Beyond progression-free survival (PFS): time to next treatment (TTNT) as a patient-centered metric of clinical benefit in chronic lymphocytic leukemia (CLL)

The analysis suggests that TTNT enriches the CLL endpoint repertoire by capturing patient-centered outcomes and informing pragmatic clinical decision-making. Nevertheless, regulatory and methodological standards advocate a two-tier validation approach that includes both individual patient-level analyses and trial-level validation. TTNT in CLL should complement, but not substitute for, PFS in evaluating therapeutic benefit and guiding clinical decision-making.