Disease-Modifying Treatments for Myasthenia Gravis

Design & procedures - This is an observational study in the real world clinical setting to
evaluate immunosuppressive treatment (IS) of myasthenia gravis (MG). Patients with acquired
autoimmune MG ≥ 18 years of age who are not on IS agents, and have not been on
corticosteroids for at least 30 days will be enrolled at 20 sites in the US and Canada. These
patients will be treated according to the physician's judgment and patient preferences as in
routine clinical practice. Patients will be followed prospectively, with the frequency of
clinical visits and laboratory monitoring determined by the treating physician, which may
differ among patients. Standard outcome measures measuring efficacy and adverse effects that
are used in clinical practice will be collected, with emphasis on patient reported outcomes.
Informed consent will be obtained using an approved consent form. Patient identifiable /
clinical information from the medical record, including the study outcome measures will be
uploaded to a centralized REDCap database. The investigators plan to recruit 220 patients,
adjusting for a 10% drop out rate, with a final sample of 200 patients for analysis.

Inclusion Criteria:

Participants eligible for inclusion in this study must fulfill all of the following
criteria:

1. Age ≥ 18 years of age

2. Acquired autoimmune MG, with weakness and confirmed by one or more of the following:

1. Elevated AChR or MuSK antibodies

2. Unequivocal response to cholinesterase inhibitors

3. Abnormal RNS or increased jitter (without nerve or muscle disease sufficient to
produce a decrement or increased jitter)

3. Patients seen initially at the participating center after January 1, 2017.

4. Patients on pyridostigmine at the first evaluation at the participating center
("baseline visit") may be included if pyridostigmine was started ≤3 months before the
baseline visit.

5. Patients who received corticosteroids >90 days prior to baseline visit for a non-MG
indication may be included. (Patients who have received corticosteroids for a non-MG
indication between 31 and 90 days before baseline visit will be evaluated by the
primary investigators on a case by case basis to determine if the extent and dose of
corticosteroid could have impacted the course of MG or symptoms of MG.)

Exclusion Criteria:

Patients fulfilling any of the following criteria are not eligible for inclusion in this
study. No additional exclusions may be applied by the investigator, in order to ensure that
the study population will be representative of all eligible participants.

1. Patients with non-autoimmune MG (congenital myasthenic syndromes, drug-induced MG)

2. Patients on immunosuppressive agents at the baseline visit.

3. Patients who have previously received steroids for the treatment of MG.

4. Patients with steroid use for a non-MG indication < 30 days prior to the baseline
visit.

5. Patients with previous thymectomy, IVIg or plasma exchange, or treatment with a
non-steroidal immunosuppressive agent (azathioprine, mycophenolate mofetil
cyclosporine, methotrexate, cyclophosphamide, tacrolimus, rituximab, or any
investigational immunosuppressive agent). Patients who have outcomes measured within
24 hours after initiation of IVIg or PLEX are acceptable.