A case of rhupus treated with filgotinib: A promising therapeutic perspective

Rhupus syndrome: Rhupus syndrome, characterized by overlapping clinical features of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), presents significant therapeutic challenges due to its complex pathogenesis and limited treatment options. This case report evaluates the efficacy of filgotinib, a selective JAK1 inhibitor, in a patient with refractory rhupus syndrome. Case presentation: A 42-year-old male, initially diagnosed with SLE in 2013, presented with persistent polyarthritis, cutaneous manifestations, and constitutional symptoms. Conventional treatments including hydroxychloroquine, methotrexate, and belimumab failed to achieve adequate disease control. Diagnosis and treatment: In October 2022, the diagnosis was revised to rhupus based on the evolution of clinical manifestations and laboratory findings, leading to the initiation of filgotinib, a JAK1 inhibitor. Disease activity was monitored over 24 months using standardized assessment tools. Results: Significant clinical improvement was observed within weeks of filgotinib initiation, enabling prednisone dose reduction and maintaining low disease activity throughout the 24-month follow-up period. Conclusion: This case highlights the therapeutic potential of filgotinib in managing rhupus syndrome but further research and larger clinical trials are necessary to establish filgotinib's therapeutic potential and safety profile in the management of SLE.