Introduction: Bortezomib is a proteasome inhibitor that has shown important clinical efficacy either as a single agent or in combination in patients with multiple myeloma (MM). In the present protocol, bortezomib was combined with bendamustine and prednisone, in order to assess the efficacy and safety of this combination therapy in patients with newly diagnosed/untreated MM.
Methods: Between June 2006 and October 2013, 49 patients with newly diagnosed/untreated MM were treated with bendamustine 60 mg/m(2) on days 1 and 2, bortezomib 1.3 mg/m(2) on days 1, 4, 8 and 11, and prednisone 100 mg on days 1, 2, 4, 8 and 11 bendamustine, prednisone and bortezomib (BPV) once every 21 days. Patients were divided into three groups: group A (n = 19) consisted of patients with normal renal function or mild dysfunction (eGFR ≥ 60 ml/min), group B (n = 15) patients with moderate or severe renal dysfunction (eGFR 15-59 ml/min) and group C (n = 15) patients with renal failure/dialysis (eGFR <15 ml/min).
Results: A median number of two (range 1-5) BPV treatment cycles were given to the patients. The majority of the patients (n = 40, 82 %) responded after at least one cycle of BPV therapy with five stringent complete responses (CRs), nine near complete responses, 12 very good partial responses and 14 partial responses. Five patients had MR, three stable and one progressive disease. After a median observation time of 13 months, progression-free survival (PFS) and overall survival (OS) at 12 months were 92 and 94 %, respectively, for patients with normal renal function or mild renal dysfunction (group A) and 83 and 93 %, respectively, for patients with moderate or severe renal dysfunction (group B). Outcome for these patients was slightly better but not statistically significantly better than that for patients with renal failure/dialysis (group C), who had a PFS, and OS of 66 % (p = 0.08) and 73 % (p = 0.05), respectively. These results indicate that this BPV combination is feasible, effective and well tolerated in patients with newly diagnosed MM and normal or impaired renal function.