Cyclophosphamide, Bortezomib and Dexamethasone (CYBORD) Treatment for Relapsed/Refractory Multiple Myeloma

report a series of 55 patients with relapsed/refractory MM and their response to CYBORD. Methods: 55 patients with relapsed/refractory MM were treated with CYBORD on a 28 day cycle. Dosing was cyclophosphamide 300 mg/ m 2 PO once weekly; bortezomib 1 (2%), 1.3 (22%) or 1.5 mg/ m 2 (76%), IV (89%) or SQ (11%), once (87%) or twice weekly (13%); and dexamethasone 40 mg PO once weekly. We report response using the IMWG criteria 3 , and new onset neuropathy based on NCI CTCAE 4 . Results: Mean age was 65.6 years and 56% were male. Of the 55 patients, 64% had progressed while on therapy and 56% had a previous ASCT. Mean number of previous treatment lines was 3.3, and 36% and 82% were proteasome inhibitor (PI) and CYBORD naive. Median follow up time was 24.1 months and mean number of cycles was 5 (±4.4). ORR was 71%, 26% had ≥VGPR, and 13% CR. PI naive patients had an ORR of 95% while patients who had previously received a PI had an ORR of 57%. Median PFS and OS were 9.2 and 29 months, respectively. After a mean of 6 cycles, 22% of patients underwent subsequent ASCT. New onset grade 1 neuropathy was present in 16% of patients, while only 2% had grade 2 and none had grade 3 or greater neuropathy. We found an increase in PFS in PI naive patients (14.8 v 5.2 months, HR 0.4, 95%CI 0.2-0.7), patients that underwent a subsequent ASCT (19.7 v 6.3 months, HR 0.3, 95%CI 0.2-0.7) and patients that had ≤3 prior treatment lines (12 v 6.1 months, HR 0.5, 95%CI 0.2-0.8); no difference was found by mSMART 5 risk or prior ASCT. An increase in OS was found only in PI naive patients (35.4 v 21.2 months, HR 0.5, 95%CI: 0.3-0.98) and patients that underwent a subsequent ASCT (53.1 v 26.7 months, HR 0.3, 95%CI 0.2-0.8); no difference was found by number of previous treatment lines, mSMART risk or prior ASCT. Conclusions: CYBORD is an effective treatment regimen without significant increase in side effect profile for patients with relapsed/ refractory MM, achieving better outcomes in PI naive patients and those who undergo a subsequent ASCT, regardless of mSMART risk.