In a small, early trial, a new type of cell therapy showed long-lasting benefits for people with generalized myasthenia gravis (MG), even one year after treatment. Descartes-08, a chimeric antigen receptor (CAR) T-cell therapy, led to significant and sustained improvement in MG symptoms following a single six-week course of infusions — and without the need for chemotherapy beforehand.

CAR T-cell therapy is a type of treatment in which a person’s own T cells (a type of immune cell) are collected and modified in a lab to recognize and attack specific proteins on diseased cells. Once returned to the body, these modified T cells seek out and destroy targeted cells, such as those involved in cancer or autoimmune conditions.

CAR T-cell therapy is sometimes paired with chemotherapy, which destroys existing immune cells to help the modified T cells grow and work effectively. However, this step can also lead to side effects like fatigue, low blood counts, and increased infection risk. Descartes-08 represents a newer approach to CAR T-cell therapy that doesn’t require chemotherapy.

In the phase 2 study, participants received six weekly outpatient infusions of Descartes-08 without chemotherapy. Researchers reported that more than 80 percent of participants had clinically meaningful improvements — defined as at least a two-point reduction in MG Activities of Daily Living (MG-ADL) scores — one year after treatment. Nearly 1 in 3 reached “minimum symptom expression,” meaning they experienced very few symptoms or none at all.

Side effects were minimal. The most common included fever, chills, headache, and nausea. No serious complications were reported.

Notably, this was a small trial involving 36 participants, with half receiving the therapy while the others received a placebo (inactive treatment).

Promising Early Results Without Chemotherapy

Depending on how Descartes-08 performs in later-phase trials, it could represent a major advance for MG treatment. Current options include immunosuppressants, steroids, and biologics, all of which come with their own potential benefits and side effects. Recruitment for phase 3 trials of the treatment is underway.

If you are managing MG and are curious about new treatments, talk with your neurologist. It may be helpful to ask about emerging therapies and whether there’s a clinical trial that might be right for you.

Learn more about the various treatment options currently available for MG.

Find Your Team

On MGteam, the social network for people living with myasthenia gravis and their loved ones, members come together to ask questions, give advice, and share their stories with others who understand life with MG.

What treatment strategies have helped you manage MG symptoms? Have you talked to your doctor about newer options or research trials? Share your experiences in a comment below, start a conversation on your Activities page, or connect with like-minded members in Groups.