The safety of rituximab biosimilar GP2013 was comparable with that of the rituximab reference biologic and no additional safety risks were identified for patients with rheumatoid arthritis (RA), according to results from a study published in Arthritis Care & Research.
Researchers conducted a multicenter, randomized, double-blind, parallel-group study investigating the safety implications of switching from reference rituximab to biosimilar GP2013, compared with continuing reference rituximab therapy, in patients with RA. Both study groups were given methotrexate and folic acid and patients were randomly assigned to receive either the biosimilar or remain on reference rituximab. Investigators assessed immunogenicity, infusion-related and hypersensitivity reactions, and overall safety in both groups.
After analysis, investigators found that the incidences of infusion-related (11.3% vs 18.5%) and hypersensitivity reactions (9.4% vs 11.1%) were comparably low in both the biosimilar and reference rituximab groups, respectively. With respect to immunogenicity, neutralizing antidrug antibodies did not develop in any participants. Furthermore, no clinically relevant differences in adverse events were found between the groups.
The primary study limitation was the lack of statistical power to establish safety equivalence.
“The results of this study demonstrate that treatment switch from reference [rituximab] to the biosimilar GP2013 in RA patients previously treated with [rituximab] as part of routine practice has a comparable safety profile to continuation of reference [rituximab],” the researchers wrote.
Further studies are needed to fully establish statistical safety equivalence between biosimilar GP2013 and reference rituximab.
Tony HP, Kruger K, Cohen S, et al. Safety and immunogenicity of rituximab biosimilar GP2013 after switch from reference rituximab in patients with active rheumatoid arthritis [published online October 8, 2018]. Arthritis Care Res. doi: 10.1002/acr.23771