Down-Titration of Infliximab:The Real-Life Use in Psoriatic Patients

The anti-tumor necrosis factor (anti-TNF) drugs have allowed a complete and rapid remission in patients with moderate to severe psoriasis, but these drugs are often associated to dose-dependent adverse effects and high costs.¹ For this reason, the down-titration (dose reduction, discontinuation and disease activity guided dose tapering) of the available anti-TNF agents has become recently more and more common for the patients with a low disease activity, particularly in rheumatology.¹ Although in dermatology this practice has not been investigated yet, it is already used by several Psoriasis Centres in Italy. Infliximab, one of the most used anti-TNF agents, is a monoclonal antibody that is administered intravenously at a dose of 5 mg/kg at the baseline, then after 2 and 6 weeks and nally every 8 weeks. Due to its administration methods, requiring a frequent hospitalization, infliximab may have a high impact on patient’s quality of life and important overall costs.¹ Thus, the down-titration of infliximab, particularly prolonging the dose intervals (10 weeks instead of 8 weeks), has already been performed for several years in clinical practice. Therefore, we decided to perform a retrospective study, aiming to establish if the elongation of dose intervals is associated with a higher rate of psoriasis relapses and could be considered a valid treatment method. We reviewed the clinical charts of patients treated with infliximab at the outpatient services of two Italian referral Psoriasis Centres (Division of Dermatology, University of Bologna, Italy and Division of Preventive and Oncological Dermatology, University of Florence, Italy). We included in this retrospective observational study all the patients affected by moderate-severe psoriasis treated with infliximab since May 2005. We divided the patients in two different groups: a group represented by subjects with stable remission of psoriasis (Psoriasis Area and Severity Index score, PASI=0) for at least 12 months at the standard dose (5 mg/kg every 8 weeks), who then received the treatment at prolonged dose intervals (5 mg/kg ev- ery 10 weeks) and the other group including the patients who have reached an improvement of the 90% of their initial PASI (PASI90) and continued the standard administration intervals (5 mg/kg every 8 weeks). For each group, we considered the percentage of relapses, defining a relapse the worsening of the 50% of the initial PASI, along with the duration of the disease, the beginning of the therapy, the PASI before the beginning of the therapy and the main comorbidities (smoking habits, diabetes, psoriatic arthritis). We also calculated the total annual savings, based on the cost of infliximab in Italy at 5mg/kg for an average patient of 70 kg, with the prolonged interval administration. The statistical test between the two groups, as de ned above, was performed using the Welch’s t-test (that assumes unequal sample sizes as well as unequal variances). We therefore used a standard