To assess the influence of fostamatinib on patient-reported outcomes (PRO) in patients with active rheumatoid arthritis and an inadequate response to methotrexate (MTX).

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.

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.

Patients treated with fostamatinib 100 mg bid showed significant improvements in HRQOL outcomes.