Bendamustine-bortezomib-dexamethasone is an active and well-tolerated regimen in patients with relapsed or refractory multiple myeloma

Abstract

Bendamustine with bortezomib and dexamethasone was evaluated in 79 patients with relapsed/refractory multiple myeloma. Median age was 64 years, and patients had a median of 2 prior treatment lines (range, 1 to 6 lines). Bendamustine 70 mg/m(2) days 1 and 4; bortezomib 1.3 mg/m(2) intravenously days 1, 4, 8, and 11; and dexamethasone 20 mg days 1, 4, 8, and 11 once every 28 days was given for up to 8 cycles. Primary end point was overall response rate (ORR). Secondary end points were progression-free survival (PFS), overall survival, time to response, and toxicity. ORR was 60.8%, and when minor responses were included, 75.9%. Median time to response was 31 days. ORR rate was similar in patients previously exposed to bortezomib, lenalidomide, and bortezomib plus lenalidomide. PFS was 9.7 and OS was 25.6 months. Multivariate analysis showed high lactate dehydrogenase, ≥3 prior treatment lines, and low platelet counts correlating with short survival. Grade 3/4 thrombocytopenia was noted in 38%, and grade 3/4/5 infections were noted in 23%. Grade ≤2 polyneuropathy increased from 19% at baseline to 52% at cycle 8 and grade 4, from 0% to 7%. Bendamustine-bortezomib-dexamethasone is active and well tolerated in patients with relapsed/refractory myeloma. This trial was registered in the EudraCT database as No. 2008-006421-13.

Figures

Figure 1

PFS and OS in different patient cohorts. PFS and OS in (A) all patients and (B) patients with standard-risk and high-risk cytogenetics. (C) PFS and (D) OS in patients with International Staging System (ISS) stage I-II and stage III disease. (E) PFS and (F) OS in patients with fewer than 3 or more than 3 prior treatment lines. n.r., not reached; pre-TXT, pretreatment.

Figure 2

PFS and OS related to pretreatment. (A) PFS and (B) OS in patients with and without lenalidomide (Len) pretreatment. (C) PFS and (D) OS in patients with and without bortezomib (Boz) pretreatment. (E) PFS and (F) OS in patients with or without pretreatment with both lenalidomide and bortezomib.