Retrospective evaluation of continuation rates following a switch to subcutaneous methotrexate in rheumatoid arthritis patients failing to respond to or tolerate oral methotrexate: the MENTOR study

Objectives: To retrospectively evaluate continuation rates in patients with rheumatoid arthritis (RA) who failed to respond to or tolerate oral methotrexate (MTX) and were subsequently switched to subcutaneous MTX (SC MTX) in routine clinical practice. Method: We conducted a retrospective review of all patients with RA who had been prescribed SC MTX following oral MTX at the Norfolk and Norwich University Hospital and had been captured on the hospital pharmacy database of MTX use between 17 May 2011 and 20 March 2012. Only patients for whom complete records were available before and for at least 6 months after the switch were included. Results: A total of 196 patients were included in the analysis (75.5% women; mean age at diagnosis 47.4 years; mean duration of oral MTX therapy 6.6 years). Patients were changed from oral to SC MTX because of lack of efficacy (50.5%), adverse events (43.9%), or other/unknown reasons (5.6%). High continuation rates were seen, with 83.0% of patients analysed still on SC MTX at 1 year, 75.2% at 2 years, and 47.0% at 5 years. Following the switch to SC MTX, < 10% of patients were prescribed additional biologic therapy during the first and second year because of an insufficient response. Conclusions: Treatment with SC MTX results in high continuation rates in patients who fail to respond to or tolerate oral MTX. Consequently, management guidelines should be adapted to include advice that SC MTX should be used before biologic therapy and that MTX failure is defined as failure only when use of SC MTX has failed.