Time to deterioration of patient-reported outcomes as a surrogate of overall survival: meta-analysis

Overall survival (OS) is the optimal marker of efficacy of treatments, but can take a considerable amount of time. Progression-free survival (PFS) has served as an early surrogate of OS, but is imperfect. A meta-analysis of 138 phase 3 randomized trials evaluated time to deterioration (TTD) of quality of life (QOL) or physical function (PF) as surrogate of OS. TTD QOL and TTD PF performed similarly to PFS as surrogates of OS. For ICI studies, TTD PF had a higher association with OS compared to PFS. The combination of TTD PF and PFS in ICI studies enabled better prediction of OS than either PFS or TTD PF alone.