PB1950 GENERIC IMATINIB FOR THE TREATMENT OF CHRONIC MYELOID LEUKAEMIA‐ CLINICAL EXPERIENCE OVER A SIX YEAR PERIOD

Background: Upon the introduction of the first tyrosine kinase inhibitor (TKI), imatinib, the treatment of chronic myeloid leukaemia has radically changed. The very high treatment cost is unfortunately a major issue that pushes over the boundaries of healthcare budgets, even in developed countries. For this reason, healthcare policies encourage the use of generic drugs to reduce costs, leading to concerns regarding their efficacy, safety and quality. Aims: From September 2013 Cypriot pharmaceutical services approved the use of imatinib generic drugs that have been approved from the European Medical Agency. The aim of this study is to compare the effectiveness of generic versus brand‐name imatinib. Methods: We studied 44 patients over a six year period, from February 2013 until February 2019. 25 patients were diagnosed before September 2013 and commenced treatment with the brand‐name imatinib. The remaining 19 patients were diagnosed after September 2013 and commenced treatment with generic imatinib. The two groups were similar in regards to age, gender and characteristics of the disease (Sokal, Hasford, EUTOS). We recorded any change in response, side effects and differences in individual responses at 3, 6 and 12 months of treatment after switching from the brand‐name imatinib to generic. The evaluation of patients was in accordance to the guidelines of European Leukaemia Net. Results: Among the 25 patients in the group that received original imatinib at the start of their treatment, eight switched to another tyrosine kinase inhibitor due to adverse reactions or unsatisfactory response. From the remaining 17, 13 continued on the dose of 400 mg and had achieved major molecular remission which was retained even after the change to generic imatinib. The other four patients achieved major molecular remission on higher doses (according to the European protocol at the time) that was also retained after the change to generic imatinib. Among the 19 patients that were diagnosed after September 2013 and received generic imatinib at the beginning of their treatment, two switched to another tyrosine kinase inhibitor due to adverse reactions or unsatisfactory response. Another two did not achieve the optimal molecular remission according the ELN guidelines and are being closely monitored and evaluated. The other 14 patients remain in major molecular remission after an 18 month evaluation. The median study time was 38 months (3‐65 months) The percentage of non‐responsiveness does not differ statistically in the two patient groups. Regarding the side effects, there was no difference between the generic imatinib compared to the original imatinib. Summary/Conclusion: It appears that the imatinib generics have the same effectiveness as the original without additional side effects. It should be mentioned that during the six years of this study, the patients received whichever generic imatinib drug was available at the time. The above results do not take into consideration the potential differences between the generic brands of imatinib.