Dose escalation and switching patterns of anti-TNF drugs in rheumatoid arthritis: a retrospective chart - review study in Turkey

Abstract

Background There is not enough data on the dosing patterns and switching rates of the most frequently used TNFis infliximab, adalimumab and etanercept in Turkey. Objectives The aim of this retrospective chart review is to compare the proportion of rheumatoid arthritis (RA) subjects requiring treatment modification between the TNFis (etanercept, infliximab and adalimumab). Methods Inclusion criterias; a) Consecutive patients diagnosed with RA who were newly started on TNFis as the first biologic treatment. b) Have received continuous treatment with the index TNFi (the date of initial prescription of a TNFi is considered index date and the TNFi itself is the index TNFi) for at least 3 months following the index date and with a biologic (either the index drug or other biologic to which he/she was switched due to inefficacy) for at least 18 months. DMARDs and corticosteroids doses, dosing regimens and reasons for dose changes collected for 18 months following the index date. The primary end point is the proportion of patients with treatment modification which is defined as either one of the following: The first occurrence of any upward adjustment in dose or dosing frequency of each TNFi from the label/indicated dose and unit of time (etanercept 25 milligram [mg] biweekly or 50 mg once weekly, adalimumab 40 mg once every other week or infliximab 3mg/kilogram [kg] every 8 weeks after the 3rd infusion) within the 12 month period following index date. The first occurrence of any switch to another biologic agent due to inefficacy or loss of efficacy Results Overall 400 patients (79.3% female) were enrolled to this study. TNFi drugs were etanercept (240 patients), adalimumab (80 patients) and infliximab (80 patients) respectively. Mean age was 53±12 years old, mean disease duration was 11.3±7.5 years. Anti-CCP antibody was positive at 115/201 (57.2%), and rheumatoid factor was positive at 178/311 (57.2%) of patients. Baseline DAS-28 score was 5.75±0.79, baseline ESR and CRP were 45±26 mm/hour and 3.4±2.8 mg/dl, respectively. The distribution of modifications such as change of TNFi duration or dosage (modification 1), change of TNFi due to inefficacy or lost of efficacy (modification 2), increase of DMARDs or steroid dosage (modification 3) and add of DMARDs or steroid (modification 4) were shown at table 1. Conclusions Dose escalation was prominent at infliximab than other anti-TNF drugs. Patients with infliximab also had more frequent switch of TNFi due to inefficacy or loss of efficacy. However, increase or add of DMARD or steroid were similar at whole anti-TNF drugs.