Open Access
Progression‐free survival assessed per immune‐related or conventional response criteria, which is the better surrogate endpoint for overall survival in trials of immune‐checkpoint inhibitors in lung cancer: A systematic review and meta‐analysis
Author(s) -
Zhu GuangLi,
Yang KaiBin,
Tang SiQi,
Peng Liang
Publication year - 2021
Publication title -
cancer medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.403
H-Index - 53
ISSN - 2045-7634
DOI - 10.1002/cam4.4347
Subject(s) - medicine , surrogate endpoint , hazard ratio , lung cancer , clinical endpoint , oncology , progression free survival , clinical trial , cancer , chemotherapy , confidence interval
Abstract Progression‐free survival (PFS) has been used as a surrogate endpoint for overall survival (OS) in lung cancer trials. The pattern of response to immune‐checkpoint inhibitors (ICIs) differs from that to conventional chemotherapy, so immune‐related response evaluation criteria were proposed. This study aims at determining which PFS measure, PFS assessed per immune‐related response evaluation criteria (iPFS), or conventional criteria (cPFS), is the better surrogate endpoint for OS in trials of ICIs in lung cancer. We selected clinical trials in lung cancer that administered ICIs to at least one arm and reported both median OS and median PFS from PubMed, Embase, and The Cochrane Library. We compared the correlation between treatment effect (hazard ratio) on OS and cPFS or iPFS and the correlation between median OS and median cPFS or iPFS using weighted linear regression at trial level. We analyzed 78 ICI arms (13,438 patients) from 54 studies, including 66 arms with cPFS, seven arms with iPFS, and five arms with both kinds of PFS. We demonstrated an excellent correlation between treatment effect (hazard ratio) on OS and iPFS ( R WLS 2 = 0.91), while the correlation was moderate for cPFS ( R WLS 2 = 0.38). Similarly, the correlation between median OS and median iPFS was also strong ( R WLS 2 ranging from 0.86 to 0.96) across different phases of trials and different types of lung cancer, ICI, and treatment modalities, while it was much weaker for median cPFS ( R WLS 2 ranging from 0.28 to 0.88). In conclusion, iPFS provides better trial‐level surrogacy for OS than cPFS in trials of ICIs in lung cancer.