Treatment Of Relapsed/Refractory Multiple Myelonta With Weekly Cyclophosphamide Plus Hortezoitiib Plus Preduisuite Or Dexamethasone (Cylior-P/D): Updated Experience At Princess Margaret Cancer Centre (Pmcc).

e19568 Background: We previously defined the efficacy of CyBor-P, a 28-day regimen consisting of cyclophosphamide 300 mg/m2 (days 1,8,15, 22), bortezomib 1.5 mg/m2 (days 1,8, 15) and prednisone 100 mg q 2 days in a phase I/II trial involving patients (pts) with relapsed/refractory multiple myeloma (rel/refr MM) [Reece et al, JCO 2008; 26; 4777]. Variations of this regimen have since been reported (bortezomib weekly and replacement of prednisone with dexamethasone), along with its use as first-line therapy. Methods: We now retrospectively review our PMCC experience with CyBor-P/D in rel/refr pts who received ≥ 1 cycle of this regimen to gauge its effectiveness in the real-world setting. Results: Between 2007 and 2013, 98 pts with rel/refr MM received CyBor-P (prednisone 50-100 mg q 2 days) or CyBor-D (dexamethasone 20-40 mg/wk). Median age was 64 yrs (36-86); median # prior regimens was 2 (1-6), including ASCT (75%), bortezomib (28%) and IMiDs (85%). Median creatinine was 94 umol/L (range 53-900). Pts rece...