Treatment Patterns and Outcomes of Multiple Myeloma (MM) with Chromosome Translocation (11;14) in United States (US) Routine Clinical Practice

Introduction: MM is an incurable disease with risk categorizations by cytogenetic abnormalities. Prognostic implications of chromosome translocation t(11;14)+ are important to inform development of biomarker-targeted therapies such as the B-cell lymphoma-2 (BCL-2) pathway inhibitors. This study aims to evaluate MM treatment (Tx) patterns and outcomes of t(11;14)+ compared with other cytogenetic cohorts in US routine clinical practice. Methods: A retrospective observational cohort study of the Flatiron Health database, which comprises de-identified electronic health record-derived patient (pt)-level data from over 280 community and academic cancer clinics in the US. Pts aged ≥18 years who received a first-line (1L) induction Tx within ≤60 days of MM diagnosis from 1/1/2011 to 1/31/2020, and were not enrolled in a clinical trial were identified at the start of each Tx line (index date) and followed up (f/u) until 1/31/2020. Only cytogenetic results by fluorescence in situ hybridization (FISH) were used to stratify the cohort into: t(11;14)+; standard risk, excluding t(11;14)+ (SR); and high risk, (HR; del 17p, t(4;14), t(14;16), t(14;20), chromosome 1 abnormalities as a proxy for 1q gain; and t(11;14) where it co-occurs). Descriptive analyses of pt characteristics and Tx were conducted. Kaplan-Meier analyses were used to evaluate median time to next treatment (TTNT) and overall survival (OS) with log-rank test for significance. The cohort was stratified by age ≤70/>70 years (yrs) as a proxy for transplant eligibility. Results: Of 10,703 pts with MM in the database, 5982, 3059 and 1595 pts were eligible for 1L, second-line (2L), and third-line (3L) analysis, of which 76%, 84%, and 86%, respectively, had FISH test results before Tx initiation. 14% of pts with FISH test results were t(11;14)+, ~55% SR and ~35% HR. Included pts were predominately male (55%), ~90% treated in the community setting and ~16% African-American. Pts in the 3L cohort were younger at diagnosis with a median age (interquartile range) of 67 (59 ̶ 74) yrs compared with 69 (61 ̶ 76) yrs in both 1L and 2L. The 1L Tx pattern was consistent across cytogenetic cohorts with bortezomib (V), lenalidomide (R), dexamethasone (d) as the most common Tx (>42%). Together, VRd, Rd, Vd, and cyclophosphamide (Cy) in combination with Vd represented ≥90% of 1L Tx (Figure 1). Across 2L cytogenetic cohorts, the most common Tx regimens (≥25%) were VRd and Rd. The use of regimens containing carfilzomib (K) and da