Pharmacokinetic and bioequivalence of lenalidomide in multiple myeloma patients

Purposes: The physiological and pathological conditions of individuals could influence the absorption and metabo-lism of drugs in vivo, so this study assessed the bioequivalence and pharmacokinetics of lenalidomide 25 mg capsules (test formula-tion) and Revlimid 25 mg capsules (reference formulation) in Chinese patients with mul-tiple myeloma (MM). Materials and meth-ods: A multicenter, open-label, randomized, two-period, crossover trial was established to evaluate a single capsule of test and ref-erence formulations under fasting condi-tions. Pharmacokinetic parameters were assessed, and adverse events (AEs) were monitored throughout. Results: Overall, 40 patients with MM completed the study. 17 AEs were reported, among which there was 1 serious event during the study. Geometric ratios for the maximum plasma concentra-tion (Cmax) (98.50%; 90% confidence interval (CI), 91.89 - 105.60%), area under the plas-ma concentration-time curve (AUC) from time 0 to the last measurable concentra-tion (AUC(0-t)) (94.74%; CI, 92.07 - 97.50%), and AUC from time 0 to infinity (AUC(0-infinity)) (95.55%; CI, 93.07 - 98.09%) all met bio-equivalence criteria. Statistics of the data of 39 patients after oral administration of lenalidomide (both test and reference for-mulation) demonstrated that plasma expo-sure tends to increase with age. Conclusion: The two formulations of lenalidomide 25 mg displayed similar pharmacokinetic profiles and were bioequivalent. Age was verified to change the pharmacokinetics of lenalido-mide, as increasing age was correlated with higher total exposure.