Telitacicept as a New Therapeutic Avenue for Generalized Myasthenia Gravis and Thymoma-Associated Myasthenia Gravis

Generalized myasthenia gravis (gMG) is an antibody mediated autoimmune neuromuscular junction disorder characterized by muscle weakness and fatigue as well as acetylcholine receptor antibody (AChR-Ab) as the main presence. A proportion of patients fail to achieve minimal symptom expression (MSE), furthermore 10-20% of them develop into refractory under conventional immunotherapy. We conducted a retrospective study to explore the effectiveness and safety of telitacicept in gMG and thymoma-associated MG (TAMG) patients. The treatment response was assessed by the variation of QMG, MG-ADL and MG-QOL-15 scores. Time to MSE as well as usage of corticosteroid were also evaluated. In this retrospective study, we included 22 AChR-gMG patients (15 women, 7 men), including 7 refractory and 12 TAMG, who were treated with telitacicept by following-up at least 6 months. Compared to the baseline, a significant decrease in QMG, ADL and MG-QOL-15 scores was observed at every visit, especially for the QMG score with at least 3 points decline in all the patients in week 4. Twenty patients attained MSE and the time to MSE was 4 months during the observed period. At the last follow-up, the dose of prednisone of all the patients treated with telitacicept was ≤ 5 mg/d. The AChR-Ab titers and CD19⁺ B cells significantly decreased from baseline to week 24. Telitacicept is generally well tolerated, the most common (18%) adverse effect was mild and transient injected site swelling. Our study provides evidence to support that telitacicept is beneficial and well tolerated in the management of gMG especially in refractory MG and TAMG. Clinical outcomes showed increased efficacy of telitacicept when used earlier in the disease course, which leads to a sparing of prednisone.