Authors: Hideaki Bando, Eiji Oki, Yuriko Takeda, Toshihiro Misumi, Motoko Suzuki, Masashi Wakabayashi, Kentaro Yamazaki, Axel Grothey, Robert J. Mayer, Jin Li, Thierry Andre, Qian Shi, Aimery De Gramont, Takayuki Yoshino
Published: 2024-01-22
DOI: 10.1200/jco.2024.42.3_suppl.115
Source: Full article
115 Background: Randomized clinical trials provide the best evidence for the effects of a new treatment. However, the use of a placebo control arm may present practical and ethical concerns for enrolled patients and treating providers. The CRC ARCAD global database includes a total of 1,673 individual patient data (IPD) treated with placebo plus best supportive care in a salvage-line setting for refractory mCRC. By using placebo IPD, we have proposed to construct a synthetic control arm for clinical trials (Yoshino T. et al., Nature Medicine 2023). Methods: From 40,889 IPD from 59 studies in ARCAD mCRC database, 723 placebo pts were selected from 4 placebo-controlled randomized studies in a salvage-line setting (CORRECT, RECOURSE, CONCUR and TERRA). We analyzed the impact of baseline patient characteristics and various prognostic factors on outcome in the placebo control. Results: The adjusted hazard ratios (HRs) (95% confidence interval [CI]) were 0.52 (0.40-0.67) for the number of metastatic sites (1 vs 2+), 0.71 (0.59-0.84) for ECOG performance status (PS) (0 vs 1), 0.54 (0.45-0.66) for liver metastases (No vs Yes), 0.54 (0.40-0.71) for peritoneal metastases (No vs Yes), and 0.51 (0.38-0.70) for Royal Marsden Hospital (RMH) Score (consisting of albumin level, number of metastatic sites, and LDH level) (0-1 vs 2-3). Conclusions: Number of metastatic sites, ECOG PS, liver metastasis, peritoneal metastasis and RMH Score were significant prognostic factors in patients with mCRC receiving placebo in a salvage-line setting. Further prognostic factors should be investigated to increase the accuracy of the proposed synthetic control arm. [Table: see text]