For patients with multiple myeloma (MM), more treatment does not necessarily mean better outcomes, according to results from the phase III StaMINA trial, which enrolled 758 transplant-eligible patients with symptomatic MM (median age = 57 years; range = 20-70 years) in one of three treatment arms:
- Standard of care: melphalan 200 mg/m2 plus autologous hematopoietic cell transplantation (AHCT; n=257)
- Consolidation: standard care plus 4 cycles of consolidation (lenalidomide 15 mg on days 1-14; dexamethasone 40 mg on days 1, 8, and 15; and bortezomib 1.3 mg/m2 on days 1, 4, 8, and 11 every 21 days; n=254)
- Tandem: standard of care plus a second AHCT (n=247)
All patients had received at least two cycles of any regimen as initial systemic therapy and were within two to 12 months of the first dose of initial therapy at the time of enrollment. Patients were excluded if they had received prior HCT, were previously treated with melphalan >50 mg intravenously, had disease progression prior to enrollment, or received lenalidomide as initial therapy for MM and have experienced toxicities resulting in treatment discontinuation.
All arms included maintenance therapy with lenalidomide 5 mg to 15 mg daily until progression.
At a median follow-up of 38 months, progression-free survival (PFS; defined as disease progression, initiation of non-protocol anti-myeloma therapy, or death) was not significantly improved in patients in the consolidation or tandem arms compared with the standard of care, at 52 percent in the standard-of-care arm, 57 percent in the consolidation arm, and 56 percent in the tandem-transplant arm (p=0.37). Rates of overall survival (OS) at 30 months were also similar among the three groups: 82.0 percent, 85.7 percent, and 83.4 percent, respectively. Median OS had not been reached at the time of presentation.
Thirty-nine patients (5.1%) developed secondary malignancies, and these rates were similar across the three treatment arms (15 in the consolidation arm, 14 in the tandem-transplant arm, and 10 in the standard-of-care arm). There was no difference in treatment-related mortality.
The investigators, led by Edward A. Stadtmauer, MD, section chief of hematologic malignancies at the Abramson Cancer Center at the University of Pennsylvania in Philadelphia, noted that the findings are limited by poor protocol adherence in the double AHCT arm (32% of patients did not receive the planned second AHCT). Future clinical trials are needed to examine the reasons for not proceeding to assigned treatment, as well as the correlation between MM biologic factors and outcomes.
The researchers concluded that AHCT plus lenalidomide maintenance therapy should remain the standard of care in MM. “When compared with the current standard course of treatment alone, these data suggest that additions to standard MM therapy do not improve benefit for patients,” Dr. Stadtmauer said during his presentation of the study results, adding that there is always room for improvement. “New therapies and interventions need to be actively investigated to see how much they further benefit the early treatment of patients with myeloma. I believe it would be reasonable to compare any new treatments to the standard therapy of melphalan followed by a single AHCT followed by lenalidomide maintenance.”
Stadtmauer EA, Pasquini MC, Blackwell B, et al. Comparison of autologous hematopoietic cell transplant (autoHCT), bortezomib, lenalidomide (len) and dexamethasone (RVD) consolidation with len maintenance (ACM), tandem autohct with len Maintenance (TAM) and autohct with len maintenance (AM) for up-front treatment of patients with multiple myeloma (MM): primary results from the randomized phase III trial of the Blood and Marrow Transplant Clinical Trials Network (BMT CTN 0702 – StaMINA Trial). Abstract LBA-1. Presented at the 2016 ASH Annual Meeting, December 6, 2016; San Diego, California.