Autologous Stem Cell Transplantation—An Important Step Toward Improving Survival in Multiple Myeloma
Conventional chemotherapy has been used in the treatment of multiple myeloma; however, the development of autologous stem cell transplantation (ASCT) represented a major advance in the therapy. Complete response (CR) rates of 40–45% were seen and this translated into improvements in progression-free survival (PFS) and overall survival (OS) in some studies. As a result, ASCT is the standard of care in eligible patients and can be carried out with low treatment-related mortality. The introduction of newer agents such as thalidomide, lenalidomide, bortezomib, and liposomal doxorubicin into induction regimens has resulted in higher CR rates, very good partial response rates (VGPR), and improvements in the ease of administration. These drugs have also proved useful in patients with adverse cytogenetics. Recent trials suggest that this has translated into improvements in response rates post-ASCT. There is a suggestion that patients achieving CR/near-CR (nCR) or VGPR after induction therapy should be placed on maintenance and ASCT could then be used as a treatment strategy at relapse; however, all of these trends await confirmation from further trials. Tandem transplants have been used to augment the results obtained with ASCT and have demonstrated their utility in patients who achieved only a partial response or stable disease in response to the first transplant and patients with adverse cytogenetics. Incorporation of bortezomib along with melphalan into the conditioning regimen has also been tried. It is hoped that recent advances in therapy will contribute greatly to improved survival.