Sequential treatment with bortezomib plus dexamethasone followed by autologous hematopoietic stem cell transplantation in patients with multiple myeloma.

BACKGROUND

Whether the sequential treatment with bortezomib plus dexamethasone (BD) followed by autologous hematopoietic stem cell transplantation (ASCT) could extend the overall survival period in multiple myeloma patients is still not clear. Few large case studies about this therapeutics in multiple myeloma were reported in China. Our purpose was to assess the efficacy and adverse effects of sequential treatment with BD chemotherapy and ASCT in patients with multiple myeloma.

METHODS

Fifty-three patients with newly diagnosed or relapsed/refractory multiple myeloma received BD as induction therapy before ASCT. Stem-cell mobilization was undertaken with cyclophosphamide 3 - 5 g/m(2) plus granulocyte colony-stimulating factor 300 µg/d. Target yield was 2.0×10(6) CD34(+) cells/kg. Conditioning for ASCT consisted of melphalan 200 mg/m(2). Thalidomide and/or a-interferon was used as post-transplantation maintenance treatment.

RESULTS

The BD chemotherapy before transplantation was effective in 86.7% of the 53 patients, including 22.6% with complete remission (CR), 39.6% with near complete remission (nCR), and 24.5% with partial remission (PR). The best effect was achieved after two treatment courses. Most bortezomib-related adverse effects were classes 1 - 2. All patients were successfully mobilized after BD for autologous peripheral blood stem cell transplantation. The ASCT was effective in 96.3% of patients, including 49.1% with CR, 32.1% with nCR, and 15.1% with PR. The CR rate was significantly increased (49.1% vs. 22.6%, P < 0.05) by sequential ASCT. Within 27 (range, 6 - 53) months of follow-up, the efficacy of ASCT was maintained in 29 patients and further enhanced by post-transplantation maintenance treatment in four patients. Eleven patients died after transplantation. Among the patients undergoing BD/ASCT treatment, overall survival (OS) was significantly better in newly diagnosed patients in comparison to relapsed/refractory patients (P = 0.046).

CONCLUSIONS

BD chemotherapy can be used as an induction therapy prior to ASCT in patients with multiple myeloma. Its rate of effectiveness is high and it alleviates symptoms quickly without affecting peripheral blood stem cell collection. The majority of adverse effects are mild (tolerable). Sequential BD with ASCT is the preferred option for transplant patients. First-line ASCT could prolong survival of newly diagnosed patients rather than delayed ASCT.