Objectives: To evaluate the similarities between LBAL (adalimumab biosimilar candidate) and the adalimumab reference product (ADL) in terms of efficacy and safety, including immunogenicity, in patients with active rheumatoid arthritis despite methotrexate treatment.
Methods: This phase III, multicentre, randomised, double-blind, parallel-group, 56-week study was conducted in Japan and Korea. During the first 24 weeks, patients subcutaneously received 40 mg of LBAL or ADL every two weeks (LBAL and ADL groups). During the subsequent 28 weeks, the LBAL group patients and half of the ADL group patients received LBAL (L-L and A-L arms). The remaining ADL group patients continued to receive ADL (A-A arm). The primary efficacy endpoint was the change from baseline in disease activity score 28-erythrocyte sedimentation rate (DAS28-ESR) at Week 24. American College of Rheumatology (ACR) response rates, adverse events (AEs), and anti-drug antibody (ADA) were also assessed.
Results: In total, 383 patients were randomised. The least squares (LS) mean changes from baseline in DAS28-ESR at Week 24 were -2.45 and -2.53 in the LBAL (n=191) and ADL (n=190) groups, respectively. The 95% confidence interval (CI; -0.139, 0.304) of the difference (0.08) was within the pre-specified equivalence margin (-0.6, 0.6). Up to Week 52, the decreases in DAS28-ESR were maintained in all three arms. No notable differences in ACR20/50/70 were observed. The AE and ADA incidences were comparable between the arms.
Conclusions: LBAL was equivalent in efficacy and comparable in safety, including immunogenicity, to ADL. Switching from ADL to LBAL did not impact on efficacy and safety.