Purpose: Renal impairment (RI) is a common comorbidity in multiple myeloma (MM). Current dose adjustments recommended for renally excreted lenalidomide are based on data from noncancer patients. This study evaluated the pharmacokinetics, safety, efficacy, and exposure-response for lenalidomide plus dexamethasone in patients with relapsed/refractory MM and stable RI using the recommended dose adjustments.
Methods: This phase 2 multicenter, open-label study stratified patients into 5 groups based on creatinine clearance (CrCl) calculated by Cockcroft-Gault equation: normal renal function (CrCl > 80 mL/min), mild RI (50 ≤ CrCl ≤ 80 mL/min), moderate RI (30 ≤ CrCl < 50 mL/min), severe RI (CrCl < 30 mL/min), and end-stage renal disease requiring hemodialysis. Dosing was based on the lenalidomide label.
Results: Among 38 patients, the median age was 68 (range 62-74) years, and poorer renal function was associated with older age, more advanced disease, and more lines of prior therapy. Lenalidomide clearance declined with decreased CrCl. Mean lenalidomide area under plasma concentration-time curve (AUC) was within ±25 % of the target AUC in each group. Overall response was 76 %, and safety profiles were similar across groups, with no exposure-dependent trend in efficacy or toxicity. Estimated glomerular filtration rates calculated using the simplified Modification of Diet in Renal Disease equation highly correlated with lenalidomide clearance and, in 87 % of patients, would lead to assigning the same starting dose of lenalidomide as CrCl.
Conclusions: In patients with stable renal function, the recommended dose adjustments achieved proper plasma exposure and similar safety and efficacy across renal groups.
Keywords: Estimated glomerular filtration rate; Lenalidomide; Pharmacokinetics; Relapsed/refractory multiple myeloma; Renal impairment.