Cyclophosphamide, Bortezomib and Dexamethasone (CyBORD) Is a Feasible and Active Regimen for Non-Transplant Eligible Multiple Myeloma Patients

Introduction With the advent of novel drugs for the treatment of Multiple Myeloma (MM), the clinical outcomes have significantly improved over the last decade both in the setting of stem cell transplant eligible and non-eligible patients. Combinations of novel drugs have improved and deepened response and this is true for CyBORD, a regimen able to induce rapid and deep responses. Based on the above mentioned, we aimed to assess the role and feasibility of CyBORD as upfront therapy for non-transplant eligible patients with MM.

Methods. All consecutive patients with documented symptomatic MM not eligible for transplant treated with CyBORD at our Institution were evaluated. Treatment consisted of a 28-day cycle of bortezomib 1.3 mg/m² or 1.5 mg/m² intravenously or subcutaneously on days 1, 8, and 15, cyclophosphamide 300 mg/m² orally administered on days 1, 8, and 15 and dexamethasone 20-40 mg orally on weekly basis. Definitions of response and progression were used according to the EBMT modified criteria and a category of very good partial response (VGPR) was added. The primary endpoint of the study was to assess the efficacy and feasibility of CyBORD in this group of patients. All analyses were performed using the SPSS 20.0 software and all p-values were 2-sided and statistically significant if <0.05.

Results Between 07/11 and 07/14, 20 patients were identified for the study. Clinical and laboratory characteristics are listed in Table 1. The median age for this cohort of patients was 76 years (range 66-90). Sixty-five percent of patients had IgG isotype, 5% had IgA, and 30% had light chain only disease. After a median of 5 cycles, the overall response rate was 95% (19/20) with 70% of patients achieving VGPR or better response. (Table 2 ) The median time to first response was 6 weeks with majority of cases achieving at least PR after 2 cycles of therapy. At a median follow-up of 9.5 months, all patients are alive and 5 had already progressed at a median time of 12 months. With regards to toxicity, 6 patients experienced non-hematological grade 3/4 adverse events (20%), including muscle weakness, sepsis and pneumonia. Neutropenia and thrombocytopenia were seen in 2 patients (10%), both patients required dose reduction of cyclophosphamide with one patient being discontinued of cyclophosphamide after 2 cycles but still receiving bortezomib and dexamethasone.

In conclusion, CyBORD is a highly active and viable option for the treatment of non-transplant eligible patients with MM. As suggested by other studies, elderly patients required dose adjustments and special considerations while receiving active therapy, balancing the efficacy and toxicity given by the different drug combinations.

CyBORD: Cyclophosphamide, bortezomib and dexamethasone