Effectiveness and safety of telitacicept for refractory generalized myasthenia gravis: a retrospective study

Abstract

Background: Refractory generalized myasthenia gravis (GMG) remains a substantial therapeutic challenge. Telitacicept, a recombinant human B-lymphocyte stimulator receptor-antibody fusion protein, holds promise for interrupting the immunopathology of this condition.

Objectives: This study retrospectively assessed the effectiveness and safety of telitacicept in patients with refractory GMG.

Design: A single-center retrospective study.

Methods: Patients with refractory GMG receiving telitacicept (160 mg/week or biweekly) from January to September in 2023 were included. We assessed effectiveness using Myasthenia Gravis Foundation of America post-intervention status (MGFA-PIS), myasthenia gravis treatment status and intensity (MGSTI), quantitative myasthenia gravis (QMG), and MG-activity of daily living (ADL) scores, alongside reductions in prednisone dosage at 3- and 6-month intervals. Safety profiles were also evaluated.

Results: Sixteen patients with MGFA class II-V refractory GMG were included, with eight females and eight males. All patients were followed up for at least 3 months, and 11 patients reached 6 months follow-up. At the 3-month evaluation, 75% (12/16) demonstrated clinical improvement with MGFA-PIS. One patient achieved pharmacological remission, two attained minimal manifestation status, and nine showed functional improvement; three remained unchanged, and one deteriorated. By the 6-month visit, 90.1% (10/11) sustained significant symptomatic improvement. MGSTI scores and prednisone dosages significantly reduced at both follow-ups (p < 0.05). MG-ADL and QMG scores showed marked improvement at 6 months (p < 0.05). The treatment was well tolerated, with no severe adverse events such as allergy or infection reported.

Conclusion: Our exploratory investigation suggests that telitacicept is a feasible and well-tolerated add-on therapy for refractory GMG, offering valuable clinical evidence for this novel treatment option.

Keywords: B lymphocyte; B-cell activating factor; a proliferation-inducing ligand; myasthenia; refractory generalized myasthenia gravis; telitacicept.

Figure 1.

Immunotherapy in refractory generalized myasthenia gravis. (a) Types of immunosuppressive agents previously administered to patients with refractory generalized myasthenia gravis. (b) Prevalence and distribution of immunosuppressive agents used prior to the study commencement. AZA, azathioprine; CTX, cyclophosphamide; GC, glucocorticoid; IL-6R, interleukin-6 receptor inhibitor; IVIG, intravenous immune globulin; MMF, mycophenolate mofetil; MTX, methotrexate; PE, plasma exchange; RTX, rituximab; TAC, tacrolimus.

Figure 2.

Assessment of clinical status using MGFA-PIS post-telitacicept treatment. (a) Improvement in clinical symptoms was observed in 12 out of 16 patients (75%) at the 3-month follow-up mark. Persistent and significant symptom improvement was noted in 10 of 11 patients (90.1%) at the 6-month follow-up, with six patients achieving symptom remission to MMS or PR status. (b) Improvement in muscular weakness was noted across all muscle groups to varying degrees. Notably, extraocular and bulbar muscles exhibited a slower rate of improvement compared to other muscle groups. MGFA-PIS, Myasthenia Gravis Foundation of America post-intervention status; MMS, minimum manifestation status; PR, pharmacologic remission.

Figure 3.

Clinical outcomes following telitacicept treatment in refractory generalized myasthenia gravis. (a) There was a significant decline in median MGSTI scores at the 3-month follow-up (p < 0.05) and at the 6-month visit (p < 0.05). (b) A reduction in daily prednisone dosage was observed in nine patients (56.3%) at the 3-month follow-up (p < 0.001). By the 6-month evaluation, median prednisone dosage had decreased by 38.6% compared to baseline (p < 0.001). (c and d) Baseline mean QMG and MG-ADL scores were 14.44 ± 6.87 and 5.50 ± 2.92, respectively, which significantly decreased to 8.67 ± 4.06 and 1.22 ± 2.28 at the 6-month follow-up (p < 0.05). MG-ADL, myasthenia gravis activity of daily living; MGSTI, myasthenia gravis treatment status and intensity; QMG, quantitative myasthenia gravis.