Longitudinal treatment patterns in myasthenia gravis: An analysis from the prospective Dutch-Belgian patient registry

Background: Understanding treatment patterns in myasthenia gravis (MG) is crucial for clinical practice. However, longitudinal data are limited. Objective: This study aimed to provide an overview of treatment patterns in different subgroups throughout the disease course. Methods: All adult patients with acetylcholine receptor (AChR), muscle-specific kinase (MuSK), or seronegative MG enrolled in the Dutch-Belgian myasthenia registry were included. AChR-MG patients were classified into early-onset (EOMG) (≤50 years) and late-onset (LOMG) (>50 years) MG. Mixed-effects regression was used to compare differences between the different subgroups. Results: A total of 506 patients were included (147 AChR EOMG, 265 AChR LOMG, 26 MuSK, and 94 seronegative MG patients). Data were available within a year of diagnosis for 84 patients. Most patients initially started treatment with pyridostigmine (93%; 78/84), followed by corticosteroids (52%; 44/84) and azathioprine or mycophenolate mofetil (30%; 25/84). After ten years, the use of pyridostigmine (65%; 54/83) and corticosteroid use (36%; 30/83) declined, whereas the use of azathioprine and mycophenolate mofetil increased (55%; 46/83). Seronegative patients received fewer treatments than AChR MG patients, independent of functional status and disease duration (OR 0.38, 95% CI 0.17–0.84, p = 0.018), and were less likely to use corticosteroids (OR 0.15, 95% CI 0.05–0.41, p < 0.001). Patients with LOMG reported more frequently immunosuppressive use compared to patients with EOMG (OR 4.69, 95% CI 1.16–19.02, p = 0.031). Conclusions: This analysis offers valuable insights into treatment patterns in different subgroups of patients with MG. A substantial proportion of patients continues to rely on corticosteroids, suggesting an ongoing need for alternative treatment options.