Symptomatic progression-free survival as an emerging patient-centered endpoint in multiple myeloma: a secondary analysis of MagnetsiMM-3 trial data

There is a need to better reflect the patient experience in multiple myeloma (MM), beyond just clinical progression, with the use of a novel endpoint that combines disease progression with patient-reported outcomes. A systematic literature review (SLR) identified relevant MM symptoms, which were narrowed down by experts using a Delphi panel. A post-hoc analysis of the MagnetisMM-3 trial of elranatamab assessed the impact of change in patient-reported outcomes (PROs) on the risk of disease progression or death. A composite endpoint for symptomatic progression-free survival (SPFS) combined these symptoms and PFS (PFS event plus 10-point worsening in pain, fatigue, or poor mobility within 28 days). The SLR identified 16 symptoms from 34 publications. Delphi consensus was that drowsiness, fatigue, pain, and poor mobility are linked to disease progression. Three symptoms had a significant association with PFS: A 10-point worsening on the 100-point scales for pain, fatigue, and poor mobility corresponded to a 22%, 20%, and 31% increase in risk of progression, respectively. Median SPFS was not reached (95% CI 12.2- not reached). SPFS is the first composite endpoint in MM that combines PFS and clinically relevant PROs. The patient-centric approach in the conception of this endpoint allows for a nuanced and comprehensive understanding of the MM patient experience.