The EPOCH trial: Identifying key patient subgroups to optimize treatment planning.

Abstract

130 Background: The primary objective of the original EPOCH trial was to evaluate the potential benefit of adding transarterial radioembolization (TARE) with yttrium-90 glass microspheres to second-line chemotherapy (chemo) versus chemo alone in patients with liver-dominant metastatic colorectal cancer (mCRC). Randomization was stratified by key prognostic factors, including KRAS status; however, it did not account for ECOG status and baseline CEA levels. We present post-hoc analyses investigating the impact of prognostic factors on primary and secondary endpoints to help optimize patient selection. Methods: EPOCH was a 1:1 randomized, open-label, global, multicenter Phase 3 trial. Primary endpoints were progression-free survival (PFS) and hepatic PFS (hPFS). Overall survival (OS) and time to deterioration of quality of life (TTDQOL) were secondary. Post-hoc analyses of the following subgroups were performed: Subgroup A (excluding patients with both ECOG=1 and CEA≥35ng/mL) and Subgroup B (patients with KRAS wild-type and either ECOG=0 or CEA<35ng/mL). Kaplan-Meier analyses, hazard ratios (HRs) and log-rank tests were used to compare outcomes between TARE plus chemo and chemo only groups. Results: In Subgroup A, 160 (75.1%) patients were randomized to chemo only, versus 143 (66.5%) to the TARE arm. In Subgroup B, 91 (42.7%) patients were randomized to chemo only, versus 77 (35.8%) to the TARE arm. Results are shown for PFS, hPFS, OS, and TTDQOL in the intent-to-treat population. In both subgroups A and B, PFS, hPFS, and TTDQOL were significantly improved for the TARE plus chemo arm as compared to the chemo only arm; no OS difference was found. Conclusions: Careful patient selection using multiple prognostic factors is necessary to identify those who will benefit most from TARE with second-line chemo. Prognostic factors were important in identifying the level of benefit seen in patients treated with TARE and chemo versus chemo alone. Clinical trial information: NCT01483027 . [Table: see text]