P-372 Transcriptomic expression of BMP-2, BMP-6 and Smad6 genes in newly diagnosed and relapsed multiple myeloma patients

S244the first one with significantly shorter PFS and OS (PFS HR 2.15, CI 1.79-2.58p< 0001, OS HR 2.37, CI 1.86-3.02p< 0.0001).The worse prognostic impact was observed even in the absence of both amp1q and del17p, observed in 38/249 (15%) pts (PFS HR 2.57, CI 1.79-3.70p< 00001, OS HR 2.49, CI 1.57-3.94p=0.0001), compared to 494pts.The risk of relapse defined by the presence of ≥1 ER-CNAs was independent from those conferred both by R-IIS 3 (HR=1.51CI 0.17-2.39-2.2;p=0.01) and by low quality (< stable disease) first-line best clinical response (HR=2.59CI0.33-2.84p=0.004).Notably, the type of induction therapy was not descriptive in this multivariate model, suggesting that ER is strongly related to pts' baseline genomic architecture, and not to induction therapy they were provided to.Conclusions: ML approach allowed to define CNAs-specific dynamic clonality cut-offs, improving the CNAs calls' accuracy to identify MM pts with the highest probability to ER.The use of these ER-related cut-offs pinpointed few CNAs, whose presence at baseline is highly predictive of ER, including amp2p, del2p, del12p, and del19p, whose biological role in MM needs further investigations.As being outcome-dependent, the coMMsol method is dynamic and might be adjusted according to the selected outcome variable of interest (e.g.MRD-negativity) thus providing outcome-specific clonality cut-offs.