Patient Characteristics And Treatment Patterns In Relapsed/Refractory Multiple Myeloma Patients After Exposure To A Proteasome Inhibitor, An Immunomodulatory Agent And Daratumumab.

e20540 Background: Many novel agents, such as a Chimeric Antigen Receptor T-Cell (CAR-T) therapy, are under investigation for the treatment of relapsed/refractory multiple myeloma (RRMM) patients (pts) who have been exposed to a proteasome inhibitor (PI), immunomodulatory drug (IMiD), and daratumumab (triple-exposed). However, limited data are available on treatment patterns in these pts. Here, we aim to study characteristics and treatment patterns after triple-exposure in RRMM pts. Methods: Data from triple-exposed RRMM pts from the Flatiron MM core registry (Jan 1, 2011 - Oct 2019) who received ≥3 prior lines of therapy (LOT) were used for the analyses. Descriptive statistics for pt characteristics and treatment patterns were assessed at end of triple exposure LOT (time T0) and after triple exposure by LOT. Results: Of the 10,011 MM pts in the Flatiron registry, 1,029 were triple-exposed; of these, 362 had a LOT after triple-exposure. Median age at T0 was 68 years and time to triple-exposure was 3.5 years from index MM diagnosis (Table). 52% were male, 81% (of 250 with available ECOG data) had ECOG status < 2, and 54% had a stem cell transplant. In 96% of pts, daratumumab was part of the triple-exposure regimen. Median follow-up from triple-exposure (LOT end date) was 7.4 months. 49% and 23% of pts had ≥2 LOTs and ≥3 LOTs after triple-exposure. Pomalidomide-, carfilzomib-, or daratumumab-containing regimens accounted for 71% and 49% of all LOT1-post-triple and LOT3 post-triple treatments, respectively; non-novel treatments accounted for 18% and 30% of LOT1 post-triple and LOT3 post-triple treatments. Conclusions: Triple-exposed RRMM pts accounted for approximately 10% of the population in the Flatiron MM core registry. Triple-exposed RRMM pts progress to multiple LOT in which they continue to be treated with PIs, IMiDs, and daratumumab; therefore, there is a need for new treatments with novel mechanisms of action for this pt population. [Table: see text]