Lenalidomide (Len)-Melphalan-Prednisone Induction Followed By Len Maintenance (Mpr-R) In Newly Diagnosed Multiple Myeloma (Ndmm) Elderly Patients (Pts) With Moderate Renal Impairment (Ri): Mm-015 Trial Post-Hoc Analysis

8544 Background: The MM-015 pivotal phase III trial showed significant PFS benefit for MPR-R (31 mos) vs. MPR (14 mos) or MP (13 mos; both p < 0.001) followed by placebo in NDMM pts aged ≥ 65 years. As NDMM pts with RI have poor prognosis, this retrospective analysis studied the efficacy and safety of MPR-R in pts with creatinine clearance (CrCl) < 60 mL/min. Methods: LEN starting dose for induction/maintenance was 10 mg/day (D1–21 of a 28-day cycle). Dose adjustments were not recommended for pts with RI. CrCl was calculated using the Cockcroft-Gault equation. Pts with severe RI (serum Cr > 2.5 mg/dL [221 μmol/L]) were excluded from the trial. Results: Pts with CrCl < 60 mL/min (median 47, interquartile range [IQR] 38–55) were included in this analysis: 51% MPR-R, 45% MPR, and 49% MP. Median PFS was significantly higher with MPR-R (26 mos [95% CI 14–48]) vs. MPR (13 mos [95% CI 12–15]) or MP (14 mos [95% CI 12–16]; both p < 0.001). In a Cox proportional model of PFS, CrCl < 60 mL/min was not identified as a negative prognostic factor (p = 0.69). The most common Gr 4 adverse events (AEs) were hematologic and occurred predominantly during induction and are shown in the Table for pts with or without moderate RI. The number of deaths on study was similar: 10% (MPR-R), 7% (MPR), and 8% (MP); deaths associated with RI or disease progression were reported in ≤ 1% of pts with RI across the arms. Conclusions: The benefit of continuous LEN treatment with MPR-R is not compromised in NDMM pts with moderate RI, consistent with the overall trial results. CrCl and AEs should be monitored closely in this population. Clinical trial information: NCT00405756. [Table: see text]