Tofacitinib for the treatment of recurrent IgG4-related disease: clinical experience in 7 patients.

OBJECTIVES: This observational study aimed to evaluate the efficacy and safety of the Janus kinase (JAK) inhibitor tofacitinib in the management of recurrent IgG4-related disease (IgG4-RD). METHODS: Seven patients admitted to the Rheumatology Department of Peking University People's Hospital were enrolled. All patients met the 2019 American College of Rheumatology (ACR) / European League Against Rheumatism (EULAR) classification criteria for IgG4-RD. Disease recurrence was defined as relapse of previously affected organs or involvement of new organs, accompanied by an IgG4-RD Responder Index (IgG4-RD RI) score ≥2 in any item, with or without re-elevation of serum IgG4 levels. Patients were initiated on tofacitinib 5 mg twice daily, with a concurrent increase in glucocorticoids (GCs) dosage not exceeding 10 mg (prednisone equivalent), concomitant immunosuppressants were either continued or discontinued. Clinical data were recorded at baseline, 1 month, 3 months, and every 3 months thereafter. Disease response was assessed using the IgG4-RD RI, physician global assessment (PGA) and serum IgG4 levels. Treatment responses were categorised as complete response (CR), partial response (PR), or relapse. RESULTS: Patients were aged 33-70 years (mean disease duration, 45 months, range 18-84 months). Six patients achieved CR, while one experienced relapse. Tofacitinib treatment for 1, 3, and 6 months resulted in a reduction in both IgG4-RD RI scores (p=0.017, p=0.018, p=0.043, respectively) and PGA scores (p=0.017, p=0.018, p=0.042, respectively). Serum IgG4 levels decreased at 3 months (p=0.028) and 6 months (p=0.043). Within 6 months of initiating tofacitinib, four out of seven patients reduced their GC dosage to ≤5 mg/day (prednisone equivalent), and two discontinued GCs during follow-up. Tofacitinib was well tolerated. Only one patient developed mild herpes zoster, and no serious adverse events were reported. CONCLUSIONS: Tofacitinib is effective and safe for the management of recurrent IgG4-RD, with the additional benefit of reducing GC dependence.