Successful treatment of patients with newly diagnosed/untreated light chain multiple myeloma with a combination of bendamustine, prednisone and bortezomib (BPV).

Introduction: Patients with light chain myeloma frequently have a light chain tubular cast nephropathy, which can lead to severe renal impairment. In the present retrospective study, bortezomib was combined with other active substances like bendamustine and prednisone (BPV), in order to assess the efficacy and toxicity of the combination therapy in patients with light chain multiple myeloma.

Methods: Between September 2008 and May 2015, 25 patients with newly diagnosed light chain multiple myeloma were treated with bendamustine 60 mg/m on days 1 and 2, bortezomib 1.3 mg/m on days 1, 4, 8 and 11, and prednisone 100 mg on days 1, 2, 4, 8 and 11 once every 21 days (BPV). Prior to treatment, 4 patients (16%) had moderate renal dysfunction and 14 patients (56%) severe renal dysfunction or renal failure/dialysis.

Results: The median number of the BPV cycles was 2 (1-5). 24 patients (96%) responded with 4 stringent complete responses, 6 near-complete responses, 5 very good partial responses and 9 partial responses. The myeloma light chains decreased rapidly, reaching the best response after the first cycle in 9 and after the second cycle in additional 12 patients. 17 patients discontinued therapy after median 2 cycles of BPV treatment to receive autologous or allogeneic SCT. All together 12 of 18 patients with at least moderate renal failure improved their renal function. 3 of the 6 dialysis-dependent patients became dialysis-independent. With a median follow-up of 27 months, median progression-free survival and overall survival for patients at 30 months were 68 and 96%, respectively. The most common severe side effect was grade 3/4 leukocytopenia in 20% of the patients. Grade 3/4 thrombocytopenia was observed in 12% of the patients. Moderate to severe infection were seen in six patients. We conclude that BPV is effective and well tolerated in patients with newly diagnosed/untreated light chain multiple myeloma.