Re-transplantation after bortezomib-based therapy.
Whilst the use of high dose alkylating agents and autologous stem cell transplantation (ASCT) has a fundamental role in consolidating initial anti-tumour induction therapy, its role in salvage therapy consolidation remains to be determined. Bortezomib has been shown to be an effective agent at first and subsequent relapse, with responses equivalent or better than the response to previously used conventional therapies in first-line therapy (Richardson et al, 2005; Laubach et al, 2009). Combining bortezomib re-induction with a second ASCT after maximal anti-tumour response is, therefore, an attractive concept. Accordingly, we undertook a retrospective review of patients proceeding to a second ASCT after bortezomib-based re-induction therapy. Patients undergoing a second ASCT after progression from an initial ASCT and subsequent bortezomib re-induction therapy in 12 centres were identified (n = 40). Detailed information on the patients was obtained through anonymized clinical data retrieval forms, capturing critical patient and disease-specific factors including response to initial induction therapy, response to first ASCT, time to progression, subsequent therapies, bortezomib-based re-induction therapy and response to second ASCT (including the type of transplant and stem cell source). Response to therapy was categorized according to the International Myeloma Working Group criteria (Durie et al, 2006). Kaplan Meier plots were made using the Statistical Package for the Social Sciences (spss) IBM, Chicago, Illinois, USA. There were insufficient cytogenetic data for analysis. A total of 40 patients were identified in this retrospective study. Two patients had planned reduced intensity allogeneic (RIC-Allo) transplants after their second autologous transplant and weren excluded from further analysis. Patient characteristics including age, sex, type of myeloma, therapy prior to their first and second transplants are shown in Table Ia. One patient who relapsed 10 months after their bortezomib therapy was transplanted in relapse. All other patients were transplanted prior to disease progression. Twenty-six patients were treated with a combination of bortezomib and dexamethasone, eight patients had PAD chemotherapy (bortezomib, adriamycin and dexamethasone (Oakervee et al, 2005). Two patients had bortezomib monotherapy, one patient had bortezomib plus intravenous melphalan and one patient had bortezomib plus cyclophosphamide, dexamethasone and idarubicin. The median number of cycles of bortezomib therapy was 4 (range 2–12). Patients receiving PAD chemotherapy also had a median of four cycles