Treatment Pattern, Healthcare Resource Utilization and Symptom Burden Among Patients with Triple Class Exposed Multiple Myeloma: A Population-Based Cohort Study

Purpose This study aims to describe the treatment patterns, outcomes, health care utilization and symptom burden of triple class exposed (TCE) relapsed/refractory patents with multiple myeloma (MM) receiving a subsequent line of treatment (LOT). Methods This is a retrospective observational cohort study using administrative databases in Ontario, Canada. Outcomes were captured for TCE patients receiving a subsequent LOT and included: treatment regimen details, time to next treatment (TTNT), overall survival (OS), health care utilization, palliative care referral, and patient reported symptoms. Results Of the 16,777 patients diagnosed with MM between 2007-2021 in Ontario, 1358 (8%) patients were classified as TCE. Among the TCE MM patients, 489 (36%) received a subsequent LOT. The two most commonly administered therapies post TCE were carfilzomib/dexamethasone (n = 111, 22%) and pomalidomide/dexamethasone(n = 95, 19%). Median TTNT was 1.7 months (95%CI 1.2-2.4 months) and median OS 12.8 months (95%CI 10.8-16.5). Healthcare utilization was high with 276 (56%) of patients evaluated in an emergency department (ED) or admitted to hospital. There was high symptom burden as reported by patients with moderate-severe impairment in well-being, fatigue, pain and drowsiness noted in greater than 25% of the cohort. Palliative care referrals rates were low with only 10% (n = 48) patients referred to palliative care. Among the patients that died during study follow up, the majority died in hospital (n = 147,44%). Conclusion Our study reports one of the largest series of real-world TCE patients published and demonstrates the poor outcomes of TCE patients receiving a subsequent LOT.