Ofatumumab Treatment for Refractory Generalized Myasthenia Gravis Post‐Lung Adenocarcinoma Resection: A Case Report and Mechanistic Insight
Xia Long, Yanwen Xu, Juan Xiong, Wenfeng Peng, Jinhua Qiu, Yanxia ZhouABSTRACT
Background
Myasthenia gravis (MG), an autoimmune neuromuscular disorder, may rarely coexist with malignancies such as lung cancer.
Case Presentation
This case report presents the first documented use of ofatumumab, a fully human anti‐CD20 monoclonal antibody, in a 75‐year‐old female with acetylcholine receptor (AChR)‐antibody‐positive generalized MG (gMG) following lung adenocarcinoma resection. Initially diagnosed with ocular MG (MGFA Class I), the patient progressed to refractory gMG (MGFA Class IIIa) post‐thymectomy and tumor resection, unresponsive to corticosteroids, tacrolimus, and intravenous immunoglobulin. Due to persistent symptoms and steroid‐induced complications, subcutaneous ofatumumab (20 mg on Days 1, 7, and 14) was administered off‐label. Rapid clinical improvement was observed, with Myasthenia Gravis Composite (MGC) and MG Activities of Daily Living (MG‐ADL) scores declining from 20 to 10 and 17 to 10, respectively, within weeks. Minimal manifestation status (MMS) was sustained for 2 years with intermittent ofatumumab re‐administration (triggered by CD19/CD20 + B‐cell reconstitution > 1%), alongside no tumor recurrence or adverse events.
Conclusion
This case highlights ofatumumab's potential efficacy and safety in managing refractory gMG post‐cancer resection, possibly via robust B‐cell depletion and reduced immunogenicity. These findings advocate for targeted B‐cell therapies as a viable strategy in complex, refractory MG cases, particularly where conventional immunosuppressants pose oncological concerns.