the two treatment groups. The study is designed to be double-blind, meaning neither the participants nor the researchers will know who is receiving which treatment. This helps ensure the results are unbiased. The trial will continue for a set period, during which the health and progress of the participants will be closely monitored to assess the effectiveness and safety of the treatments. The study aims to provide valuable information that could lead to improved treatment options for people with this type of lung cancer.

The research process

The trial runs in 6 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, you will be randomly assigned to one of two groups. This process is called randomization and ensures that each participant has an equal chance of receiving either the study medication or a placebo.

  2. Step 2

    Initial assessment

    An initial assessment will be conducted to confirm your eligibility. This includes reviewing your medical history, conducting physical examinations, and performing necessary tests to ensure you meet the study criteria.

  3. Step 3

    Treatment administration

    If you are in the group receiving the study medication, you will receive a combination of dostarlimab and belrestotug. These medications are administered through an intravenous infusion, which means they are given directly into your vein.

    If you are in the placebo group, you will receive pembrolizumab along with a placebo. Pembrolizumab is also administered through an intravenous infusion.

  4. Step 4

    Treatment schedule

    The treatment will be given at regular intervals as specified by the study protocol. The exact schedule, including the dosage and frequency, will be explained to you by the study team.

  5. Step 5

    Monitoring and follow-up

    Throughout the study, regular monitoring will be conducted to assess your health and the effects of the treatment. This includes physical exams, blood tests, and imaging studies.

    You will be required to attend follow-up visits as scheduled by the study team to ensure your safety and to collect data on the treatment's effectiveness.

  6. Step 6

    End of study participation

    At the end of your participation in the study, a final assessment will be conducted. This will include a review of your health status and any changes that have occurred during the study.

    You will receive information about any further steps or treatments that may be necessary after the study concludes.

Who can join the trial?

10 criteria

  • The patient must be able to give signed informed consent, which means they understand the study and agree to participate.
  • If the patient is a woman who can have children, she must agree to use birth control during the study and for at least 4 months after the last dose of the study medication. She must not be pregnant or breastfeeding.
  • The patient must be at least 18 years old or the legal age of consent in their area.
  • The patient must have a confirmed diagnosis of Non-Small Cell Lung Cancer (NSCLC) that is either locally advanced and cannot be removed by surgery or treated with radiation, or it has spread to other parts of the body.
  • The patient must not have received previous treatment for their advanced or metastatic NSCLC, except if they completed certain treatments at least 6 months before their current diagnosis.
  • The patient must provide a sample of their tumor tissue, which is a small piece of the tumor taken for testing. This sample should be from a site that has not been treated with radiation.
  • The patient's tumor must have a high level of a protein called PD-L1, as determined by a specific test.
  • The patient must have measurable disease, meaning there is at least one tumor that can be measured to see if it changes in size during the study.
  • The patient must have an ECOG Performance Status score of 0 or 1, which means they are fully active or have some symptoms but can still do light work.
  • The patient must have adequate organ function, which will be checked through blood tests to ensure their organs are working well enough to participate in the study.

Who cannot join the trial?

10 criteria

  • Patients with any other type of cancer besides Non-Small Cell Lung Cancer cannot participate.
  • Patients who have previously received treatment with the study drugs dostarlimab or belrestotug are not eligible.
  • Patients with a history of severe allergic reactions to similar drugs are excluded.
  • Patients with uncontrolled medical conditions that could interfere with the study are not allowed to join.
  • Pregnant or breastfeeding women cannot participate in the study.
  • Patients who are currently participating in another clinical trial are not eligible.
  • Patients with active infections that require treatment are excluded.
  • Patients with a history of autoimmune diseases, which are conditions where the immune system attacks the body, are not eligible.
  • Patients with a history of organ transplant are excluded from the study.
  • Patients with brain metastases, which are cancer cells that have spread to the brain, are not eligible unless they have been treated and are stable.
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Investigated drugs

  • Belrestotug

    is an experimental medication being tested in this clinical trial. It is designed to work with the body's immune system to help fight cancer cells. The goal of using belrestotug is to enhance the body's natural defenses to better target and destroy cancer cells in patients with a specific type of lung cancer.

  • Dostarlimab

    is a medication that helps the immune system recognize and attack cancer cells. It works by blocking a specific protein that usually helps cancer cells hide from the immune system. By blocking this protein, dostarlimab allows the immune system to detect and fight the cancer more effectively.

  • Pembrolizumab

    is a medication that also helps the immune system fight cancer. It works similarly to dostarlimab by blocking a protein that prevents the immune system from attacking cancer cells. This helps the immune system to better identify and destroy cancer cells in the body.

What is already known about the treatment

  • Belrestotug

    Belrestotug is administered as an injection, typically given in a clinical setting under the supervision of healthcare professionals. It is currently being studied in clinical trials for its potential use in treating non-small cell lung cancer, particularly in cases where the cancer is advanced and cannot be surgically removed. The medication works by targeting specific proteins on cancer cells, helping the immune system recognize and attack these cells more effectively. It is classified as an immunotherapy agent, which means it helps boost the body's natural defenses to fight cancer.

  • Dostarlimab

    Dostarlimab is given as an intravenous infusion, meaning it is delivered directly into the bloodstream through a vein. It is being investigated in clinical trials for its effectiveness in treating non-small cell lung cancer, especially in patients with high levels of a protein called PD-L1. Dostarlimab works by blocking a pathway that cancer cells use to hide from the immune system, allowing the body's natural defenses to better identify and destroy the cancer cells. It belongs to a class of drugs known as immune checkpoint inhibitors, which enhance the immune response against cancer.

Investigated diseases

Lung Cancer, Non-Small Cell – Non-Small Cell Lung Cancer (NSCLC) is a type of lung cancer that includes several subtypes, such as adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. It typically begins in the epithelial cells lining the lungs. The disease progresses as cancer cells grow and form tumors, which can invade nearby tissues and spread to other parts of the body. As the cancer advances, it may cause symptoms like persistent cough, chest pain, and difficulty breathing. The progression of NSCLC can vary, with some tumors growing slowly and others more rapidly. The disease is often diagnosed at an advanced stage due to the subtlety of early symptoms.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-504753-12-00Protocol code213823Estimated enrolment363 patientsSponsorGlaxosmithkline Research & Development Limited

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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).