Study on the Safety and Effects of YTB323 and Drug Combination for Patients with Treatment-Resistant Generalized Myasthenia Gravis

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What is this study about?

This clinical trial is focused on studying a condition called treatment-resistant generalized myasthenia gravis (gMG). This is a chronic autoimmune disease where the body’s immune system mistakenly attacks the connections between nerves and muscles, leading to muscle weakness. The study is testing a new treatment called YTB323, which is a type of cell therapy. This treatment involves using a patient’s own immune cells, which are modified to better fight the disease, and then infused back into the patient.

The purpose of the study is to assess the safety of YTB323 in patients with gMG who have antibodies against specific proteins called AChR or MuSK. The study will also look at how the treatment affects the body over time. Participants will receive the treatment through an infusion, which is a way of delivering medication directly into the bloodstream. The study will monitor participants for any side effects and changes in their health, including vital signs and laboratory tests.

In addition to YTB323, the study involves other medications such as Fludarabine Phosphate, Tocilizumab, Cyclophosphamide, and Flebogamma DIF, which are used to prepare the body for the main treatment or manage symptoms. The study will take place over several years, with regular check-ups to track the progress and effects of the treatment. Participants will be closely monitored to ensure their safety and to gather information on how well the treatment works in managing the symptoms of gMG.

1 initial assessment

Upon joining the study, an initial assessment is conducted to confirm eligibility. This includes reviewing medical history and conducting necessary tests to ensure adequate renal, hepatic, cardiac, hematological, and pulmonary function.

A confirmed diagnosis of treatment-resistant generalized myasthenia gravis (gMG) with positive antibodies against AChR or MuSK is required.

2 pre-treatment phase

Participants may need to adjust current medications, such as tapering corticosteroids to a maximum dose at least one week before leukapheresis.

Leukapheresis is a procedure to collect white blood cells, which is necessary for the preparation of the study treatment.

3 conditioning regimen

Participants receive a conditioning regimen to prepare the body for the study treatment. This includes the administration of fludarabine phosphate and cyclophosphamide via IV infusion.

4 administration of study treatment

The study treatment, YTB323, is administered through intravenous use. This is a key part of the study aimed at assessing the safety and efficacy of the treatment.

5 monitoring and follow-up

Participants are closely monitored for any adverse events, including changes in vital signs, laboratory parameters, ECG, and neurological status.

Regular assessments are conducted to measure the levels of YTB323 in the blood and to evaluate the immune response to the treatment.

6 supportive care

Supportive care may include the administration of tocilizumab and human normal immunoglobulin (IV) as a solution for infusion to manage potential side effects and support the immune system.

7 evaluation of outcomes

The effectiveness of the treatment is evaluated by measuring changes in the MG-ADL score and QMG total score over time.

The study aims to determine if participants achieve a significant reduction in symptoms and maintain this improvement for six months.

Who Can Join the Study?

  • Must have signed an informed consent form and be able to communicate well with the study doctor and follow the study requirements.
  • Must be a male or female between 18 and 65 years old with good kidney, liver, heart, blood, and lung function.
  • Must have a confirmed diagnosis of generalized myasthenia gravis (gMG), which is a condition that affects the muscles, with positive antibodies against AChR (acetylcholine receptor) or MuSK (muscle-specific kinase) at the start of the study. Additionally, must have one of the following: a history of abnormal muscle tests, a positive test for acetylcholinesterase (a substance that helps muscles work), or improvement in muscle weakness with an oral acetylcholinesterase inhibitor as judged by the doctor.
  • Must have generalized myasthenia gravis classified as MGFA Class III-IVa, which indicates a certain level of muscle weakness, at the start of the study.
  • Must have treatment-resistant gMG, meaning the condition does not improve with standard treatments. This is defined by a MG-ADL score of 6 or higher, which measures daily life activities, despite trying at least two different non-steroidal immunosuppressive drugs. Must have failed treatment with at least one oral immunomodulatory or steroid-sparing drug and either one approved anti-C5 complement antibody, an approved FcRn antagonist, or rituximab, or needed two or more rescue therapies like plasma exchange or IVIg for worsening symptoms in the past year.
  • If taking long-term corticosteroids, must be able and willing to reduce the dose to a certain level at least one week before a procedure called leukapheresis, which involves removing white blood cells from the blood.

Who Cannot Join the Study?

  • Patients who do not have treatment-resistant generalized Myasthenia Gravis cannot participate. This means the study is only for those whose condition does not improve with standard treatments.
  • Patients without antibodies against AChR (acetylcholine receptor) or MuSK (muscle-specific kinase) are excluded. These are specific proteins related to the condition.
  • Patients who are not within the specified age range for the study cannot participate. The study is for adults only.
  • Patients who are not part of the specified clinical trial group are excluded. This means the study is for a specific group of patients with certain characteristics.
  • Patients who are not male or female are excluded, as the study includes both genders.
  • Patients who are not considered part of a vulnerable population are excluded. This refers to groups that may need special protection in research.

Where you can join this trial?

Verified and Recommended Sites

No sites found in this category

Verified Sites

Site Name City Country Status
Oncopole Claudius Regaud Toulouse France
Centre Hospitalier Universitaire De Bordeaux Bordeaux France
Centre Hospitalier Universitaire De Lille Lille France
Centre Hospitalier Regional Et Universitaire De Brest Brest France

Other Sites

No sites found in this category

Want to learn more about this study or check if you can participate? Contact us.

Trial status

Country Status Recruitment Start
France France
Recruiting
01.03.2025

Trial locations

YTB323 is an investigational therapy being studied for its safety and effectiveness in patients with treatment-resistant generalized myasthenia gravis. This condition is characterized by muscle weakness and fatigue due to the body’s immune system attacking its own muscle receptors. YTB323 is designed to help manage these symptoms in patients who have not responded well to other treatments. The study aims to understand how this therapy works in the body and its potential benefits for patients with this challenging condition.

Investigated diseases:

Myasthenia Gravis – Myasthenia Gravis is a chronic autoimmune disorder that affects the communication between nerves and muscles, leading to muscle weakness. It occurs when the immune system mistakenly attacks the connections between nerves and muscles, specifically targeting receptors that receive nerve signals. This results in symptoms such as drooping eyelids, difficulty swallowing, and general muscle fatigue. The severity of muscle weakness can vary, often worsening with activity and improving with rest. In treatment-resistant generalized Myasthenia Gravis, standard therapies are ineffective, and symptoms persist despite treatment efforts. The condition can significantly impact daily activities and quality of life.

Trial ID:
2024-513589-20-00
Protocol code:
CYTB323O12101
Trial Phase:
Human Pharmacology (Phase I) – Other

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