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

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.

Extended Stability of Reconstituted Lyophilized Erwinia L-asparaginase in Vials.

BACKGROUND/AIM: L-Asparaginase (L-ASNase) is used as a tumor-inhibitory drug on paediatric acute lymphoblastic leukemia (ALL). ERW-ASNase is commercialised as a lyophilized powder stable only for 8 hours once reconstituted and, consequently, the leftover is usually discarded. The aim of this study will be to analyse the stability of the reconstituted lyophilised ERW-ASNase. MATERIALS AND METHODS: In the present study, we analysed the enzymatic stability of reconstituted ERW-ASNase after conservation in three different temperature conditions for 2 and 5 days. RESULTS: Our results show that ERW-ASNase is stable at 4°C, -20°C and -80°C for up to 5 days, retaining 95% of the initial enzymatic activity in all three storage temperatures tested. CONCLUSION: It is feasible to reuse the remaining content of ERW-ASNase vial after reconstitution, which allows the optimization of the content of ERW-ASNase vials use and reduces the cost of this formulation usage, making it more accessible.