Retrospective Comparison of Transplant Outcomes in Patients with Multiple Myeloma According to Induction Therapy with Thalidomide/Dexamethasone (TD) with or without Bortezomib (VTD).

Background: Thalidomide/Dexamethasone (TD) has become one of the most commonly used induction therapies for patients with symptomatic multiple myeloma (MM) eligible for high dose therapy (HDT) intensification with autologous stem cell transplant (ASCT). Bortezomib (Velcade) has been added to the combination of TD (VTD) in an effort to reduce MM tumor burden further prior to HDT.The impact of this addition on HDT outcomes has not been fully explored.

Purpose: To determine the impact of the addition of bortezomib to TD induction therapy in patients with MM undergoing HDT and ASCT consolidation.

Patients and Methods: Patients were eligible for this analysis if they had undergone HDT with ASCT for first remission consolidation or primary refractory disease within 12 months of diagnosis between 9/03 and 12/05 and had received either TD or VTD as induction therapy. Patients receiving VTD after TD were excluded. Patients receiving more than 1 chemo regimen other than TD or VTD were excluded. Chemomobilization was NOT considered an exclusion criteria. Results A total of 78 patients qualified for the analysis (27 VTD; 51 TD). Patient and treatment characteristics are summarized in table 1. In brief, the patients receiving VTD had a higher rate of cytogenetic abnormalities and received less cycles of chemotherapy prior to SCT. Although pre-SCT response rates were similar between patients receiving VTD or TD (95% vs 92%) there was a trend for a higher CR rate in the VTD group (15% vs 6%). Post transplants response rates assessed between 3–6 months demonstrated that 28% and 38% of VTD patients achieved near CR and CR respectively while 19% and 23% had these responses post TD induction. There was no difference in 2 year OS and PFS among patients receiving VTD or TD (91% vs 81% and 35% and 56% respectively).

Conclusion: Both VTD and TD as induction treatment are associated with high response rates prior to SCT as well as 6 months post SCT. In this retrospective analysis no survival benefit was seen for induction therapy with VTD over TD, despite higher near CR and CR rates. However randomized trials need to be performed addressing type of induction as well as duration of induction therapy prior to high dose therapy consolidation.