P-176: Effect of induction regimen in survival in newly diagnosed multiple myeloma patients receiving consolidation with autologous stem cell transplantation

Abstract

<h3>Background</h3> Novel therapies improved the survival of newly diagnosed multiple myeloma patients (NDMM) during the last decades. Nevertheless, autologous stem cell transplantation (ASCT) remains a standard consolidation strategy. How induction therapy affects the outcomes in NDMM patients receiving consolidation with ASCT has not been explored in our region <h3>Objective</h3> To analyze the impact of different induction therapies in NDMM patients receiving consolidation with ASCT in overall survival (OS) and progression-free survival (PFS) <h3>Method</h3> This is a retrospective survival analysis study based on the Grupo de Estudio Latinoamericano de Mieloma Múltiple (GELAMM) registry. We included adults patients with NDMM who received ASCT as frontline consolidation therapy from 6 countries. The induction regimens compared were VCD (Bortezomib, cyclophosphamide, dexamethasone), VTD (Bortezomib, thalidomide, dexamethasone), CTD (Cyclophosphamide, thalidomide, dexamethasone), or VRD (Bortezomib, lenalidomide, dexamethasone). OS and PFS were defined as the time from MM diagnosis until the death/last control or disease progression, respectively. We used SPSSv.25 for statistical analysis. Survival was analyzed using the Kaplan-Meier model with Log-rank test. <h3>Results</h3> Five hundred eighty-five patients were included, with a median age at diagnosis of 55 years (IQR 10), 54% males, 58.6% IgG, 17.8% IgA, 17.8% Light Chain, and 5.8% other subtype. Risk stratification at diagnosis (n=534) showed 30.7% ISS-I, 34.3% ISS-II, and 35% ISS-III. Two-thirds (66.8%) received maintenance therapy. Induction regimen were 55% VCD, 25% VTD, 16.1% CTD, and 3.9% VRD. The proportion of patients by ISS group was similar among all the regimens (p=0.97). Also, the median age was equivalent among the groups included (p=0.23). At end of induction, the rate of very good partial response or better was 51.3% VCD, 56.7% VTD, 48.9% CTD, and 85% VRD. The 5-year OS for the whole group was 82.7%, and the 5-year OS per induction regimen were 82.9% VCD, 83.6% VTD, 80.1% CTD, and 89.5% VRD (Log-Rank, p=0.70). The median OS was not reached in any of the induction regimens. The 5-year PFS (n=368) for the whole group was 27%, and the 5-year PFS per induction regimen were 27.4% VCD, 20.3% VTD, 30% CTD, and 74% VRD (Log-Rank, p=0.23). The median PFS was 42 months for both VCD and VTD, 48 months for CTD, and not reached for VRD. Maintenance therapy was associated with a 5-year OS of 86.60% vs. 80.60% (p>0.05) for patients not receiving maintenance. The 5-years PFS was 30.3% for maintenance vs. 21.2% (p>0.05) in non maintenance. <h3>Conclusions</h3> in this real-world cohort, VRD as induction therapy was associated with deeper response rates and longer PFS and OS. Regardless of the frontline therapy, ASCT achieves a long PFS and OS in NDMM. There is a trend for longer PFS and OS in patients receiving maintenance. Larger number of patients may be needed to allow more robust conclusions.