PurposeLenvatinib is an oral multi-kinase inhibitor prescribed in renal cell carcinoma (RCC), endometrial cancer (EC), hepatocellular carcinoma (HCC), and radioactive iodine-refractory differentiated thyroid cancer (DTC). Lenvatinib is poorly tolerated at the recommended label dose (RLD), with > 60% of patients requiring dose modifications. Given that studies have identified an exposure-response relationship, therapeutic drug monitoring (TDM) has been proposed as a potential strategy to improve tolerability. This single-centre study reviews lenvatinib dosing across cancer types and discuss the potential role of TDM.MethodsMedical records from a hospital in South Australia were retrospectively reviewed for patients treated with lenvatinib between December 1, 2016, and December 31, 2023. Data on cancer diagnoses, dose, and demographics were collected and analysed.ResultsEighteen patients (19 treatment episodes), median age 61 years (range: 34-79), received lenvatinib. Cancer types included DTC (n = 10), EC (n = 4), HCC (n = 3), RCC (n = 1), and adenoid cystic carcinoma (n = 1). Lenvatinib was started at a reduced dose in 42% of the treatment episodes, and of these episodes 87% were never escalated to the RLD. At least one adverse event related to lenvatinib was reported in 95% of all treatment episodes during the study period; adverse events were identified from clinical documentation and were not graded using standardised criteria.ConclusionThis study suggests variability in clinical practice relative to labelled recommendations for lenvatinib dosing. Even with initial dose reductions, adverse events and treatment interruptions still occur. Future studies should define target lenvatinib concentrations to facilitate clinical TDM application.
Tan et al. (Thu,) studied this question.