Predicting long-term disease control in transplant-ineligible patients with multiple myeloma: impact of an MGUS-like signature

Disease control at 5 years would be a desirable endpoint for elderly multiple myeloma (MM) patients, but biomarkers predicting this are not defined. Therefore, to gain further insights in this endpoint, a population of 498 newly diagnosed transplant-ineligible patients enrolled in two Spanish trials (GEM2005MAS65 and GEM2010MAS65), has been analyzed. Among the 435 patients included in this post-hoc study, 18.6% remained alive and progression free after 5 years of treatment initiation. In these patients, overall survival (OS) rate at 10 years was 60.8% as compared with 11.8% for those progressing within the first 5 years. Hemoglobin (Hb) >= 12 g/dl (OR 2.74, p = 0.001) and MGUS-like profile (OR 4.18, p = 0.005) were the two baseline variables associated with long-term disease-free survival. Upon including depth of response (and MRD), Hb >= 12 g/dl (OR 2.27) and MGUS-like signature (OR 7.48) retained their predictive value along with MRD negativity (OR 5.18). This study shows that despite the use of novel agents, the probability of disease control at 5 years is still restricted to a small fraction (18.6%) of elderly MM patients. Since this endpoint is associated with higher rates of OS, this study provides important information about diagnostic and post-treatment biomarkers helpful in predicting the likelihood of disease control at 5 years.
This study was supported by the Centro de Investigacion Biomedica en Red-Area de Oncologia-del Instituto de Salud Carlos III (CIBERONC; CB16/12/00369 and CB16/12/00377), Instituto de Salud Carlos III/Subdireccion General de Investigacion Sanitaria (FIS no. PS09/01897/01370, PI12/01761, PI12/02311, PI13/01469, PI14/01867, G03/136, CD13/00340), Asociacion Espanola Contra el Cancer (GCB120981SAN) and the European Research Council (ERC) 2015 Starting Grant (MYELOMANEXT).