Comparative Safety of Targeted Therapies for Metastatic Colorectal Cancer between Elderly and Younger Patients: a Study Using the International Pharmacovigilance Database.

Abstract

Metastatic colorectal cancer (mCRC) is increasingly treated using targeted therapies. Post-marketing safety of these agents is understudied, especially in the elderly. This study aimed to compare, according to age, the adverse drug reactions (ADRs) of targeted therapies used for mCRC in real life. An extraction of VigiBase, which contains World Health Organization individual case safety reports (ICSRs), was performed. All ADR reports with aflibercept, bevacizumab, cetuximab, panitumumab, or regorafenib used in CRC were considered. For all drugs, chi-square tests were used to compare frequencies of serious ADRs between patients aged ≥75 and <75years. For selected ADRs and each drug, the drug-ADR association compared to other anticancer drugs was estimated through the proportional reporting ratio (PRR) in both age groups. There were 21,565 ICSRs included, among which 74% were serious and 11% were fatal. Median age was 64years (Inter Quartile Range=56-71) and 15% of patients were aged ≥75; 57% were male. Serious ICSRs accounted for 47,292 ADRs. Neutropenia was not more reported in elderly for all drugs while diarrhea was more reported in elderly for panitumumab. Cardiac disorders were more reported in elderly patients, in particular heart failure, especially for bevacizumab, cetuximab, and regorafenib, as were respiratory, thoracic, and mediastinal disorders. Most of PRR were not different between the two groups, except encephalopathies, which were significantly associated with bevacizumab in the elderly only. ADRs related to targeted therapies used for mCRC treatment were different across age groups; yet, not systematically more reported or worse in elderly patients. Selected elderly patients could, therefore, be treated with these targeted therapies.