Generalized Myasthenia Gravis (gMG) is a rare autoimmune disease (a disease in which the body attacks its own tissues) that causes muscle weakness and significant fatigue.

Current treatments (corticosteroids, plasma exchange, intravenous immunoglobulin infusions) improve symptoms in many patients. However, many continue to suffer from fatigue and fatigability that are not well measured by standard tools. Moreover, these treatments can cause significant long-term side effects, reducing quality of life.

New treatments such as Rozanolixizumab (ROZ) are now available. They act rapidly and are well tolerated, allowing better symptom control while reducing the risks associated with conventional treatments.

To properly evaluate these new treatments, it is essential to understand patients' perspectives on their effectiveness. The scales used by physicians do not always capture all the symptoms experienced by patients, particularly fatigability. This is why a new tool has been developed: the MG symptoms PRO. This questionnaire allows patients to assess their own symptoms (fatigue, weakness of the eyes, mouth, breathing, muscle fatigability) in detail.

This research aims to better understand the effectiveness of treatments from the patients' perspective in order to improve their care.

The goal of the study is to evaluate the impact of Rozanolixizumab administration in real-world practice through the MG symptoms PRO questionnaire. This is an observational study, meaning that the medication is prescribed by the physician according to current regulations, and the study simply collects routine medical data during your follow-up, over a period of approximately 9 months.

Inclusion Criteria:

• Male or female subjects aged ≥18 years;
• Diagnosed with MG with confirmed documentation and supported by a physical exam and confirmed seropositivity for anti AChR or anti MUSK antibodies;
• Meets the clinical criteria as defined by the Myasthenia Gravis Foundation of America (MFGA) for generalized MG class IIa, IIb, IIIa, and IIIb;
• Patient suitable for ROZ treatment (IgG ≥ 5,5 g/l);
• Patient naïve for ROZ treatment, or receiving the last dose more than 3 months prior inclusion;
• MG-ADL score ≥ 3 (with ≥ 3 points of non-ocular symptoms);
• Patient must have received all mandatory vaccinations according to local regulations prior to study enrollment;
• Capable of understanding the written informed consent, and providing signed, dated, and witnessed written informed consent;
• Willing and able to comply with scheduled visits, treatment plan, study restrictions, laboratory tests, contraceptive guidelines, and other study procedures;
• Patient affiliated to a European social security system.

Exclusion Criteria:

• Any current mental condition (psychiatric disorder, senility, or dementia) that, in the opinion of the investigator, may affect study compliance or prevent understanding of the aims, investigational procedures, or possible consequences of the study; and/or patient with a Mini-mental State evaluation (MMSE) of <25;
• History of any illness or any clinical condition that, in the opinion of the investigator, might confound the results of the study or pose an additional risk in administering study drug to the subject;
• History of ongoing malignancy (except basal cell and squamous cell carcinomas of the skin, or in situ carcinoma of the cervix uteri that have been completely excised and cured);
• Clinically significant uncontrolled active or chronic bacterial, viral, or fungal infection at inclusion;
• Patient receiving concomitant treatment with rituximab, anti-FcRn, complement inhibitors and/or PLEX;
• Patients discontinued from rituximab without respecting the administration rules of ROZ;
• Patient with end-stage diseases or with a disease that will enable him to be evaluated and/or treated;
• Patients with non-treated active infections;
• Patients with hypersensitivity to the active substance(s) or to any of the excipients, specifically: histidine, histidine hydrochloride monohydrate, proline, polysorbate 80, or water for injections.
• Subject, or close relative of the subject, is the investigator or a sub-investigator, research assistant, pharmacist, study coordinator, or other staff directly involved with the conduct of the study at that site;
• Patient protected by law, under guardianship or curator ship, or not able to participate in a clinical study according to the article L.1121-16 of the French Public Health Code

Patients affected by generalized Myasthenia Gravis with anti-AChR and anti-MUSK and treated with ROZ