Objectives
To describe patterns of treatment observed in the first two years after diagnosis in a real-world population of adult myasthenia gravis (MG) patients.
Methods
We identified patients with ≥ 1 inpatient or ≥ 2 outpatient diagnoses of MG in Optum’s De-Identified Clinformatics® Data Mart Database. Patients were required to be ≥ 18 years and have continuous observation for ≥ 365 days before and 730 days after the initial MG diagnosis. Treatments of interest included acetylcholinesterase inhibitors (AChEIs), oral corticosteroids (OCs), steroid-sparing immunosuppressants (NSISTs: azathioprine, cyclosporine, cyclophosphamide, methotrexate, mycophenolate mofetil, and tacrolimus), monoclonal antibodies (MABs: rituximab, eculizumab), and rapid-acting immunosuppressants (RAIs: intravenous or subcutaneous immunoglobulins & plasmapheresis or plasma exchange). We also conducted sensitivity analyses in the Optum Pan-Therapeutic Electronic Health Records (Panther EHR) Database.
Results
7,768 MG patients (average age 66 years, 51% female) met inclusion criteria. Of these, 5,535 patients (72%) received any treatment during the 730 days following diagnosis. Among treated patients, 54% went onto a second type of therapy, 32% to a third, and 17% to a fourth or more. The most common first therapy was AChEIs (45%), followed by OCs (33%), and their combination (8%). Use of NSISTs was not common until the third received therapy. RAIs and MABs were used in up to 20% and 3% of patients, respectively, depending on order of receipt. Patients diagnosed by a neurologist within 365 days of initial diagnosis had a higher overall treatment prevalence (79%). Sensitivity analyses in Panther-EHR revealed similar patterns, with higher overall treatment prevalence (81% total, 89% among those diagnosed by a neurologist).
Conclusions
A minority of real-world MG patients remain untreated in the first 730 days after diagnosis. Differences in this proportion across data sources suggest the possibility of primary nonadherence: patients receiving but not filling prescriptions. A substantial proportion of patients trialing many therapies within a short period after diagnosis suggests high unmet need remains in MG.