Winthrop KL, et al. - Whether rituximab has long-term safety in patients with rheumatoid arthritis (RA) with an inadequate response to ≥1 anti–tumor necrosis factor therapy, was assessed in this prospective, observational cohort study in the US (SUNSTONE [Study of the Safety of Rituxan in Patients With Rheumatoid Arthritis After an Inadequate Response to Previous Anti-TNF Therapy] registry). The incidence of protocol-defined significant infections was assessed in the safety-evaluable population including 989 patients who were administered ≥1 dose of rituximab. Researchers reported 341 significant infections in 197 patients (19.9%). For significant infections, cardiovascular or thrombotic events, and seizures, the estimated incidence rates were 8.87, 1.95, and 0.18 per 100 patient-years, respectively. Infections, malignancy, and cardiovascular events were documented as the most common reasons for mortality. Findings revealed stable rates of significant infections over time in RA patients who received rituximab for up to 5 years. Those treated with long-term systemic steroid therapy had higher rates.