Imatinib mesylate: Recent drug used in oncology

Background: The European Union and Canada have approved generic imatinib for the treatment of chronic myeloid leukaemia (EU). Anecdotal evidence suggests that generic imatinib performs less well than brand-name imatinib. MEDLINE and EMBASE were searched as methods. The European Medicines Agency (EMA) and Health Canada-approved generic imatinib product monographs were examined. We contacted Novartis, Teva, and Apotex's medical information.

Results: A number of issues have been brought up. First, generic imatinib approved outside of Canada and the EU has been linked to inconsistent results in two case series and lower efficacy in minor case reports. However, it is unclear whether these generic products' clinical bioequivalence has been established. Second, there have been concerns raised about generic imatinib's use in different populations. However, compared to adults with chronic myeloid leukaemia, imatinib absorption is not significantly different in children with chronic myeloid leukaemia or in patients with gastrointestinal tumours. Even though there have been reports of reduced absorption following gastric bypass and gastrectomy, the majority of imatinib is absorbed in the ileum, duodenum, colon, and jejunum. It has also been demonstrated that changes in stomach acidity have no impact on imatinib absorption. At room temperature, the beta-crystal form of brand-name imatinib is more stable than the alpha-crystal form of generic imatinib. However, the EMA discovered that both crystal forms were extremely soluble and that polymorphism would not materially affect the efficacy of generic imatinib.