Imatinib plasma levels in patients with chronic myeloid leukaemia under routine clinical practice conditions

• Published in: Journal of oncology pharmacy practice Vol. 29; no. 1; pp. 40 - 44
• Main Authors: Del Rosario García, Betel, González García, Iris, Viña Romero, María Micaela, González García, Jonathan, Ramos Díaz, Ruth, Mourani Padrón, Ivette, Lakhwani Lakhwani, Sunil, Nazco Casariego, Gloria Julia, Gutiérrez Nicolás, Fernando
• Format: Journal Article
• Language: English
• Published: London, England SAGE Publications 01-01-2023; Sage Publications Ltd
• Subjects: Antineoplastic Agents - therapeutic use; Chronic myeloid leukemia; Clinical medicine; Humans; Imatinib; Imatinib Mesylate - therapeutic use; Inhibitor drugs; Leukemia; Leukemia, Myelogenous, Chronic, BCR-ABL Positive - drug therapy; Patients; Plasma; Plasma levels; Pyrimidines - therapeutic use; Targeted cancer therapy; Toxicity; plasma concentrations; Chronic myeloid leukaemia; imatinib; pharmacokinetic monitoring; plasma levels
• ISSN: 1078-1552; 1477-092X
• DOI: 10.1177/10781552211052535

Introduction
The addition of imatinib to the therapeutic arsenal for chronic myeloid leukaemia (CML) has changed the natural course of the disease, in such a way that it is now considered a chronic pathology. However, to achieve therapeutic success, it is necessary to reach adequate plasma concentrations to ensure efficacy and safety.
In this study, we aimed to evaluate the plasma concentration of imatinib, analysing its influence on effectiveness and safety in patients with CML.
Methods
We performed a descriptive, multicentre study in which imatinib plasma levels from patients diagnosed with CML between 2019–2020 were analysed. An optimal therapeutic range of 750–1500 ng/mL was established for the stratification of patients, according to their minimum plasma concentrations measured at steady state (Cssmin).
Results
A total of 28 patients were included, of whom only 39.3% (n = 11) showed Cssmin within the therapeutic range. 100% of patients with Cssmin >750 ng/mL achieved an optimal molecular response, while only 50% of patients with Cssmin <750 ng/mL achieved an optimal molecular response (p = 0.0004). The toxicity rate was 36.4% for patients with Cssmin >1500 ng/mL and 5.9% for those with Cssmin <1500 ng/mL (p = 0.039).
Conclusions
This study aimed to describe the correlation between the toxicity and effectiveness of imatinib according to its Cssmin in routine clinical practice conditions. Based on our findings, it would be certainly justified to monitor patient plasma concentrations of imatinib on a daily routine basis in our hospitals.