Safety Profile of Biological Medicines as Compared with Non-Biologicals: An Analysis of the Italian Spontaneous Reporting System Database

Background Biologicals are important treatment options for various chronic diseases. After the introduction of the first biosimilars, animated debate arose in the scientific community about the actual benefit–risk profile of these drugs. In this context, a comparative safety evaluation of biologicals and biosimilars in clinical practice is warranted. Methods We identified all suspected adverse drug reactions (ADRs) concerning biological/biosimilars (excluding vaccines, toxins, blood derivatives, and radio-pharmaceuticals), and further classified them into mechanistic classes. We described the frequency of biological/biosimilar class- and compound-specific ADRs by system organ class (SOC) and type of reporter. We also separately explored the traceability of biologicals and biosimilar-related ADR reports. Results Overall 171,201 ADR reports were collected during the observation period; 9,601 (5.6 %) of these concerned biologicals. Biological-related reports were mainly issued by hospital-based physicians (78.7 %). Most of these reports involved monoclonal antibodies and fusion proteins (66.3 %). Reported ADRs were mainly ‘skin and subcutaneous tissue disorders’ (21 %), ‘general and administration site disorders’ (17 %), and ‘gastrointestinal disorders’ (13.6 %). In terms of traceability, 94.8 % of biological-related reports included an identifiable product name, whilst only 8.6 % indicated the corresponding batch number. Regarding biosimilars, 298 reports were identified, with a low proportion indicating drug ineffectiveness (10.1 %). Conclusions Most ADRs attributed to biologicals are ‘skin and subcutaneous tissue disorders’. Anticancer monoclonal antibodies are most frequently associated with ADRs. A low proportion of ADR reports concern biosimilars.