Comparative efficacy of later-line therapies for metastatic colorectal cancer: a network meta-analysis of survival curves

Introduction: We evaluated the comparative efficacy of six later-line (≥3) therapies for metastatic colorectal cancer (mCRC) over placebo. We applied a novel statistical method of reconstructing pseudo-patient-level data (pseudo-IPD) to inform a network meta-analysis of survival curves that considers shape in addition to scale parameters. Methods: A literature search yielded 10 phase II/III trials. We digitized all survival curves and applied a novel method incorporating curve coordinates, patients-at-risk, and events reported to generate pseudo-IPD. Using fitted random effects lognormal distributions, we estimated the survival proportions and HRs (95CrI) of progression-free (PFS) and overall survival (OS) over 12 months of follow-up. Results: Compared to placebo, in ascending order, 12-month OS HRs were 0.50 (95% CrI = 0.35, 0.69; PFS = 0.11 (95% CrI = 0.06, 0.14)) for TAS+bevacizumab; 0.71 (95% CrI = 0.51, 0.97; PFS = 0.26 (95% CrI = 0.16, 0.41)) for regorafenib; 0.75 (95% CrI = 0.61, 0.91; (PFS = 0.24 (95% CrI = 0.17, 0.31)) for TAS-102; 0.80 (95% CrI = 0.79, 0.90; PFS = 0.18 (95% CrI = 0.13, 0.24)) for fruquintinib; 0.83 (95% CrI = 0.50, 0.99; PFS = 0.42 (95% CrI = 0.20, 0.75)) for atezolizumab+cobimetinib; and 1.03 (95% CrI = 0.55, 1.65; PFS = 0.67 (95% CrI = 0.29, 1.01)) for atezolizumab. Conclusion: In this independent NMA of survival data, all later-line mCRC therapies but atezolizumab monotherapy exhibited superiority in 12-month PFS and OS over placebo. TAS+bevacizumab emerged as the most dominant option and may be the preferred choice, with fruquintinib, regorafenib, and TAS-102 monotherapy showing statistically significant but lower PFS and OS benefits. Registration: PROSPERO: CRD42022371953.