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REGN10597 Alone or with Cemiplimab in Adults with Advanced Solid Tumours, Melanoma, or Clear-Cell Renal-Cell Carcinoma

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 study is looking at melanoma, clear-cell renal-cell carcinoma, and other advanced solid tumors, which are cancers that have spread and are harder to treat. The medicines being studied are REGN10597, also called an anti PD-1-IL2RA-IL2 fusion protein, and cemiplimab (LIBTAYO), given through a vein. The purpose of the study is to find out how safe these medicines are and how well they may work against these cancers.

The study is done in two parts. In the first part, different doses of REGN10597 are tested alone and with cemiplimab to see how people tolerate the treatment. In the second part, more people receive the study treatment to learn more about its effect on the cancer. Participants are followed over time while the medicines are given and after treatment ends.

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

    Study treatment begins

    After joining the study, you receive REGN10597 by intravenous infusion, which means the medicine is given through a vein.

    The study also includes cemiplimab, given by intravenous infusion in the study arm that uses the combination treatment.

    The exact dose and schedule for REGN10597 and cemiplimab are not specified in the source data.

    The treatment is given during the study period, which is planned to run from 30 june 2026 to 28 april 2030.

  2. Step 2

    Safety monitoring during treatment

    During treatment, you are monitored for side effects, including serious side effects and side effects that may lead to stopping treatment or death.

    Your blood tests may be checked for laboratory abnormalities, which means results that are outside the normal range.

    The study records whether any dose-limiting toxicities occur. This means side effects that are severe enough to limit the amount of medicine that can be given.

  3. Step 3

    Tumor assessment during the study

    Your cancer is assessed to see whether the tumors shrink, stay the same, or grow.

    The study uses RECIST 1.1, which is a standard method for measuring how a tumor changes on scans.

    The study looks at objective response rate, best overall response, duration of response, disease control rate, time to response, and progression-free survival.

    Progression-free survival means the length of time during which the cancer does not get worse.

  4. Step 4

    Blood testing for the study medicine

    Blood samples are taken to measure the amount of REGN10597 in your blood.

    The study also checks for anti-drug antibodies, which are antibodies your body may make against the study medicine.

    These blood tests are used to see how the medicine behaves in the body over time.

  5. Step 5

    Study follow-up and treatment changes

    If you have side effects that are serious or if the study medicine is not tolerated, treatment may be stopped.

    The study records whether treatment is discontinued because of side effects.

    The study also records whether death occurs during treatment or follow-up.

Who can join the trial?

10 criteria

  • Be an adult, meaning 18 years of age or older.
  • For the dose escalation part of the study, have a solid cancer that has been confirmed by a tissue sample or cell sample. Histologically confirmed means the diagnosis was made by looking at tissue under a microscope. Cytologically confirmed means the diagnosis was made by looking at cells under a microscope.
  • For the dose escalation part of the study, the cancer must be locally advanced or metastatic. Locally advanced means the cancer has grown beyond where it started but not to distant parts of the body. Metastatic means the cancer has spread to other parts of the body.
  • For the dose escalation part of the study, the cancer must have gotten worse after standard treatment. Standard treatment means the usual approved treatment used for that cancer.
  • For the dose escalation part of the study, if an archival tissue sample is available, it must be submitted. Archival tissue means a stored tissue sample taken in the past.
  • For the dose expansion part of the study, have melanoma or clear-cell renal-cell carcinoma (ccRCC) confirmed by tissue or cell testing. Melanoma is a cancer of the cells that make skin pigment. Clear-cell renal-cell carcinoma is a type of kidney cancer.
  • For the dose expansion part of the study, meet the protocol-defined criteria for melanoma or ccRCC. Protocol-defined criteria means specific rules written in the study plan.
  • For the dose expansion part of the study, provide a fresh pretreatment biopsy during screening. A biopsy is a small sample of tissue taken from the body. Pretreatment means it is taken before study treatment starts. Fresh means a new sample collected for this study.
  • For the dose expansion part of the study, be willing to provide an additional exploratory biopsy at other time points if required. Exploratory means it is used to help researchers learn more about the treatment and cancer.
  • Meet all other inclusion criteria listed in the study protocol.

Who cannot join the trial?

9 criteria

  • Any previous treatment with interleukin 2 (IL-2), IL-15, or IL-7 if it was given by itself and not together with adoptive cell therapy (a treatment that uses a patient’s own immune cells).
  • Previous treatment with anti-PD-1 or anti-PD-L1 therapy, or with an approved systemic therapy (treatment that works throughout the whole body) or any previous systemic non-immunomodulatory biologic therapy (a biologic medicine that does not change the immune system) within the last 4 weeks, if this is defined in the study rules.
  • Received radiation therapy (high-energy treatment such as X-rays) or major surgery within 14 days before the first dose of the study drug, or has not recovered from side effects from those treatments.
  • Had previous anti-cancer immunotherapy (treatment that helps the immune system fight cancer) within 4 weeks before the study treatment, or stopped a previous anti-cancer immunotherapy because of severe side effects of grade 3 or 4 (serious or very serious) toxicity.
  • Has ongoing immune-related side effects before starting the study treatment.
  • Has a known allergy or hypersensitivity (strong allergic reaction) to any part of the study drugs.
  • Needs ongoing or continuous corticosteroid treatment (steroid medicine) of more than 10 mg of prednisone per day, or an equivalent anti-inflammatory dose, within 1 to 2 weeks before the first study dose.
  • Has an ongoing or recent autoimmune disease within the last 5 years, or any other condition that needed treatment with systemic immunosuppressive treatment (medicine that lowers the immune system).
  • Any other exclusion rule listed in the study plan also applies.
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Investigated drugs

  • cemiplimab

    is an immunotherapy given through a vein. It helps the body’s immune system recognize and attack cancer cells more effectively. In this trial, it is being studied by itself and also together with another treatment to see how safe it is and whether it may help control advanced solid tumors.

  • REGN10597

    is an experimental immunotherapy given through a vein. It is designed to help the immune system fight cancer by acting on immune signals that can boost the body’s ability to attack tumor cells. In this study, researchers are testing it alone and in combination with cemiplimab to learn more about its safety and early signs of anti-cancer activity.

What is already known about the treatment

  • Cemiplimab

    Cemiplimab is given as an intravenous infusion, meaning it is placed directly into a vein by a healthcare professional. It is an established cancer medicine in medical practice and is well described in the medical literature as an immune checkpoint inhibitor. It is used mainly to treat certain cancers such as melanoma and some advanced solid tumors, including clear-cell renal-cell carcinoma in some settings. At the molecular level, it blocks the PD-1 protein on immune cells, which helps the immune system recognize and attack cancer cells more strongly; it belongs to the class of anti-PD-1 monoclonal antibodies.

  • REGN10597

    REGN10597 is given by intravenous infusion as a powder that is first prepared into a solution before use, and it is administered by a healthcare professional. It is still an experimental medicine and is mainly known from clinical trial research rather than routine medical use. It is being studied for advanced solid tumors, including melanoma and clear-cell renal-cell carcinoma, to see whether it can help the immune system fight cancer. This medicine is designed to bind to PD-1 and also deliver interleukin-2 signals through the IL-2 receptor, so it may both remove a brake on immune cells and give them a growth signal; it belongs to the class of engineered immune-based cancer therapies.

Investigated diseases

Melanoma - Melanoma is a cancer that begins in pigment-producing cells, usually in the skin. It often starts as a changing mole or a new dark spot and can spread into nearby skin and deeper tissues over time. As it progresses, it may form larger skin lesions and spread to other parts of the body. Advanced Solid Tumours - Advanced solid tumours are cancers made up of solid masses in organs or tissues that have grown beyond their original site. They usually progress by increasing in size, invading nearby structures, and spreading to distant areas. This term describes later-stage solid cancers from different body sites rather than one specific disease. Clear-Cell Renal-Cell Carcinoma - Clear-cell renal-cell carcinoma is a type of kidney cancer that starts in the lining of small tubes in the kidney. It often grows as a mass in the kidney and may gradually spread into nearby tissue, blood vessels, or other organs. Over time, it can become more widespread and cause larger tumour deposits in different parts of the body.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase I/IITrial ID2025-523399-22-00Protocol codeR10597-ONC-22114Estimated enrolment233 patientsSponsorRegeneron Pharmaceuticals Inc.

sourced from the EU Clinical Trials Register and site verification

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