Comparable efficacy and safety of generic and branded imatinib for patients with chronic myeloid leukemia in China

Abstract

Background: Generics imatinib became an alternative treatment option for chronic myeloid leukemia (CML) patients in China. However, clinicians and patients alike harbor concerns regarding the long-term safety of generic imatinib. Objectives: Patients with chronic phase CML receiving frontline imatinib treatment. Design: A retrospective study was used to evaluate the blood concentration, effectiveness, and safety of generic in 170 CML patients. Methods: Imatinib plasma concentrations were detected by high-performance liquid chromatography-tandem mass spectrometry. Results: Among the 170 patients, 73 (42.9%) patients treated with branded imatinib as first-line therapy, while 22 (12.9%) switched to generic imatinib during treatment due to economic considerations. No significant differences in trough concentrations between branded and generic imatinib (1549.9 ± 648.8 ng/mL vs 1479.0 ± 507.0 ng/mL; p = 0.95). During the 2-year follow-up, there were no significant differences in molecular response rates (major molecular response (MMR): 33.3% vs 37.0%; deep molecular response: 56.9% vs 42.9%, p = 0.17) between the branded and generic imatinib. Both groups showed similar rates of switching to second-generation tyrosine kinase inhibitor (11.8% vs 15.1%, p = 0.56). Furthermore, there were no significant differences in event-free survival or failure-free survival between branded and generic imatinib. Twenty-two (12.9%) switched to generic imatinib during treatment, 68.2% maintained their level of response, 27.3% improved, and only one patient (4.5%) lost MMR. There were no significant differences in the incidence of various adverse events. Conclusion: Generic imatinib are equally effective and safe compared to branded molecules, both for newly diagnosed patients and those who switch from branded.