The Effects of Induction Chemotherapy and High-Dose Melphalan with Tandem Autologous Transplantation in Multiple Myeloma: The Prospective Randomized DSMM 2 Study.

The concept of the DSMM 2 study was to give age-adjusted high-dose treatment to elderly myeloma patients in order to balance efficacy and toxicity. The value of conventional induction chemotherapy before high-dose melphalan and autologous stem cell transplantation and the durability of unmaintaned remissions afterwards was addressed. Between September 2001 and September 2006, 434 multiple myeloma patients 60–70 years of age with 0–1 cycle of pretreatment were recruited from 45 centers. The median age was 65 years. The patients were randomized to receive 4 cycles of conventional induction chemotherapy [A1] (n=216; VAD or idarubicin/Dex in 88%) or no induction chemotherapy [A2] (n=218). Instead of induction chemotherapy, patients in [A2] received only one short course of dexamethasone 40 mg orally (days 1–4 and 8–11). Subsequently, stem cells were mobilized after combination chemotherapy with ifosfamide, epirubicin and etoposide (IEV) followed by G-CSF; stem cells could be collected in 97% of the patients. Then the patients proceeded to tandem MEL140 (melphalan 140 mg/m2) and autologous peripheral blood stem cell transplantation with a time interval between high-dose cycles of 2 months. No consolidation or maintenance treatment was scheduled. Analyses were performed in an intent-to-treat approach. 87% of patients completed the first transplant, 74% the second. Overall, the treatment was well tolerated and grade 3/4 infections and stomatitis after high-dose melphalan occurred in 37% and 9% of patients, respectively. The overall mortality (tumor and/or toxicity) during treatment was 7.1%: 4.5% during the induction phase (6.1% in [A1] versus 2.9% in [A2]), 1.5% after mobilization and 1.1% after high-dose therapy. Notably, the best response (EBMT criteria) at the end of treatment in patients randomized to [A1] (16% CR, 64% PR) or [A2] (18% CR, 69% PR) was not different. An early loss of tumor control with disease progression occurred in 6% in [A1] versus 1% in [A2]. With a median follow-up time of 20 months, there was no significant difference in the median event-free survival (EFS) (22 months in [A1] versus 20 months in [A2]) and not in the overall survival (OS) at 4 years (63% in [A1] versus 65% in [A2]). In ≥ 50% of patients, the time between last treatment and progression was > 16 months. The EFS of patients 60–64 years of age and 65–70 years of age was the same. In conclusion, there was no benefit of conventional induction chemotherapy with VAD- or VAD-like regimens in patients receiving tandem MEL140 with autologous transplantation. This induction treatment therefore may be avoided. Tandem-MEL140 is feasible and well tolerated in the majority of elderly patients with symptomatic myeloma. Its profound and durable anti-tumor effect was demonstrated by prolonged unmaintained remissions. The addition of new agents given as consolidation or maintenance probably will further improve treatment results.