Effects of Fostamatinib (R788), an Oral Spleen Tyrosine Kinase Inhibitor, on Health-related Quality of Life in Patients with Active Rheumatoid Arthritis: Analyses of Patient-reported Outcomes from a Randomized, Double-blind, Placebo-controlled Trial

Abstract

OBJECTIVE: To assess the influence of fostamatinib on patient-reported outcomes (PRO) in patients with active rheumatoid arthritis and an inadequate response to methotrexate (MTX). METHODS: Patients taking background MTX (N = 457) were enrolled in a phase II clinical trial (NCT00665925) and randomized equally to placebo, fostamatinib 100 mg twice daily (bid), or fostamatinib 150 mg once daily (qd) for 24 weeks. Self-administered PRO measures included pain, patient's global assessment (PtGA) of disease activity, physical function, health-related quality of life (HRQOL), and fatigue. Mean change from baseline and a responder analysis of the proportion of patients achieving a minimal clinically important difference were determined. RESULTS: At Week 24, there were statistically significant improvements in pain, PtGA, physical function, fatigue, and the physical component summary of the Medical Outcomes Study Short Form-36 (SF-36) for fostamatinib 100 mg bid compared with placebo. Mean (standard error) changes from baseline in the fostamatinib 100 mg bid group versus the placebo group were -31.3 (2.45) versus -17.8 (2.45), p < 0.001 for pain; -29.1 (2.26) versus -16.7 (2.42), p < 0.001 for PtGA; -0.647 (0.064) versus -0.343 (0.062), p < 0.001 for physical function; 7.40 (1.00) versus 4.50 (0.94), p < 0.05 for fatigue; 8.52 (0.77) versus 4.90 (0.78), p < 0.01 for SF-36 physical component score; and 3.99 (0.93) versus 3.71 (0.99), p = 0.83 for SF-36 mental component score. Patients receiving fostamatinib 150 mg qd showed improvements in some PRO, including physical function. CONCLUSION: Patients treated with fostamatinib 100 mg bid showed significant improvements in HRQOL outcomes.