The Absorption and Release of Lenalidomide
After oral administration of lenalidomide under fasting conditions in healthy subjects, the product can be rapidly absorbed and the plasma concentration reaches the maximum within 0.5 to 1.5 hours. In patients and healthy subjects, the maximum plasma concentration (Cmax) and the area under the plasma concentration time curve (AUC) can increase proportionally with increasing doses. Multiple doses did not result in significant drug accumulation. The relative exposure of lenalidomide S- and R-enantiomers in plasma is approximately 56% and 44%, respectively. When healthy subjects receive high-fat and high-calorie foods at the same time, the degree of absorption decreases, resulting in a 20% decrease in AUC and a 50% decrease in Cmax. However, in the key registration trials establishing the efficacy and safety of lenalidomide in the treatment of multiple myeloma, the feeding state was not taken into consideration when administered. Therefore, lenalidomide can be taken with food and an empty stomach as well.
In vitro, 14C-lenalidomide has a lower binding rate to plasma proteins, with the average plasma protein binding rates of 23% and 29% in multiple myeloma and healthy subjects. After lenalidomide 25 mg/day was administered to healthy subjects, it was detected in the semen (the content was less than 0.01% of the dose). After 3 days of drug withdrawal, the product was not detected in the semen.