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Study of Acasunlimab Alone and Combined With Pembrolizumab in Patients With Advanced Skin Melanoma That Returned or Did Not Respond to Prior Treatment

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 involves people with cutaneous melanoma, which is a type of skin cancer that has either come back after treatment or has not responded to previous treatment. The melanoma must be at an advanced stage, meaning it cannot be removed by surgery or has spread to other parts of the body. The study will test two medications. The first medication is acasunlimab, also known by its code name GEN1046, which will be given as a solution through a vein. The second medication is pembrolizumab, also known as Keytruda, which is already approved for treating cancer and will also be given through a vein. Some people in the study will receive acasunlimab alone, while others will receive acasunlimab together with pembrolizumab. All participants must have previously received treatment with a checkpoint inhibitor, which is a type of cancer immunotherapy that helps the immune system fight cancer cells.

The purpose of this study is to evaluate how well acasunlimab works against tumors when given alone and when given together with pembrolizumab. The study will also look at the safety of these treatments. The main way the study will measure how well the treatments work is by checking how many people have their tumors shrink or disappear after receiving the treatment. This will be done using imaging scans that are evaluated according to standard criteria for measuring tumor response.

During the study, participants will receive their assigned treatment through infusions into a vein. The treatment may continue for up to 36 months depending on how well it works and how well it is tolerated. Throughout the study, doctors will regularly monitor participants with physical examinations, blood tests, and imaging scans to check how the cancer is responding to treatment and to watch for any side effects. The study is expected to begin enrolling participants in late 2025 and continue until mid-2029.

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

    Treatment assignment

    Upon joining the study, you will be assigned to receive either acasunlimab alone or acasunlimab in combination with pembrolizumab.

    Both medications are given through intravenous infusion, which means the medication will be delivered directly into your vein through a tube.

  2. Step 2

    Treatment cycles

    The treatment is organized in cycles. Each cycle represents a specific period of time during which you will receive the study medication.

    The first day of the first cycle is called Cycle 1 Day 1, which marks the official start of your treatment in the study.

  3. Step 3

    Medication administration

    You will receive acasunlimab as an infusion, which means the medication will be slowly delivered into your bloodstream through a vein.

    If you are assigned to the combination treatment, you will also receive pembrolizumab as an infusion.

    The infusions will be administered at the study site during scheduled visits.

  4. Step 4

    Monitoring and assessments

    Throughout the study, your response to treatment will be evaluated using imaging scans to measure changes in your tumors.

    The assessment will follow RECIST v1.1, which is a standardized method for measuring whether tumors are shrinking, staying the same, or growing.

    Your doctor will review these results to determine how well the treatment is working.

  5. Step 5

    Safety monitoring

    During the study, you will be monitored for any side effects or unwanted reactions to the medications.

    Regular check-ups and tests will be conducted to ensure your safety throughout the treatment period.

  6. Step 6

    Study duration

    The study is expected to continue until July 2029.

    Your individual participation length will depend on how you respond to the treatment and your overall health status.

    You will continue receiving the study medication in cycles as long as the treatment is beneficial and you do not experience unacceptable side effects.

Who can join the trial?

7 criteria

  • You must be 18 years of age or older
  • You must have a confirmed diagnosis of cutaneous melanoma, which is a type of skin cancer, that has either come back after treatment, not responded to treatment, spread locally and cannot be removed by surgery, or has spread to other parts of the body
  • Your disease must have gotten worse during or after at least one previous treatment that included a type of drug called an anti-PD-1 antibody, which is a medication that helps your immune system fight cancer
  • You must have received at least 2 treatment cycles of an approved anti-PD-1 drug, either alone or combined with other treatments
  • If you received treatment before or after surgery and your cancer came back or got worse within 6 months after finishing that treatment, this counts as your first previous treatment
  • If your cancer has a specific change in a gene called BRAF V600 mutation, you should have already received treatment targeting this gene change, unless your doctor decided this treatment was not suitable for you due to other health conditions or previous side effects
  • You must have an Eastern Cooperative Oncology Group performance status of 0 or 1, which means you are able to carry out normal activities or have only minor symptoms that do not prevent you from doing light work

Who cannot join the trial?

3 criteria

  • The study has not provided specific exclusion criteria information in the available data
  • Please note that exclusion criteria are conditions or factors that would prevent you from joining a clinical trial, such as certain other medical conditions, previous treatments, or test results that might make the study unsafe for you or affect the study results
  • Contact the study team directly to learn about specific reasons why someone might not be able to participate in this trial
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Investigated drugs

  • Acasunlimab

    is an investigational medication being tested in this trial. It is designed to help the body's immune system fight cancer cells. This medication works by targeting specific proteins that help cancer cells hide from the immune system, allowing the body's natural defenses to recognize and attack the melanoma.

  • Pembrolizumab

    is a type of immunotherapy medication that helps the immune system fight cancer. It works by blocking a protein called PD-1, which prevents the immune system from attacking cancer cells. By blocking this protein, pembrolizumab allows the immune system to better recognize and destroy melanoma cells. In this trial, it is being tested in combination with acasunlimab to see if the two medications work better together than acasunlimab alone.

What is already known about the treatment

  • Acasunlimab

    Acasunlimab is an investigational medication currently being studied in clinical trials for the treatment of advanced melanoma, a type of skin cancer. It is being tested both alone and in combination with another cancer medication called pembrolizumab, specifically for patients whose disease has returned or not responded to previous checkpoint inhibitor treatments. The medication works by targeting specific molecules on immune cells to help the body's immune system recognize and attack cancer cells more effectively. It belongs to a class of drugs known as immunotherapy agents, which are designed to boost the natural defenses of the immune system against cancer.

  • Pembrolizumab

    Pembrolizumab is an approved immunotherapy medication given through an intravenous infusion (directly into a vein) that is widely used in cancer treatment. It is a checkpoint inhibitor that works by blocking a protein called PD-1 on immune cells, which allows the body's immune system to better identify and destroy cancer cells that would otherwise hide from immune detection. This medication is approved for treating various types of cancer, including melanoma, lung cancer, and several other cancers, and has become a standard treatment option in modern oncology. In this clinical trial, it is being combined with acasunlimab to evaluate whether the combination provides better results for patients with advanced melanoma.

Investigated diseases

  • Cutaneous Melanoma

    Cutaneous melanoma is a type of skin cancer that develops from melanocytes, which are the cells that produce pigment in the skin. The disease begins when these cells start growing abnormally and uncontrollably. In its early stages, melanoma appears as an unusual mole or dark spot on the skin that may change in size, shape, or color. As the disease progresses, cancer cells can grow deeper into the layers of the skin. Without intervention, the abnormal cells may spread to nearby lymph nodes and other parts of the body through the bloodstream or lymphatic system. Advanced melanoma can affect various organs including the lungs, liver, brain, and bones.

  • Relapsed or Refractory Melanoma

    Relapsed melanoma occurs when the cancer returns after a period of improvement or remission following previous treatment. Refractory melanoma refers to cases where the cancer does not respond to treatment or continues to grow despite therapy. In both situations, the cancer cells have either survived the initial treatment or developed resistance to it. The disease may reappear in the same location as the original tumor, in nearby tissues, or in distant parts of the body. These forms of melanoma can be more challenging to manage as the cancer cells have demonstrated the ability to evade or resist therapeutic approaches.

  • Locally Advanced Unresectable Melanoma

    Locally advanced unresectable melanoma is a stage of skin cancer where the tumor has grown extensively in the area where it started but cannot be completely removed through surgery. The cancer may have spread to nearby skin, tissues, or lymph nodes in a way that makes surgical removal impossible or unsafe. This condition typically includes Stage IIIB, IIIC, or IIID melanoma classifications. The tumor may be too large, located in a difficult area, or involve critical structures that prevent safe surgical removal. Despite being locally advanced, the cancer has not yet spread to distant organs in the body.

  • Metastatic Melanoma

    Metastatic melanoma, also known as Stage IV melanoma, occurs when skin cancer cells have spread from the original tumor to distant parts of the body. The cancer cells travel through the lymphatic system or bloodstream to reach other organs. Common sites where melanoma spreads include the lungs, liver, bones, and brain, though it can affect virtually any organ. At this stage, multiple tumors may be present in different locations throughout the body. The disease represents the most advanced form of melanoma progression.

Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2025-520468-16-00Protocol codeGCT1046-07Estimated enrolment166 patientsSponsorGenmab A/S

sourced from the EU Clinical Trials Register and site verification

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