Jason Mendler, MD
If you didn’t feel like traveling to some of our nation’s larger auto shows this year, there was a pretty good one that took place over the last two days at this year’s annual meeting. Covering a wide variety of diseases and novel transplant approaches, the oral and poster presentations on the clinical results of autologous stem cell transplantation (ASCT) had something for everyone. There was a suggestion of the prognostic power of PET scans in myeloma treated with ASCT, the possibility of curing follicular lymphoma with ASCT, and optimism regarding new conditioning regimens in relapsed non-Hodgkin lymphoma and refractory Hodgkin lymphoma. In multiple sclerosis, ASCT with reduced-intensity conditioning was demonstrated to be an effective approach for halting, and in many cases improving, neurological symptoms. One of the most important themes coming out of these sessions was the focus on strategies to improve outcomes after ASCT in multiple myeloma (MM).
During Sunday’s oral presentation, Dr. Philip McCarthy discussed interim results of CALGB 100104, a phase III intergroup study of lenalidomide versus placebo maintenance therapy following single ASCT for MM (abstract #37). With a median follow-up of 17.5 months from ASCT, the number of events (progression or death before progression) among 231 patients randomized to lenalidomide was 44 compared to 91 among 229 patients randomized to placebo. This translates into a 61 percent reduction in the risk of an event in patients on lenalidomide versus placebo. Importantly, this therapy was reasonably well tolerated with only a small minority of patients discontinuing therapy due to an adverse event.
Continuing on this theme, A. Keith Stewart reported on the NCIC CTG MY.10 Trial, a randomized phase III trial of thalidomide and prednisone (thal/pred) as maintenance therapy following ASCT in patients with MM (abstract #39). Similar to the results of CALGB 100104, thal/pred resulted in a prolonged progression-free survival, although there was no benefit in overall survival. This regimen had substantial toxicity and resulted in a reduced quality of life in study participants.
A theoretical approach to reducing relapse rates after ASCT for MM involves allogeneic transplantation. Dr. Amrita Krishnan reported results from the Blood and Marrow Transplant Clinical Trials Network (BMT CTN) 0102 Trial, a study that compared tandem ASCT (auto-auto) to single ASCT followed by HLA-matched sibling non-myeloablative allogeneic HCT (auto-allo) for patients with standard risk (SR) MM (abstract #41). In total, 625 patients with SR MM were assigned to either auto-auto (436) or auto-allo (189), based on availability of an HLA-matched sibling donor. At a follow-up of three years, there was no statistically significant difference in progression-free (46 percent auto-auto vs. 43 percent auto-allo) or overall survival (80 percent auto-auto vs. 77 percent auto-allo) between groups. As would be expected, treatment-related mortality and morbidity were higher in the auto-allo arm. Based on these and other results, there is still no clear role for allogeneic transplantation in MM.
Dr. Mendler indicated no relevant conflicts of interest.