Analysis of imatinib for therapeutic drug monitoring in patients with
adjuvant and neoadjuvant therapy for gastrointestinal stromal tumours
using UPLC-MS/MS
Abstract
In China, 1100 ng/mL is used as the recommended threshold for imatinib
Cssmin in therapeutic drug monitoring (TDM) for metastatic
recurrence/unresectable gastrointestinal stromal tumors (GIST) patients.
However, there are few studies on characteristics of imatinib Cssmin for
adjuvant therapy after complete resection of GIST and neoadjuvant
therapy. Consider individual differences of GIST patients, analysis of
imatinib in patients with adjuvant and neoadjuvant treatment using a
quantitative ultra-performance liquid chromatography coupled with tandem
massspectrometry (UPLC-MS/MS) method was conducted in this study. This
developed method showed good selectivity and reliability. 25 blood
samples collected from October 2019 to October 2021 in 16 patients with
adjuvant therapy and 9 patients with neoadjuvant therapy were
determined. In the neoadjuvant treatment group, all patients initially
received 400 mg/d imatinib. The range of the imatinib steady-state
plasma concentration (Cssmin) was 1083-4722 ng/mL. In the adjuvant
treatment group, the imatinib Cssmin was in the range of 584-2692 ng/mL
after patients given at a dosage of 200, 300, 400 and 600 mg/d. There is
no statistical difference in Cssmin between two groups after receiving
400 mg/d imatinib (p=0.402). Among all patients given 400 mg/d imatinib,
the Cssmin was significantly correlated with gender (P=0.016).