Aim: Alectinib (Alecensa®) is an anaplastic lymphoma kinase inhibitor for the treatment of anaplastic lymphoma kinase positive non-small-cell lung cancer, and M4 is its major pharmacologically active metabolite. To characterize the pharmacokinetics and excretion of alectinib and M4 in human urine, a bioanalytical method was required.
Results: An LC-MS/MS method using supported liquid extraction was developed for the determination of alectinib and M4 in human urine over the concentration range 0.5-500 ng/ml. Accuracy ranged from 92.0 to 112.2% and precision (CV) was below 9.6%.
Conclusion: The method was successfully employed to determine alectinib and M4 concentrations in urine samples from a clinical mass balance study. Addition of the surfactant Tween-20 to urine prevented nonspecific binding of the analytes.
Keywords: alectinib; nonspecific binding; urine.