Therapeutic drug monitoring‐based dose optimization for imatinib‐associated serious cutaneous reactions in a patient with gastrointestinal stromal tumours: A case report. (1st June 2020) - Huang, Wanting
Abstract: What is known and objective: Imatinib mesylate (IM) is the first‐line therapy for unresectable or metastatic gastrointestinal stromal tumours (GISTs). Here, we report a case of successful progressive dose optimization by therapeutic drug monitoring (TDM) for a patient with GISTs who developed IM‐associated serious cutaneous reactions. Case description: A 72‐year‐old female patient received IM at a dose of 400 mg/day for GISTs. The patient developed serious eczematoid drug eruptions and desquamation, following which IM was discontinued. One year later, the GISTs recurred with metastasis, and IM was re‐administered at a dose of 100 mg/day, and the dose was gradually increased on the basis of TDM. The final dose of IM was 200 mg/day, and the trough concentration ( C trough ) of IM was 1457.76 ng/mL. The images obtained from follow‐up computed tomography (CT) showed a marked anti‐tumour response. IM was well tolerated and the patient developed tolerable IM‐associated cutaneous reactions. What is new and conclusion: The strategy of TDM‐guided dose optimization makes it possible to achieve optimal clinical efficacy for patients with GISTs who develop IM‐associated serious cutaneous reactions. Abstract : We report a case of a 72‐year old female with recurrent GISTs, who required long‐term IM therapy, but the treatment was complicated by dose‐limiting skin toxicity. We successfully performed dose optimization for this patient for generating personalised precision medicines on the basis of TDM and analysis of genetic mutations.