Prognostic impact of rapid reduction of involved free light chains in multiple myeloma patients under first-line treatment with Bendamustine, Prednisone, and Bortezomib (BPV).

INTRODUCTION: Light chain involvement is observed in almost every patient (pt) with newly diagnosed multiple myeloma (MM). Owing to a relatively short half-life, rapid reduction in the involved free light chain (iFLC) is of potential prognostic value. METHODS: This retrospective analysis included 92 pts with newly diagnosed MM treated with bendamustine, prednisone, and bortezomib (BPV). RESULTS: After a median number of two (range 1-5) BPV cycles, the majority of pts (n = 86; 93%) responded with either sCR (n = 21), CR (n = 1), nCR (n = 25), VGPR (n = 20), or PR (n = 19). PFS and OS at 48 months were 39% and 67%, respectively. At baseline, 79 out of 92 pts (86%) had iFLC levels above the upper standard level and an abnormal ratio of involved to uninvolved free light chain ≥ 8. In a subgroup analysis of these pts, we evaluated the prognostic importance of an early reduction of the iFLC during the first two BPV cycles. A reduction ≥ 50% of the iFLC on day 8 of the first cycle was observed in 31 of 69 pts. These pts had a significantly better median PFS of 49 months as compared to 20 months in 38 pts with a lower iFLC reduction (p = 0.002). In contrast, OS did not differ significantly with a 48 months survival of 77% vs 69% (p > 0.05). CONCLUSION: These results indicate that a rapid decrease in the iFLC on day 8 is an early prognostic marker for newly diagnosed MM pts undergoing BPV treatment.

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/m2 on days 1 and 2, bortezomib 1.3 mg/m2 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.