Effectiveness and safety of adalimumab biosimilar ABP 501 in Crohn's disease: an observational study.

Background and objective: there are no studies in the literature about the effectiveness of adalimumab biosimilar ABP 501 in Crohn's disease.The aim of this study was to evaluate its effectiveness and safety. Methods: an observational study was performed in Crohn's disease patients treated with ABP 501, with the classic induction and maintenance regimen and in Crohn's disease patients who were switched from the adalimumab originator to ABP 501. Results: eighty-seven patients were included in the study, of which 25 were naive to the adalimumab originator and 62 were switched to ABP 501. In adalimumab-naive patients, clinical response at three months was 60 % (15/25) and clinical remission at three months was 56 % (14/25). At six months, 95.2 % (59/62) of the patients switched to ABP 501 were still in therapy, without a significant increase of clinical activity (Harvey-Bradshaw index from 3.4, 95 % CI = 2.4-4.4, to 3.8, 95 % CI = 2.7-4.9, p = 0.23) and inflammatory biomarkers (C-reactive protein from 4.2 mg/l, 95 % CI = 2.5-5.9 mg/l, to 3.6 mg/l, 95 % CI = 2.2-5 mg/l, p = 0.32).There were no unexpected adverse events during the study period. Conclusions: our results support ABP 501 as an effective and well-tolerated drug, with a good interchangeability with its originator for the treatment of Crohn's disease.