Real-world intensive safety monitoring of biosimilars rituximab and trastuzumab in a Portuguese oncology hospital.

PURPOSE: The aim of this study was to assess the safety profiles of two biosimilar medicines (rituximab and trastuzumab) in the treatment of cancer patients within a Portuguese oncology hospital. METHODS: This hospital-based prospective observational study followed a cohort event monitoring approach focused on signalling suspected adverse drug reactions (ADRs). Patients undergoing treatment with rituximab biosimilar CT-P10 (Truxima®) or trastuzumab biosimilar CT-P6 (Herzuma®) were recruited over an 11-month and a 6-month period, respectively. Clinicians identified eligible patients and used paper-based forms to report all ADRs associated with biosimilar medicines. ADR case reports were assessed for seriousness, expectedness and causality in the Pharmacovigilance Unit of Coimbra. RESULTS: Ninety-four patients received biosimilar medicines (rituximab, n = 35; trastuzumab, n = 59). Of those, 4 patients (11.4%) experienced 16 ADRs with rituximab and 1 patient (1.7%) experienced 5 ADRs with trastuzumab. All case reports contained serious and expected ADRs that were at least probably related with biosimilar medicines under study. Based on the MedDRA PT coding, the most reported ADR for rituximab CT-P10 was chest discomfort (n = 4; 19.1%), followed by odynophagia (n = 2; 9.5%). Trastuzumab CT-P6 was associated with back pain, headache, pain in extremity, tachypnoea and tremor (each, n = 1; 4.8%). CONCLUSION: The results of this study suggest that using biosimilar rituximab and biosimilar trastuzumab to treat cancer patients in the real-world clinical setting is associated with acceptable safety profiles. No new safety problems were identified.

Intensive safety monitoring program of antineoplastic medicines: A pilot study in a Portuguese oncology hospital.

PURPOSE: The aim of this study was to test the feasibility and the usefulness of an intensive safety monitoring program to identify adverse drug reactions for medicines under additional monitoring that are used to treat cancer patients within a Portuguese oncology hospital. METHODS: This pilot intensive safety monitoring program was a three-month prospective, observational study. Patients undergoing treatment with one of the following medicines were included: nivolumab, olaparib, palbociclib, pembrolizumab, pertuzumab, ramucirumab, ribociclib, trastuzumab emtansine, or trifluridine/tipiracil. Potential eligible patients were identified by pharmacists based on prescription data. Clinicians used proper paper-based reporting forms to record adverse drug reactions. Clinical secretariats sent those reports through an electronic platform to the pharmacovigilance department for analysis. RESULTS: Seventy-five patients were on treatment with selected medicines. Of those, 33 (44%) experienced adverse drug reactions: 23 (69.7%) cases were serious and 5 (15.2%) unexpected. Considering the number of patients exposed to each medicine and the number of patients experiencing adverse drug reactions, trifluridine/tipiracil (72.7%; 8/11) was associated with the highest rate of toxicity, followed by olaparib (66.7%; 2/3), trastuzumab emtansine (50.0%; 3/6), pertuzumab (47.8%; 11/23), pembrolizumab (45.5%; 5/11), palbociclib (25.0%; 1/4), and nivolumab (18.8%; 3/16). A total of 59 adverse drug reactions were identified (i.e. 1.8 adverse drug reactions/patient), mainly gastrointestinal disorders (n = 15; 25.4%), and blood and lymphatic system disorders (n = 14; 23.7%). CONCLUSION: This intensive safety monitoring program was feasible and allowed identifying serious and unexpected adverse drug reactions, adding value to pharmacovigilance and therefore contributing to improve patient safety. Further research is needed to confirm the findings of this pilot study.