MM-161: Real-World Cytogenetic Testing Among Patients with Multiple Myeloma in the United States

Context: High-risk cytogenetic features in patients with multiple myeloma (MM) have been linked to poorer prognosis. Improved outcomes for these patients remain a high unmet medical need. Objective: To assess high-risk cytogenetic testing and to describe the relationship of cytogenetic testing to line(s) of therapy in a real-world patient population. Patients: Using the USA-based Flatiron Health EHR-derived de-identified database, 7660 MM patients diagnosed between January 2011 and November 2019 who initiated first-line therapy were included in this analysis. Patients were high-risk if they had del[17p], and/or t[4;14], and/or t[14;16]; standard-risk if abnormalities were absent for all three markers; and unknown risk if otherwise. Flatiron Health, Inc. did not participate in the analysis of this data. Outcome Measures: Prevalence of cytogenetic testing and timing of testing relative to treatment were assessed. Common therapies for first, second, and third lines by cytogenetic risk, as well as overall survival (OS) from first-line initiation by cytogenetic risk were examined. Results: Prevalence of cytogenetic testing was 72%; 62% had testing prior to first-line therapy. Patients with no evidence of cytogenetic testing were older (mean 70.4 vs 67.5 years), more likely to be Black (18% vs 15%), to have an unknown stage at diagnosis (56% vs 39%), and to be diagnosed in an earlier year in the dataset timeframe. Among patients tested, 17% were high-risk, 34% standard-risk, and 49% were unknown/undocumented. Among high-risk patients, common first line-therapies were bortezomib (V), lenalidomide (R) and dexamethasone (d) (43%), Vd (13%), and cyclophosphamide (C) Vd (12%). Common second-line therapies were VRd (14%), Rd (11%), and carfilzomib (K)Rd (7%). Common third-line therapies were pomalidomide (P)d (8%), Kd (7%), and daratumumab (D)Pd (6%). OS from initiation of first-line therapy was shorter for high-risk vs standard-risk patients (median, 3.8 vs 6.1 years). Conclusions: High-risk testing was common and mostly occurred before first-line therapy, highlighting the importance of cytogenetic status as a prognostic factor in MM patients. Future work may improve understanding of the prognostic value of cytogenetic testing and optimal treatment regimens for high-risk patients.