Effectiveness and safety of infliximab dose escalation in patients with refractory Takayasu arteritis: A real-life experience from a monocentric cohort.

Objectives: To evaluate effectiveness and safety of infliximab dose escalation in Takayasu arteritis (TAK) patients. To identify factors associated with refractoriness to standard-dose infliximab.

Methods: Medical records of infliximab-treated TAK patients from a large single-centre observational cohort were reviewed. Infliximab therapy duration, concomitant therapies, and reasons for dose escalation and therapy suspension were evaluated. Occurrence of adverse events was recorded. A comparison between patients who maintained infliximab standard-dose and those who needed dose-escalation was performed. Factors associated with refractoriness to standard dose were analysed.

Results: Forty-one patients were included. Starting infliximab dose was 5 mg/kg 6-weekly and 28 patients (68%) needed dose escalation. Persistence/recurrence of clinical symptoms was the most frequent reason for escalation. Median therapy duration was 39 (IQR, 26-61) months in the standard-dose group and 68 (38-87) months in the intensified-dose group. In the intensified-dose-group, infliximab was suspended in eight patients (29%) after a median of 38 (31-71) months, due to loss of response (n = 7) or patient's request (n = 1). Patients in the intensified-dose group had a higher number of relapses (3.4 vs 0.8 events/patient) and received a higher cumulative steroid dose (1.7 [1.6-2.3] vs 1.3 [1-1.6] g/month of prednisone). Three patients from the intensified-dose group had serious infections; one patient from the standard-dose group developed paradoxical psoriasis. At univariate analysis, age at diagnosis and age at infliximab start were associated with infliximab escalation.

Conclusion: In TAK, dose escalation is safe and allows to optimise infliximab durability in refractory patients. Younger patients seem to be more refractory to standard dosages.