ALBERT

Description: Background: Acute renal failure (ARF) is a frequent complication of multiple myeloma (MM) and most frequently due to clonotypic light chains (LC) causing cast nephropathy, which is associated with fast deterioration of renal function, increased risk for infections and shortened survival. Here we present the final results of a phase II study employing lenalidomide-dexamethasone as treatment for patients with acute light-chain induced ARF. Patients and methods: 35 patients with LC-induced ARF have been enrolled. Cast nephropathy was confirmed in all 15 patients who had a renal biopsy. Patients with previously unknown MM must have presented with eGFR 〈 50ml/min and serum creatinine ³2.0mg/dL, and those with previously established diagnosis must have had documented eGFR ³ 60ml/min and serum creatinine ≤1.2mg/dL within 6 weeks before deterioration of eGFR to 〈 50ml/min and of serum creatinine to ≥ 2mg/dL due to LC-induced kidney injury. Nine cycles of Lenalidomide, day 1-21, q28 days, with dose adaptation according to eGFR (eGFR 30 – 50ml/min: 10 mg daily, eGFR 〈 30ml/min without requiring dialysis: 15mg q 48 hrs., eGFR 〈 30ml/min requiring dialysis: 5 mg daily following each dialysis) and dexamethasone (Dex), 40 mg, day 1-4, 9-12 and 17-21 during the first cycle and thereafter 40 mg once weekly were planned. Renal response was defined as previously described (Dimopoulos et al, Clin Lymphoma Myeloma. 2009, Ludwig et al. JCO 2010). Results: Patient's median age was: 66 (45-87), 28 patients had newly diagnosed and 7 previously established MM. 5.7% had ISS stage II, 94.3% stage III. 18 patients had light chain myeloma, 14 IgG, and 3 IgA isotype. Adverse cytogenetics t (4; 14) ± del17q ± 1q21 were detected in 14/29 patients. 4/35 patients died and 5 discontinued therapy (3 due to AEs, 1 due to PD, and 1 due to withdrawal of consent) within the first 2 cycles, leaving 26 patients for per protocol (PP) analysis. Median follow up was 17.7 months. Responses were seen in 25/35 (71.4%) patients; 7 (20%) had CR, 3 (8.6%) VGPR, 14 (40%) PR, and 1 (2.9%) MR. Median time to first and to best myeloma response was 28, and 92 days, respectively. Median baseline concentration of involved FLC was 5.465mg/L (range: 147–42.700mg/L) and 8350mg/L (range: 234– 35.500mg/L) in patients reaching ≥PR and ≤MR, respectively, and decreased significantly to a median of 95.75mg/L (range: 11.3–5.630mg/L, p