Comparison of branded and generics imatinib plasma concentrations in patients with chronic myelogenous leukemia – unicentric study

• Published in: Clinical lymphoma, myeloma and leukemia
• Main Authors: Ostojic, Alen, Sertic, Dubravka, Roncevic, Pavle, Peric, Zinaida, Granic, Paula, Matic, Nikolina, Basic-Kinda, Sandra, Serventi-Seiwerth, Ranka, Radman, Ivo, Zadro, Renata, Nemet, Damir
• Format: Journal Article
• Language: English
• Published: 2016
• Subjects: Hematology, Oncology and Palliative Medicine; generics; chronic myelogenous leukemia; imatinib mesylate; therapeutic drug monitoring
• ISSN: 2152-2650
• DOI: 10.1016/j.clml.2016.04.003

Abstract Introduction For over a decade, imatinib has been the first-line treatment of Philadelphia chromosome-positive chronic myeloid leukemia (CML). Doubts on the bioequivalence and bioavailability of emerging generic compounds have been expressed. Adequate imatinib plasma concentration (IPC ≥1000 μmol/L) is associated with a better chance of optimal treatment response in CML. In this study we compared the achieved IPCs between the branded compound and its two generic forms. Patients and methods IPCs were compared in 24 consecutive CML patients in first chronic phase who changed from branded to generic imatinib. The median age was 49 (22–76) years. Fifteen of them were male. Six patients were switched to Neopax, 13 to Imakrebin, and 5 patients received both generics consecutively. All compounds were used in an equivalent dose of 400 mg per os once daily for at least one month before plasma concentrations were measured. High-performance liquid chromatography was used to determine imatinib plasma concentration from a specimen collected 21–24 hours after the last dose. Results Median IPC achieved with branded imatinib was 1454 μmol/L (range 485-2707) with 18 patients (75%) having IPC ≥ 1000 μmol/L. For Neopax and Imakrebin, median IPCs were 1717 (1249-3630) and 1458 (707-880) respectively with 11/11 (100%) and 16/18 (89%) patients having IPC ≥ 1000 μmol/L. No significant difference in measured IPCs between all three compounds was found (p>0.257). Conclusion When taken at equivalent doses, imatinib generics are bioequivalent and comparable in clinical efficacy and have the potential for substantial savings in CML treatment cost.