Autotransplant with and without induction chemotherapy in older multiple myeloma patients: long-term outcome of a randomized trial

Autologous transplantation is controversial for older patients with multiple myeloma. The role of age-adjusted high-dose melphalan and the impact of preceeding induction chemotherapy cycles has been unclear. A total of 434 patients 60 to 70 years of age were randomly assigned to 4 cycles of standard anthracycline-based induction chemotherapy or no induction cycles. For all patients, double autologous transplantation after melphalan 140 mg/m2 (MEL140) was planned. The primary end point was progression-free survival. Of 420 eligible patients, 85% received a first transplant and 69% completed double transplantation. Treatment duration was short with a median of 7.7 months with induction chemotherapy cycles and 4.6 months without it. On the intention-to-treat basis, median progression-free survival with induction chemotherapy cycles (207 patients) was 21.4 months versus 20.0 months with no induction cycles (213 patients) (hazard ratio 1.04, 95% confidence interval [CI] 0.84 to 1.28; P=0.36). Per protocol the progression-free survival was 23.7 months versus 23.0 months (p=0.28). For patients with age ≥ 65 years (55%) the outcome was not inferior. Patients with low-risk cytogenetics (absence of del17p13, t(4;14) and 1q21 gains) showed a favorable overall survival and included the patients with sustained first remission. MEL140 was associated with a low rate of severe mucositis (10%) and treatment-related deaths (1%). Based on the hazard ratio, the short treatment trunk consisting of mobilization chemotherapy and tandem MEL140 with autologous transplantation achieved 96% of the progression-free survival, demonstrating value as an independent component of myeloma therapy in older patients with multiple myeloma regarded fit for autologous transplantation (NCT 02288741).