Reports to-date indicate similarity between infliximab biosimilar (IB) and infliximab bio-original (IO) in clinical efficacy and safety. This study examines the survival of IB and IO using routinely collected data over a 2-year period.
Routinely collected clinical data inputted directly in an electronic database at a large rheumatology centre were analysed. Adult patients taking IO or IB for any rheumatological diagnosis were included. Kaplan-Meier survival analyses were used to examine IB and IO survival, with a sub-group analysis among those starting infliximab from 2008 onwards.
Out of 395 patients analysed, 53% (n=209) were female; the majority had rheumatoid arthritis (31%) followed by spondyloarthritis (28%). Ninety-nine patients had IB as the first infliximab drug. Patients who started on IB vs. IO as their first infliximab product, had better survival over the first 2 years (log rank=0.001). Discontinuation due to inefficacy was much commoner in IO versus IB users (18 vs. 5%). In patients switching from IO to IB, drug survival was better versus those receiving IB as the first infliximab drug (log rank=0.073).
IB was well-tolerated and comparable to IO, with no additional safety signals identified. The results suggest superior survival of IB over IO over the first 2 years.