Citations 1
Trial-level association between response-based endpoints (RBEs) and progression-free (PFS)/overall survival (OS) in first-line therapy for metastatic colorectal cancer (mCRC) in the ARCAD database.
Coart, Elisabeth , Saad, Everardo D. , Sommeijer, Dirkje W. , Goldberg, Richard M. , Punt, Cornelis J. A. , Douillard, Jean‐Yves , Fuchs, Charles S. , Tournigand, Christophe , Gramont, Aimery de , Burzykowski, Tomasz , Group, ARCAD, Shi, Qian , Zalcberg, John , Maughan, Tim , Schmoll, Hans‐Joachim , Cutsem, Eric Van , Hoff, Paulo M. , Tebbutt, Niall C. , Falcone, Alfredo , Sargent, Daniel J. , Buyse, Marc , Group, ARCAD, Burzykowski, Tomasz
Journal of Clinical Oncology | February 24, 2017 | Volume: 33 | Issue: 3_suppl | Pages: 666-666
10.1200/jco.2015.33.3_suppl.666
666 Background: Early tumor shrinkage (ETS; ≥20% decrease from baseline) and early objective tumor response (EOTR; CR/PR by RECIST) are associated with improved PFS/OS to a similar extent than best overall response (BOR), confirmed response (ConfR) and non-progression rate (NPR; CR/PR/SD by RECIST) at the individual level in first-line mCRC (ASCO 2014, abstr 3538/3578). We assessed these RBEs at the trial level. Methods: Data were available on 12,185 pts enrolled in a total of 17 randomized trials of chemotherapy (CT) alone or with targeted agents (TAs). ETS, EOTR and NPR were assessed at 6/8/9 and 12 weeks (wks), whereas BOR and ConfR were ascertained within 26 wks from randomization. Association between treatment effects on RBEs and on PFS/OS was assessed by coefficients of determination (R2, adjusted for estimation errors) using a copula model). Results: None of the RBEs had consistently strong correlations with PFS or OS (Table). The number of trials was insufficient to obtain reliable estimates for antiangiogenics and anti-EGFR separately. Conclusions: Despite their individual-level associations with PFS and OS, RBEs do not appear to be surrogate endpoints in first-line mCRC, given their poor predictive ability. [Table: see text]