Analysis of treatment efficacy in the GEM-CESAR trial for high-risk smoldering multiple myeloma patients: Comparison between the standard and IMWG MRD criteria and QIP-MS including FLC (QIP-FLC-MS)

8512 Background: The GEM-CESAR trial is a potentially curative strategy for high-risk smoldering multiple myeloma (HRsMM) patients (pts) in which the primary endpoint is the achievement of sustained minimal residual disease (MRD) negativity in the bone marrow (BM) by next generation flow (NGF). The value of BM MRD assessment in MM is proven, but alternative, non-invasive methods, accurately reflecting disease burden are needed. Methods: Pts received six 4-week cycles of KRd as induction (K:36mg/m2 twice weekly, R: lenalidomide 25mg po od days 1-21 and d:dexamethasone 40mg po weekly) followed by melphalan 200mg/m2, two further cycles of KRd as consolidation and up to 2 years of Rd (R:10mg/d…