Real-World Study Of Treatment Patterns In Heavily Pretreated Relapsed/Refractory Multiple Myeloma (Rrmm) In The Us

Context Real-world data on treatment patterns and outcomes in patients with RRMM resistant to multiple drug classes are limited. Objective To assess clinical treatment patterns and refractory status in patients with RRMM. Methods This longitudinal retrospective cohort study utilized the COTA de-identified real-world database derived from US electronic medical records of partnered healthcare providers from Q3 1988 through Q1 2020; 650 adults with active RRMM previously exposed to ≥1 proteasome inhibitor (PI) and 1 immunomodulatory drug (double-exposed) and who received ≥3 prior lines of therapy (LOTs) were identified. Patients were further categorized as refractory to a PI and an immunomodulatory drug (double-class refractory [DCR]; n=381) or additionally to an anti-CD38 monoclonal antibody (i.e., daratumumab; triple-class refractory [TCR]; n=173). Index LOT was the fourth (double-exposed) or new LOT after evidence of DCR or TCR status following ≥3 or ≥4 prior LOTs (DCR or TCR, respectively). Median follow-ups from index LOT initiation through end of data availability/death were 24 (double-exposed), 14 (DCR), and 8 (TCR) months. Assessments included therapies received before/during the index LOT, duration of treatment (DOT), and treatment discontinuation reasons. Results Patient characteristics included age ≥65 years (49% DCR; 53% TCR), International Staging System stage III (14%; 16%), and high-risk cytogenetics (56%; 66%); >62% had prior autologous stem cell transplantation. Patients had a median of 3 (DCR) and 6 (TCR) prior LOTs. Retreatment percentages among DCR patients were 60% (PI) and 69% (immunomodulatory drug); 30% were exposed to daratumumab. For TCR patients, retreatment percentages were 65% (PI), 60% (immunomodulatory drug), and 29% (daratumumab). Median DOTs were 3.3 (DCR) and 2.8 months (TCR). Patients discontinued index therapy most commonly due to disease progression (59% DCR; 60% TCR) or toxicity (23%; 24%). After index LOT, 70% DCR and 58% TCR patients continued to a subsequent LOT. Conclusions Treatment options are limited for US patients with heavily pretreated RRMM. DCR/TCR patients were frequently retreated with a PI, immunomodulatory drugs, or daratumumab (TCR patients) despite refractoriness to these agents. Many DCR/TCR patients stopped active MM treatment after discontinuing index treatment. Funding GlaxoSmithKline (212953).