Abstract

7534 Background: Patients (pts) with high-risk (HR) Multiple Myeloma (MM), characterized by at least two cytogenetic abnormalities often experience rapid disease progression and early relapse post-autologous stem cell transplant (ASCT) with median Progression-Free Survival (PFS) of 24 or 12 months with or without lenalidomide maintenance (Panopoulou et al, Blood 2023). This study assesses the efficacy and safety of EPD (Elotuzumab, Pomalidomide, Dexamethasone) or ERD (Elotuzumab, lenalidomide , Dexamethasone) as consolidation therapy post-ASCT in HR MM pts. Methods: In this single-center retrospective study, we reviewed records of MM pts treated with consolidative ERD or EPD from September 2016 to March 2023. We collected baseline MM characteristics, treatment history, adverse events (AEs), and survival outcomes. HR MM pts were defined by 2 or more cytogenetic abnormalities (del 17p, 1q21 gain or amplification, t(14;16), t(14;20), complex karyotype) and/or high-risk gene expression profiling scores (GEP, SKY92). All patients, aged ≥21, underwent ≥1 full cycle of EPD or ERD post-ASCT, administered for a total of four 28-day cycles, following the standard dosing regimen with a rapid dexamethasone taper over the last two cycles. Results: A total of 78 HR MM pts, median age 64 years with 51.2% males and 71.7% caucasians were included. Of them, 62 pts received ERD and 16 received EPD. FISH revealed 62.7% of pts had 2 or more high risk cytogenetic abnormalities. Other pts expressed a combination of cytogenetic abnormalities and/or high-risk GEP or SKY92 scores. The table shows improvement in MRD negativity rates from 21.7% to 26.9% pre and post consolidation, and in VGPR or better from 78.2% to 85.8%. Median PFS for all pts, defined from the time of ASCT to disease progression, was 26.9 months. Most common adverse effects were anemia (71.7%), fatigue (55.1%) and thrombocytopenia (51.2%). Five patients experienced grade 3 adverse events, including 3 with infectious etiology (3.8%) and 2 with immune-mediated toxicity (2.5%). No treatment-related serious adverse events were reported. Conclusions: Four cycles of EPD or ERD consolidation therapy post-ASCT, demonstrated promising efficacy in HR MM pts. The observed median PFS of 26.9 months was comparable to that seen with chronic lenalidomide maintenance and superior to patients who do not receive lenalidomide maintenance. The improvement in PFS was achieved with a fixed duration rather than continuous therapy and without lenalidomide-associated toxicities such as secondary malignancies, chronic diarrhea, and financial toxicity. Further prospective confirmatory studies are needed. [Table: see text]