Pharmacokinetic and bioequivalence of lenalidomide in multiple myeloma patients.

Purposes: The physiological and pathological conditions of individuals could influence the absorption and metabolism of drugs in vivo, so this study assessed the bioequivalence and pharmacokinetics of lenalidomide 25 mg capsules (test formulation) and Revlimid 25 mg capsules (reference formulation) in Chinese patients with multiple myeloma (MM).

Materials and methods: A multicenter, open-label, randomized, two-period, crossover trial was established to evaluate a single capsule of test and reference formulations under fasting conditions. 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 concentration (C_max) (98.50%; 90% confidence interval (CI), 91.89 - 105.60%), area under the plasma concentration-time curve (AUC) from time 0 to the last measurable concentration (AUC_(0-t)) (94.74%; CI, 92.07 - 97.50%), and AUC from time 0 to infinity (AUC_(0-∞)) (95.55%; CI, 93.07 - 98.09%) all met bioequivalence criteria. Statistics of the data of 39 patients after oral administration of lenalidomide (both test and reference formulation) demonstrated that plasma exposure 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 lenalidomide, as increasing age was correlated with higher total exposure.