Feasibility and outcome of tandem stem cell autotransplants in multiple myeloma

Clinical trials have shown that high dose chemotherapy (HDT) with peripheral stem cell autotransplantation is presently the best treatment for patients with symptomatic multiple myeloma (MM). In the context of an outcomes research project, we analyzed the feasibility of this strategy in clinical practice in a large cohort of consecutive, unselected patients with newly diagnosed MM and looked at the major determinants of response of patients enrolled in a HDT with tandem autotransplantation (Total Therapy I, TTI) program.

Two hundred and fourteen patients were treated outside of a clinical trial and regularly followed-up at our Center for symptomatic MM. Ninety-seven patients (45%) received conventional chemo-radiotherapy regimens, 110 (51%) entered the TTI program and the remaining 7 patients (3.3%) were enrolled in other programs involving HDT with autotransplantation.

Patients enrolled in HDT with tandem autotransplantation programs were 14 years younger and less likely to have co-morbidities than patients treated with conventional therapy. Median overall survivals of the two groups were 60 and 33 months, respectively. Thirteen percent of the patients enrolled in the TTI program did not receive the first HDT with autotransplantation, mostly because of disease progression, and another 16% did not proceed to the second HDT with autotransplantation mainly because of infections or drug-related complications. Most patients achieved complete remission after the second autotransplantation, with acceptable toxicity. However, only patients with a major reduction of the myeloma burden at the end of induction therapy enjoyed significantly prolonged event-free and overall survivals.

Approximately one third of patients with newly diagnosed symptomatic MM completed the TTI program. These data suggest the need to improve the induction therapy in order to increase both the number of patients able to proceed to autotransplantation programs and to enhance the rate of early response.