[Correspondence] The GLOW trial in chronic lymphocytic leukaemia – Authors’ reply

Michel van Gelder and colleagues and Martin Fey provided relevant questions regarding the GLOW trial 4-year follow-up.1 Fey asks whether progression-free survival is a clinically valid outcome for frail patients with chronic lymphocytic leukaemia (CLL), and why more patient-related and health-care-related outcomes, primarily quality-of-life (QoL) and cost-effectiveness analyses were absent. A discussion on proxy outcomes is valid and is an ongoing discussion engaging health authorities, patient representatives, and clinicians.