Combined Bendamustine, Prednisone and Bortezomib (BPV) In Patients With Relapsed Or Refractory Multiple Myeloma and Light Chain Induced Renal Failure

Serious renal failure represents a main complication of Multiple Myeloma (MM). An estimated 25% to 50% of patients are affected during the course of their disease. These patients are at increased risk for infections and have a significantly worse prognosis. Small phase I/II studies suggest that treatment with chemotherapy and/or new substances results in recovery of renal function in more than 25%. The window of opportunity for reversal of renal impairment is rather small making an immediate and highly active treatment strategy mandatory. Bortezomib and bendamustine have turned out to be quickly acting and effective drugs in the treatment of MM.

Between March 2005 and March 2013, 36 patients (median age 64; range 32-81 years) with relapsed/refractory MM and light chain induced renal failure (creatinine clearance <60ml/min) were treated with bendamustine 60mg/qm on day 1 and 2, bortezomib 1.3mg/qm on day 1, 4, 8 and 11, and prednisone 100mg on day 1, 2, 4, 8 and 11. Cycles were repeated every 21 days. Patients were divided into two groups: group A (n=20) consisted of patients with moderate or severe renal dysfunction (eGFR 15-59ml/min) and group B (n=16) of patients with renal failure/dialysis (eGFR <15ml/min).

The median number of the BPV-treatment was 2 (1-7) cycles. 24 patients (67%) responded after at least one cycle of chemotherapy with 3 CR, 3 nCR, 6 VGPR, and 12 PR. Six patients had MR, 2 patients stable disease and 4 patients had a progress. With a median follow up of 22 months of the surviving patients, median PFS and OS for patients with moderate or severe renal dysfunction (group A) were 10 months and 25 months, respectively. Outcome for these patients was significantly better compared to patients with renal failure/dialysis (group B) with a median PFS and OS of 3 months and 7 months, respectively (p<0.02).

Eleven patients showed a CRrenal, 5 patients a PRrenal and 15 patients a MRrenal. Median time to first renal response and best renal response were 21 days and 42 days, respectively. The most common severe side effect was grade 3-4 thrombocytopenia in 81% of the patients. Grade 3-4 neutropenia was observed in 50% of the patients. Moderate to severe infections were seen in 13 patients.

These results indicate that the combination of bortezomib, bendamustine and prednisone is effective and well tolerated in patients with relapsed/refractory MM and light chain induced renal failure.

No relevant conflicts of interest to declare.