Sarilumab (a human monoclonal antibody) has been known to offer consistent effectiveness over a period of 5 years in patients who had unmanagable rheumatoid arthritis (RA) with the TNF inhibitors, as concluded from a study by Roy Fleischmann et al.

RA patients in the 24-week TARGET trial who received placebo or sarilumab 150 or 200 mg every 14 days, along with conventional synthetic DMARDs (csDMARDs), were suitable to obtain a combination of sarilumab 200 mg every 14 days and csDMARDs in the long-term extension study (OLE). Decrease of OLE dose to 150 mg every 2 weeks was in accordance with the judgment by study investigators or protocol-mandated safety concerns.

OLE study had 454 (83%) out of 546 patients on sarilumab therapy. The cumulative study period was 1654.8 patient-years and 268 patients (51%) had an exposure of more than equal to 4 years'. Incidence rates per 100 PY of adverse effects (AEs) was 160.4, discontinuation due to AEs was 8.1 and infection was 57.8. The most frequently observed AE was neutropenia. Seventy four patients (14.2%) had total neutrophil count <1000 cells/mm3 and which was controlled in 48 patients on sarilumab therapy. A follow-up of 5 years depicted a sustained clinical efficacy. Similar efficacy was witnessed in patients who had TNFi failure, and between patients who either continued 200 mg or decreased to 150 mg.