FRI0161 Sustained Efficacy and Comparable Safety and Immunogenicity after Transition To SB5 (An Adalimumab Biosimilar) vs Continuation of The Adalimumab Reference Product in Patients with Rheumatoid Arthritis: Result of Phase III Study

Background SB5 is a biologic agent developed as a biosimilar of the adalimumab reference product (ADL). The 24-week results of Phase III study results have been reported 1 . Objectives To evaluate the efficacy, safety, and immunogenicity in patients with RA who transitioned from ADL to SB5 vs. patients who maintained ADL and patients who continued to receive SB5 during the transition period after Week 24 up to Week 52. Methods Patients with RA were randomised in a 1:1 ratio to receive either SB5 or ADL 40 mg every other week (EOW) via subcutaneous injection. At Week 24, patients receiving ADL were re-randomised in a 1:1 ratio to either be transitioned to SB5 or continue on ADL EOW up to Week 50. Patients receiving SB5 continued to receive SB5 but they also followed the randomisation procedure to maintain blinding. Efficacy, safety, and immunogenicity were assessed up to Week 52. Results At Week 24, 254 patients from SB5 continued to receive SB5 (SB5/SB5), 125 patients from ADL were transitioned to SB5 (ADL/SB5), and the 129 patients from ADL continued to receive ADL (ADL/ADL). The ACR responses at Week 52 in per-protocol set were comparable between SB5/SB5, ADL/SB5, and ADL/ADL (76.9% vs 81.1% vs 71.2% for ACR20, respectively). Other efficacy endpoints were also comparable across the treatment groups. The change of modified total Sharp score was comparable with mean change of 0.17 in SB5/SB5 vs 0.25 in ADL/SB5 vs 0.50 in ADL/ADL. The safety profile during the transition period was comparable. Two patients newly reported injection site reactions only in ADL/ADL. The incidence of anti-drug antibody was 15.7% in SB5/SB5, 16.8% in ADL/SB5, and 18.3% in ADL/ADL during the transition period. Conclusions During the transition period after Week 24 up to Week 52, the efficacy, safety, and immunogenicity profiles were comparable between SB5/SB5, ADL/SB5, and ADL/ADL. There were no treatment emergent issues or clinically relevant immunogenicity precipitated by switching. References Weinblatt ME et al. Arthritis Rheumatol. 2015; 67 (suppl 10), 8L Disclosure of Interest M. Weinblatt Consultant for: AbbVie, Samsung Bioepis, Amgen, A. Baranauskaite Grant/research support from: AbbVie, Samsung Bioepis, J. Niebrzydowski Grant/research support from: Samsung Bioepis, E. Dokoupilova Grant/research support from: Samsung Bioepis, A. Zielinska Grant/research support from: Samsung Bioepis, K. Sitek-Ziolkowska Grant/research support from: Samsung Bioepis, J. Jaworski Grant/research support from: Samsung Bioepis, A. Racewicz Grant/research support from: Samsung Bioepis, M. Pileckyte Grant/research support from: Samsung Bioepis, K. Jedrychowicz-Rosiak Grant/research support from: Samsung Bioepis, V. Zhdan Grant/research support from: Samsung Bioepis, S. Y. Cheong Employee of: Samsung Bioepis, J. Ghil Employee of: Samsung Bioepis