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Study on the Effects of Rapcabtagene Autoleucel and Drug Combination for Patients with Severe Refractory Inflammatory Muscle Diseases

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 the effects of a new treatment called YTB323 in people with severe inflammatory muscle diseases known as idiopathic inflammatory myopathies (IIM). These are conditions where the body's immune system mistakenly attacks its own muscles, causing inflammation and weakness. The main treatment being tested is rapcabtagene autoleucel, which is a type of cell therapy that uses the patient's own immune cells, modified to better fight the disease. This treatment is given as a single infusion directly into the bloodstream.

The purpose of the study is to see if rapcabtagene autoleucel can provide better results compared to other treatments chosen by doctors. Participants will receive either the new treatment or a different treatment selected by their doctor. The study will last for about a year, during which participants will be monitored to see if there is an improvement in their condition. The study will also look at the safety of the treatment and any side effects that may occur.

In addition to YTB323, other medications that may be used in the study include rituximab, mycophenolic acid, tacrolimus, tocilizumab, fludarabine phosphate, and cyclophosphamide. These medications are commonly used to manage symptoms and control the immune system in people with inflammatory muscle diseases. The study aims to provide valuable information on how effective and safe these treatments are for people with severe forms of these conditions.

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 treatment phase

    The trial begins with the administration of rituximab through an intravenous infusion. This medication is given to help manage the symptoms of severe inflammatory myopathies.

    Following the initial infusion, fludarabine phosphate is administered intravenously. This medication is used to prepare the body for the main treatment.

  2. Step 2

    Main treatment phase

    The main treatment involves a single infusion of rapcabtagene autoleucel (YTB323). This is a specialized treatment designed to target and improve the condition of severe inflammatory myopathies.

    The goal of this phase is to achieve a moderate improvement in the Total Improvement Score (TIS) by Week 52.

  3. Step 3

    Supportive care phase

    After the main treatment, supportive medications are provided. Mycophenolic acid and tacrolimus are taken orally to help maintain the effects of the main treatment and manage the immune response.

    Additionally, tocilizumab is given through an intravenous infusion to further support the treatment process.

  4. Step 4

    Monitoring and follow-up phase

    Throughout the trial, regular monitoring is conducted to assess the safety and effectiveness of the treatment. This includes checking vital signs, conducting laboratory tests, and performing ECG evaluations.

    The trial aims to measure improvements in the Total Improvement Score (TIS) and other health parameters by Week 52.

Who can join the trial?

7 criteria

  • You must sign a form to show you understand and agree to take part in the study.
  • You need to be a man or woman aged between 18 and 65 years old.
  • You should have a diagnosis of myositis, which is a condition that causes muscle inflammation, according to specific medical guidelines from 2017.
  • You must test positive for **MSA**, which stands for **myositis-specific antibodies**. These are special proteins in the blood that help diagnose myositis.
  • You should have tried high-dose **GC**, which means glucocorticoids, a type of medication, but it didn't work well for you. You also need to have tried two other treatments without success.
  • You must have active disease, which means your condition is currently causing symptoms, confirmed by a special committee.
  • At the time of screening, you should have severe myositis that meets certain criteria.

Who cannot join the trial?

4 criteria

  • Patients who have a different condition than the one being studied, which is **severe refractory idiopathic inflammatory myopathies**. This means the study is only for those with this specific muscle condition that does not respond to treatment.
  • Patients who are not within the specified age range for the study. The study has specific age requirements that participants must meet.
  • Patients who are not able to give informed consent or understand the study requirements. This means participants need to be able to understand what the study involves and agree to take part.
  • Patients who are part of a vulnerable population that the study is not designed to include. This could mean groups that need special protection or consideration.
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Investigated drugs

Rapcabtagene Autoleucel is a type of therapy that uses modified T cells to target and treat severe refractory idiopathic inflammatory myopathies. In this trial, it is given as a single infusion to help improve the condition of patients who have not responded well to other treatments. The goal is to see if this therapy can provide a significant improvement in the patients' symptoms over a period of 52 weeks.

What is already known about the treatment

Rapcabtagene Autoleucel – This medication is administered as a single infusion and is currently being studied in clinical trials for its effectiveness in treating severe refractory idiopathic inflammatory myopathies. It is in the experimental phase and not yet widely available in medical practice. The main therapeutic indication is for patients with this specific type of muscle inflammation that does not respond to standard treatments. Rapcabtagene autoleucel works by using genetically modified T cells to target and attack the disease-causing cells in the body. It is classified as a type of gene therapy, specifically a CAR T-cell therapy, which is a cutting-edge approach in treating certain immune-related conditions.

Investigated diseases

Severe Refractory Idiopathic Inflammatory Myopathies – This group of rare diseases is characterized by chronic muscle inflammation leading to muscle weakness. The term "idiopathic" indicates that the exact cause is unknown. These conditions are considered refractory when they do not respond to standard treatments. Over time, individuals may experience increasing difficulty with muscle strength and endurance. The inflammation primarily affects skeletal muscles, which are responsible for movement. Symptoms can vary but often include muscle pain, fatigue, and difficulty performing daily activities.
Trial detailsLast updated 7 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-514137-38-00Protocol codeCYTB323L12201Estimated enrolment111 patientsSponsorNovartis Pharma AG

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