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Study of petosemtamab with pembrolizumab compared to pembrolizumab alone in patients with head and neck cancer who have not received previous treatment for advanced disease

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 study focuses on patients with head and neck squamous cell carcinoma that has either come back (recurrent) or spread to other parts of the body (metastatic). The cancer in these patients must show a specific marker called PD-L1. The study will test two treatment approaches: one group will receive a combination of two medications - petosemtamab and pembrolizumab, while another group will receive pembrolizumab alone.

Both medications are given through an intravenous infusion (directly into a vein). Petosemtamab can be given at doses up to 1500 milligrams per day, while pembrolizumab can be given at doses up to 400 milligrams per day. The purpose of this study is to determine if combining these two medications works better than using pembrolizumab by itself for patients who have not received previous treatment for their advanced cancer.

The treatment period may last up to 24 months. During the study, patients will have regular check-ups to monitor their health and how well the treatment is working. The study will look at how long patients live and whether their tumors shrink in response to the treatment.

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

    Initial assessment

    Your eligibility for the trial will be confirmed through medical tests and examinations

    The medical team will check if you have head and neck cancer that has spread or come back locally

    A tissue sample will be tested in a laboratory to check if your tumor has a specific marker called PD-L1

    Your heart function will be checked to ensure it is working at 50% or better

    Various organ function tests will be performed to ensure you meet the health requirements

  2. Step 2

    Treatment assignment

    You will be randomly assigned to one of two treatment groups:

    Group 1: Treatment with both petosemtamab and pembrolizumab given through intravenous infusion

    Group 2: Treatment with pembrolizumab alone given through intravenous infusion

  3. Step 3

    Treatment period

    You will receive your assigned treatment through an intravenous infusion (medication given directly into your vein)

    Regular visits will be scheduled to monitor your health and assess how your cancer responds to treatment

    Imaging scans will be performed to measure any changes in your tumor

    Your doctor will monitor any side effects you may experience

  4. Step 4

    Follow-up assessments

    Regular check-ups will continue to track your progress

    Imaging scans will be performed to assess how your tumor responds to treatment

    Your overall health and survival will be monitored

    The study will continue until February 2028

Who can join the trial?

12 criteria

  • Must sign an informed consent form before any study procedures begin
  • Must be at least 18 years old
  • Must have confirmed head and neck squamous cell carcinoma (a type of cancer) that has either spread to other parts of the body or returned locally and cannot be cured with local treatment. The cancer must be in one of these areas: oropharynx (back of the throat), oral cavity (mouth), hypopharynx (lower throat), or larynx (voice box)
  • Must have tumors that express a specific protein called PD-L1 at certain levels, which will be tested in a laboratory
  • Must not have received previous systemic treatment (treatment that affects the whole body) for cancer that has spread or returned. Previous treatment for earlier-stage disease is allowed if the cancer did not progress for at least 6 months after platinum-based therapy
  • Must provide a tumor tissue sample for testing
  • Must have cancer that can be measured using imaging scans
  • Must have good physical function status (ECOG score of 0 or 1, meaning able to perform daily activities with minimal assistance)
  • Must have a life expectancy of at least 12 weeks
  • Must have good heart function (ejection fraction of 50% or higher)
  • Must have adequate organ function as determined by medical tests
  • People who are HIV positive may participate if they meet certain additional requirements

Who cannot join the trial?

13 criteria

  • History of treatment with anti-PD-1 or anti-PD-L1 therapy (types of immunotherapy)
  • Previous treatment with EGFR inhibitors (targeted cancer therapy)
  • Active brain metastases (cancer that has spread to the brain) or spinal cord compression
  • Uncontrolled or significant heart disease
  • Active autoimmune disease requiring systemic treatment
  • History of organ transplant
  • Active infection requiring therapy, including hepatitis B, hepatitis C, or HIV
  • Other active cancers requiring treatment within the past 3 years (except for adequately treated non-melanoma skin cancer or cervical cancer)
  • Pregnancy or breastfeeding
  • Known allergies or severe reactions to study medications
  • Participation in another clinical trial within 4 weeks before starting this study
  • Mental conditions that could interfere with study compliance
  • Any condition that, in the opinion of the study doctor, would make participation unsafe
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Investigated drugs

  • Petosemtamab

    is a medication being studied for treating head and neck cancer. It targets specific proteins on cancer cells and is designed to help the immune system fight cancer more effectively. This medication is being tested in combination with another drug to see if it works better than standard treatment alone.

  • Pembrolizumab

    is an immunotherapy medication that helps the body's immune system detect and fight cancer cells. It works by blocking a protein called PD-L1, which can prevent the immune system from attacking cancer cells. This medication is already approved for treating various types of cancer, including head and neck cancer.

What is already known about the treatment

  • Petosemtamab

    A novel investigational biologic medication administered through intravenous infusion, currently being studied in clinical trials for the treatment of head and neck squamous cell carcinoma (HNSCC). It is being evaluated in combination with pembrolizumab for patients with recurrent or metastatic PD-L1 positive HNSCC as a first-line treatment option. The drug is designed to target specific molecular pathways involved in cancer growth and progression.

  • Pembrolizumab

    An immunotherapy medication administered through intravenous infusion that belongs to the class of PD-1 inhibitors, which helps the immune system detect and fight cancer cells. It is approved for treating various types of cancer, including head and neck squamous cell carcinoma, by blocking the PD-1 pathway that cancer cells use to hide from immune system attack. This medication works by enhancing the ability of the body's T-cells to identify and destroy cancer cells.

Investigated diseases

Head and Neck Squamous Cell Carcinoma (HNSCC) - A type of cancer that begins in the flat squamous cells that line the moist surfaces inside the head and neck region. This cancer can develop in various areas including the mouth, throat, larynx, and nasal cavity. The cancer typically starts in the squamous cells and can spread to nearby tissues and lymph nodes. When it becomes recurrent, it means the cancer has returned after initial treatment, while metastatic indicates it has spread to other parts of the body. The disease can affect normal functions like eating, speaking, and breathing.
Trial detailsLast updated 4 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2023-510323-30-00Protocol codeMCLA-158-CL03Estimated enrolment795 patientsSponsorGenmab A/S

sourced from the EU Clinical Trials Register and site verification

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