Cyclophosphamide-bortezomib-dexamethasone compared with bortezomib-dexamethasone in transplantation-eligible patients...

Cyclophosphamide-bortezomib-dexamethasone (CyBorD) is considered a standard induction regimen for transplant-eligible patients with newly diagnosed multiple myeloma (mm). It has not been prospectively compared with bortezomib-dexamethasone (Bor-Dex). We aimed to compare the efficacy of CyBorD and Bor-Dex induction in transplant-eligible patients.

In a retrospective observational study at a single tertiary centre, all patients with transplant-eligible mm who received induction with CyBorD or Bor-Dex between March 2008 and April 2016 were enrolled. Progression-free survival (pfs), response, and stem-cell collection for a first autologous stem-cell transplantation (ahsct) were compared.

Of 155 patients enrolled, 78 (50.3%) had received CyBorD, and 77 (49.7%), Bor-Dex. The patients in the Bor-Dex cohort were younger than those in the CyBorD cohort (median: 57 years vs. 62 years; p = 0.0002) and more likely to have had treatment held, reduced, or discontinued (26% vs. 14.5%, p = 0.11). The stem-cell mobilization regimen for both cohorts was predominantly cyclophosphamide and granulocyte colony-stimulating factor (gcsf). Plerixafor was used more often for the CyBorD cohort (p = 0.009), and more collection failures occurred in the CyBorD cohort (p = 0.08). In patients receiving Bor-Dex, more cells were collected (9.9×10⁶ cells/kg vs. 7.7×10⁶cells/kg, p = 0.007). At day +100, a very good partial response or better was achieved in 75% of the CyBorD cohort and in 73% of the Bor-Dex cohort (p = 0.77). Median pfs was 3.2 years in the Bor-Dex cohort and 3.7 years in the CyBorD cohort (p = 0.56).

Overall efficacy was similar in our patients receiving CyBorD and Bor-Dex. After ahsct, no difference in depth of response or pfs was observed. Cyclophosphamide-gcsf seems to increase collection failures and hospitalizations in patients receiving CyBorD. Prospective studies are required to examine that relationship.