Frailty and quality of life in a real-world multiple myeloma population.

Frailty is common in multiple myeloma (MM) and is associated with inferior outcomes. Knowledge on quality of life (QoL) primarily originates from clinical trials, where frail patients are often not included. In this nationwide, longitudinal observational study, QoL was assessed in 681 Danish patients with newly diagnosed MM (NDMM) or relapsed or refractory MM (RRMM) with symptomatic disease using patient-reported outcomes collected over 2 years of follow-up between 2017 and 2021. Patients were categorized as fit, intermediate-fit or frail according to the International Myeloma Working Group (IMWG) frailty score. Preselected QoL domains from the European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Core 30 (QLQ-C30), the Chemotherapy-Induced Peripheral Neuropathy module (EORTC QLQ-CIPN20) and the Short-form health survey (SF12) questionnaires were analysed using linear mixed models and interpreted in terms of clinical relevance. At inclusion, frail patients reported clinically relevant lower global QoL and physical functioning, and more fatigue compared to fit patients. Frail NDMM patients reported improvement in global QoL and pain during follow-up, whereas physical functioning and fatigue remained unchanged. Frail RRMM patients reported unchanged global QoL and fatigue, and deterioration in physical functioning and more pain during follow-up. Our results based on a real-world population show that QoL findings from clinical trial populations cannot directly be applied to frail patients.