Long-term durability and dose escalation patterns in infliximab therapy for psoriasis

Background: Infliximab often requires dose escalation to maintain response. Studies regarding long-term durability and dose escalation patterns for psoriasis are few. Objective: We sought to evaluate dose escalation patterns in psoriatic patients to identify factors of lack of optimal response to infliximab. Methods: A retrospective cohort study included 93 patients (216.3 patient-years) treated with infliximab for psoriasis. Kaplan-Meier analysis assessed drug durability. Results: A median infliximab dose of 5.42 mg/kg/mo (range: 2.71-10.83) for a mean of 28 months was administered. Two thirds of patients received a dose escalation. Concurrent methotrexate extended duration of therapy (by a mean +/- SD of 19.5 +/- 8.1 months, P = .034), including time until first dose escalation (by a mean +/- SD of 12.0 +/- 6.1 months, P = .037), and failure (by a mean +/- SD of 20.7 +/- 6.7 months, P = .034). Patients who increased the infusion frequency before increasing the dose remained on infliximab 8.4 months longer than those who first increased the dose (P = .045). Four patients experienced adverse events; 2 required discontinuation. Limitations: Psoriasis Area and Severity Index, infliximab levels, and antibody titers were not measured. Conclusions: Dose escalation optimizes durability of infliximab. The probability of maintaining response is enhanced by concomitant methotrexate and increasing the infusion frequency before increasing the dose.