Outcome with Lenalidomide Plus Dexamethasone Followed by Early Autologous Stem Cell Transplantation In the ECOG E4A03 Randomized Clinical Trial

Lenalidomide and bortezomib have moved into the management of newly diagnosed multiple myeloma leading to dramatically improved outcomes. As a consequence, the role of upfront autologous peripheral blood stem cell transplant (ASCT) has become more controversial. The ECOG E4A03 clinical trial randomized newly diagnosed MM patients to lenalidomide with high-dose dexamethasone (LD) vs lenalidomide with low-dose dexamethasone (Ld) (Rajkumar et al Lancet Oncol 2010; 11: 29–37). Upon completing four cycles of therapy, pts had the option of ASCT or continuing on the assigned therapy. The purpose of this abstract is to determine the outcome of patients on this trial pursuing early ASCT according to various age-groups.

This is a post hoc, retrospective analysis of overall survival within age subgroups stratified by early ASCT status. This is a landmark analysis including only pts surviving the first 4 cycles of therapy.

In all three age-groups studied, 1, 2, and 3-year survival probability estimates with ASCT were excellent (Tables 1, 2, and 3). For patients under the age of 65 who survived the first 4 cycles of therapy, overall survival at 3-years was 94% with early ASCT, 78% in pts continuing protocol therapy. Although direct comparison with patients not going to early transplant is not possible because the assignment to early ASCT versus no early ASCT was not randomized, survival with ASCT at 3-years appeared higher. While we attempt to correct for age, the differences may be influenced by other factors such as performance status, comorbidities, response to therapy, etc. The presumption that treatment related mortality (TRM) should be more problematic for older pts undergoing ASCT is addressed by looking at the >65 and >70yo cohorts. In the >65 age group, one-year mortality is similar between the early ASCT population and the no early ASCT population. In the >70 age group, no adverse impact of early ASCT was seen in the first year on overall survival but the sample size is extremely small. In all age groups early ASCT seemed to mitigate some of the survival disadvantage associated with randomization to the LD arm.

This analysis shows that the strategy of lenalidomide plus dexamethasone induction followed by early ASCT has a remarkably good outcome in terms of overall survival in all age groups studied and supports the continued role of early consolidative ASCT in newly diagnosed patients. The risk of early mortality was notably low in the first year in all age groups. The risk of early mortality seems to increase at 2 years for the LD pts not choosing early ASCT and at 3 years for the Ld pts not choosing early ASCT. Selection bias makes it difficult to compare results for pts that chose early ASCT directly to the patients who did not receive early ASCT in this trial. As such, these results emphasize the need for randomized trials investigating the timing of ASCT in myeloma in the era of novel therapy.

Siegel:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Millennium Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Merck: Membership on an entity's Board of Directors or advisory committees. Off Label Use: Lenalidomide for front line therapy. Abonour:Celgene: Speakers Bureau; Millennium Pharmaceuticals: Speakers Bureau. Callander:Millennium Pharmaceuticals: Research Funding. Fonseca:Amgen: Consultancy; Bristol-Myers Squibb: Consultancy; Celgene: Consultancy, Research Funding; Genzyme: Consultancy; Onyx: Research Funding; Otsuka: Consultancy; Medtronic: Consultancy. Vesole:Celgene: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau.