Autologous Stem Cell Transplant Followed by Two Years of Post-transplant Therapy for Older Patients With Multiple Myeloma: A Prospective Phase II Trial

Abstract High dose melphalan and hematopoietic stem cell transplantation (HSCT) is a standard treatment for eligible patients with multiple myeloma (MM). Intensified transplant regimens, if safe, may improve patient outcomes. Thus, we evaluated the safety and efficacy of intensified conditioning with HSCT followed by a two-year triple agent maintenance in patients aged ≥65 with recently diagnosed multiple myeloma MM. The induction therapy was dexamethasone, cisplatin, doxorubicin, cyclophosphamide, and etoposide infusion. This was followed by conditioning with bortezomib, thalidomide, dexamethasone and high dose melphalan with HSCT. Post-transplant maintenance was given for 24 months, consisting of cycles of bortezomib, thalidomide, and dexamethasone followed by cycles of bortezomib, cyclophosphamide, and dexamethasone. We enrolled 41 patients. Median age was 68 years. The best overall response was stringent complete response (sCR) in 85% of patients. The median progression-free survival (PFS) was 76.4 months. The 48-month PFS and overall survival rates were 64% and 83%, respectively. One patient died from transplant related toxicity (2.4%). The high rate of CR, favorable median PFS, and good safety profile demonstrate the feasibility and efficacy of this regimen in older transplant-eligible patients. The study highlights that HSCT should be entertained and is probably the treatment of choice in eligible patients.