Case report: A highly active refractory myasthenia gravis with treatment of telitacicept combined with efgartigimod

Abstract

There is always a lack of effective treatment for highly active refractory generalized myasthenia gravis (GMG). Recently, telitacicept combined with efgartigimod significantly reduces circulating B cells, plasma cells, and immunoglobulin G, which brings promising therapeutic strategies. We report a case of a 37-year-old female patient with refractory GMG, whose condition got significant improvement and control with this latest treatment after multiple unsuccessful therapies of immunosuppressants. The new combination deserves further attention in the therapeutic application of myasthenia gravis.

Keywords: case report; efgartigimod; highly active; myasthenia gravis; refractory; telitacicept.

Figure 1

Previous therapeutic strategies and the dose of prednisone and pyridostigmine. Each time point represents a MC, which used rapid treatment of IVIg, PLEX, and high-dose steroid (before June 2023). Abbreviations: MC, myasthenic crises; RTX, rituximab; MMF, mycophenolate mofetil; CsA, cyclosporine A; AZA, azathioprine; IVIg, intravenous immunoglobulin; PLEX, plasma exchange. Details: The dose of pyridostigmine was 60 mg ter in die (tid) during 2011 to 2018 and increased to 60 mg quater in die (qid) until June 2023. The prednisone’s dosage was 25 mg qd in August 2018 and declined to 10 mg quaque die (qd) when combining tacrolimus (1.5 mg bid) in September 2019. In February 2020, the patient found an intrauterine pregnancy of 7+ weeks and chose to continue the pregnancy. She discontinued tacrolimus, and the dose of prednisone was increased to 60 mg qd. In July 2020, a segment cesarean section was performed, whose procedure was successful, resulting a live infant. Following discharge, the patient was prescribed tacrolimus of 1 mg bid and prednisone of 70 mg qd. In January 2021, the patient received rituximab treatments on three occasions with doses of 0.1 g d1 and 0.5 g d2 initially, followed by 0.1 g d1 in subsequent two treatments. The prednisone dose was reduced to 40 mg qd after the first treatment and further decreased, respectively, to 30 mg qd and 25 mg qd in September 2021 and January 2022. MMF (1 g bid) was added in September 2022 but discontinued after 18 days. CsA (25 mg bid) was added in November 2022 but, later, discontinued after 14 days. AZA (50 mg qd) was added in March 2023 but discontinued in April 2023 when the fourth rituximab treatment was administered (0.1 g d1). In June 2023, the patient was prescribed telitacicept (160 mg quaque semana (qw)) and added efgartigimod (800 mg qw) in January 2024.

Figure 2

Evolution of clinical severity after injecting telitacicept. (A) Changes in MGFA-QMG, MG-ADL, and MGC. (B) Changes in levels of dose of prednisone and pyridostigmine. Abbreviations: QMG, quantitative myasthenia gravis score; MG-ADL, myasthenia gravis-specific activities of daily living scale; MGC, myasthenia gravis composite; W0, the week before the first injection of telitacicept (June 2024).

Figure 3

Changes in serum marker during follow-up. (A) Changes in immunoglobulin. (B) Changes in lymphocyte. The red point means the time of combination. IgG, immunoglobulin G.