Advances in therapy of multiple myeloma: Lessons from acute leukemia

This paper traces the lack of progress, until recently, in the treatment of multiple myeloma (MM) to having ignored the principles that led to cure in acute leukemia more than 2 decades ago. Only in the mid-1980s did investigation begin to consider complete remission (CR) a research objective, representing a necessary first step toward cure. The experience with autologous and allogeneic stem cell-supported high-dose therapy is reviewed, demonstrating, in both historically controlled and randomized studies, the validity of the dose-response concept in MM in terms of increased CR rates as well as extended event-free (EFS) and overall survival (OS). Avoidance of hematopoietic stem cell-damaging agents, especially melphalan, nitrosoureas, and ionizing radiation to marrow-containing sites, assures the ability of peripheral stem cell collection of high quality and quantity, providing rapid engraftment so that mortality is well under 5% following high-dose melphalan (200 mg/m²). This treatment can be applied safely to patients even >70 years of age and in the presence of renal failure. Tandem autotransplants after multiregimen induction have yielded CR rates in the 40% range with median durations of EFS and OS of 43 and 62 months, respectively. Certain chromosomal abnormalities (11 and 13; and translocations) represent the dominant adverse prognosticator for EFS and OS, confirmed in over 500 patients including those with prior therapy. Allogeneic transplants, possible in less than 10% of MM patients, are associated with a 50% mortality during the first year and, unfortunately, late relapses; thus, this approach should be reserved for patients with high-risk disease early in their management. A risk-based treatment algorithm that matches a patient's disease risk with the risk of intervention is presently used, followed by bisphosphonate therapy, not only to delay the onset of MM-related bone disease but also to induce tumor cell apoptosis, indirectly or directly, by down-regulation of cytokines with antiapoptotic activities. Although many patients relapse, this author subscribes to his mentor's motto: 'Be Prepared for Success!'.