TNFα blockers followed by continuation of sulfasalazine and methotrexate combination: a retrospective study on cost saving options of treatment in Spondyloarthritis

Abstract

High cost deters continuous use of tumor necrosis factor α blockers (TNFi) in developing countries. The objective of this study was to evaluate outcome and expenditure incurred in Spondyloarthritis (SpA) patients beyond a year of follow-up after receiving four doses of infliximab (IFX) over and above background therapy of methotrexate (MTX) and sulfasalazine (SSZ) combination. Electronic medical records were screened for patients with SpA satisfying the Assessment of Spondyloarthritis International Society (ASAS) criteria between 2008 and 2014. Patients who completed at least 1 year of follow-up after receiving four doses of IFX (5 mg/kg at 0, 2, 6, and 14 weeks) on a background therapy of MTX (10-25 mg/week) and SSZ (2-3 g/day) combination were enrolled after obtaining an informed consent. Primary outcome assessed was "time to disease flare". Changes in acute phase reactants, patient reported outcomes (BASDAI, BASFI), and cost were also assessed. Forty-five patients were enrolled. Mean (SD) duration of follow up after fourth IFX dose was 28.9 (18.7) months. Disease flare occurred in 33.3% (15/45) after a mean (SD) duration of 14.5 (10.8) months as compared to 4-6 months described in literature on discontinuing TNFi. Reduction in ESR, CRP, BASDAI and BASFI continued to be statistically significant at follow-up as compared to baseline. As compared to continuous IFX therapy, this treatment reduced cost by 57.1% for each patient-month of follow-up. Short course IFX dosing followed by continuation of MTX and SSZ combination can prolong time to disease flare and decrease requirement for additional IFX dose in SpA. This regimen could be a cost saving option for patients with SpA.

Keywords: Infliximab; Methotrexate; Seronegative spondyloarthritis; Sulfasalazine; TNFα blockers.