Treatment Patterns in Patients with Late-Onset Myasthenia Gravis in Japan: An Insurance Claims Database Study

Area of Science:

• Neurology
• Immunology
• Pharmacology

Background:

• Myasthenia gravis (MG) treatment patterns and oral corticosteroid (OCS) use differ between late-onset (≥75 years) and early/adult-onset (<75 years) patient cohorts.
• Understanding these differences is crucial for optimizing MG management.

Purpose of the Study:

• To evaluate and compare treatment patterns, specifically OCS use and early fast-acting treatment (EFT) initiation, in Japanese patients with late-onset versus early/adult-onset myasthenia gravis.
• To analyze treatment frequency rates in these distinct patient groups.

Main Methods:

• A retrospective analysis of the DeSC Healthcare claims database (2014-2021) was performed.
• Adult MG patients initiating immunosuppressant therapy with at least 2 years of follow-up were included and stratified by age (≥75 vs <75 years) and EFT exposure.
• Outcomes included OCS dose trajectories, time to reach a ≤5 mg/day maintenance dose, and treated MG case frequency.

Main Results:

• Late-onset patients were less likely to receive EFT (20.9% vs 28.0%).
• Initial/maximum OCS doses and time spent above 20 mg/day were generally lower in the late-onset cohort.
• Late-onset patients achieved the OCS maintenance target more often and sooner (median 5.1 vs 14.9 months), especially without EFT.
• The frequency of treated MG cases was higher in the late-onset group (7.09 vs 3.97 per 100,000).

Conclusions:

• Late-onset MG patients received less EFT but achieved lower OCS doses and reached maintenance targets earlier, possibly due to physician caution and effective treatment response.
• Findings emphasize the need for timely EFT identification, OCS-sparing strategies, and clearer clinical guidance for late-onset MG patients.