Implementing a treatment registry for a biosimilar: continuous safety surveillance of the biosimilar Bevax[R]

Introduction and study objectives: Benefit-risk evaluations are essential throughout the life cycle of a drug to guarantee therapeutic efficacy for the authorized indications without an unacceptable incidence of adverse effects. To achieve this, a registry, assessment of adverse drug reactions (ADRs) and other pharmacovigilance (PhV) procedures are mandatory. Due to the inherent variability of bio-production, this is particularly important for biological medicines, including biosimilars. Bevax[R], a biosimilar of the reference product bevacizumab (Avastin[R]), first launched in Argentina in November 2016 after authorization was granted in June 2016. Since launch, an active PhV programme has registered and assessed the incidence of ADRs related to the post-marketing use of Bevax[R]. The aim of this descriptive study was to analyse and summarize the data contained in the treatment registry (TR) surveillance database established to monitor the post-marketing use of Bevax[R]. Methods: Data (including indications and associated ADRs) related to patients treated with Bevax[R] recorded in the Argentinian TR database from November 2016 to 28 May 2018 was analysed. Results: 818 registry forms were collected during the study interval, from which follow-up was available for 416. The product was used for approved indications in most patients (N = 805, 98.4%). A total of 44 individual case safety reports (ICSRs) were received involving 51 ADRs (26 serious). The most frequently reported ADR was related to underlying disease progression (15 events), followed by off-label use (11 events) and hypertension (5 events). Other ADRs with more than one report were neutropenia, sepsis and epistaxis (two events each), whilst the remaining ADRs were reported as single events. Discussion: Data from the Argentinian TR supports the clinical use of Bevax[R] for the authorized indications, with any associated ADRs generally being consistent with those of the reference product. There was no evidence of specific patterns and reports were generally in accordance with the known safety profile of bevacizumab. Nevertheless, the relatively low number of ICSRs precludes the establishment of a reliable safety profile for the product in this context. Conclusion:This may be the first published report summarizing the post-marketing pattern of use and ADRs associated with a biosimilar in Latin America. It emphasizes the need to further develop and implement additional effective PhV activities to inc