CHICAGO – Up-front high-dose melphalan and autologous stem cell transplantation (ASCT) was superior to bortezomib-melphalan-prednisone (VMP) for fit patients younger than age 65 years with newly diagnosed multiple myeloma, based on the interim results from a randomized study of the European Myeloma Network.
With more than 1,200 patients, the study is the largest trial yet to show superior progression-free survival for ASCT. Follow-up has been too short to show significance for overall survival.
“Up-front ASCT was associated with a significant improvement in progression-free survival as compared to bortezomib-melphalan-prednisone in the overall patient population, (and the advantage) was retained across prespecified subgroups of patients at low and high risk … (as well as) in a multivariate analysis” of the overall population, Dr. Michele Cavo of the University of Bologna, Italy, reported at the annual meeting of the American Society of Clinical Oncology. “Up-front high-dose melphalan and ASCT continue to be the reference treatment choice for fit patients with newly diagnosed multiple myeloma, even in the novel agent era.”
ASCT was associated with higher rates of grade 3 or more adverse events in nearly every category, however, with the exception of peripheral nephropathy.
For the study, 1,266 patients, stratified by International Staging System stage and FISH (fluorescence in situ hybridization) analysis, were randomized to either VMP (512 pts) or to high-dose melphalan and ASCT (754 pts). At the meeting, Dr. Cavo reported on the study’s interim outcome results in 695 patients who had ASCT and 497 newly diagnosed patients who received VMP.
At 3 years, progression-free survival rates were 66.1% in the ASCT patients and 57.5% in the VMP patients. The median progression-free survival had not yet been reached in the ASCT patients and was 44 months in the bortezomib-melphalan-prednisone patients. (hazard ratio, 95% confidence interval, 0.73 [0.59-0.90]; P = .003).
Stringent complete responses were seen in 18.2% of patients in the VMP group and 17% of the ASCT group; Complete responses occurred in 25.3% of both groups. The main difference observed was in the number of very good partial responses, seen in 30.4% of the VMP group and in 43.2% of the ASCT group. Also, 11.2% of those in the VMP group had less than a partial response while that was the case for only 3.3% of the ASCT group.
Alternatively, the rate of grade 3 or more adverse events was higher in the ASCT group, with 17.5% experiencing febrile neutropenia, 15.6% mucositis, 3.2% sepsis, and 2.6% respiratory infections. The rates of these side effects in the VMP group were 0.2%, 0%, 0%, and 1.7%, respectively. The only grade 3 or more adverse event seen with greater frequency in the VMP group was peripheral neuropathy, seen in 13.8% as compared with 1.6% in the ASCT group.
Dr. Cavo receives honoraria from Amgen, Bristol-Myers Squibb, Celgene, Janssen, and Takeda. He serves as a consultant or advisor to and is on the speakers bureau for Amgen. Celgene, Janssen.
On Twitter @maryjodales
This story was updated on June 10, 2016.