Randomized phase II trial of FOLFIRI-panitumumab compared with FOLFIRI alone in patients with RAS wild-type circulating tumor DNA metastatic colorectal cancer beyond progression to first-line FOLFOX-panitumumab: the BEYOND study (GEMCAD 17-01).

PURPOSE: Panitumumab plus FOLFOX (P-FOLFOX) is standard first-line treatment for RAS wild-type (WT) metastatic colorectal cancer. The value of panitumumab rechallenge is currently unknown. We assessed addition of panitumumab to FOLFIRI (P-FOLFIRI) beyond progression to P-FOLFOX in patients with no RAS mutations in liquid biopsy (LB). METHODS: In this randomized phase II trial, patients were assigned (3:2 ratio) to second-line P-FOLFIRI (arm A) or FOLFIRI alone (arm B). LB for circulating tumor DNA analysis was collected at study entry and at disease progression. Primary endpoint was 6-month progression-free survival. Two-stage Simon design required 85 patients to be included (EudraCT 2017-004519-38). RESULTS: Between February 2019 and November 2020, 49 patients were screened (16 RAS mutations in LB detected) and 31 included (18 assigned to arm A and 13 to arm B). The study was prematurely closed due to inadequate recruitment. Serious adverse events were more frequent in arm A (44% vs. 23%). Overall response rate was 33% (arm A) vs. 7.7% (arm B). Six-month progression-free survival rate was 66.7% (arm A) and 38.5% (arm B). Median progression-free survival was 11.0 months (arm A) and 4.0 months (arm B) (hazard ratio, 0.58). At disease progression, RAS or BRAF mutations in LB were found in 4/11 patients (36%) in arm A and 2/10 (20%) in arm B. CONCLUSIONS: The BEYOND study suggests a meaningful benefit of P-FOLFIRI beyond progression to P-FOLFOX in metastatic colorectal cancer patients with WT RAS status selected by LB. This strategy deserves further investigation.

The safety of trifluridine and tipiracil for the treatment of metastatic colorectal cancer.

INTRODUCTION: TAS102 is an oral thymidine-based nucleoside analog that has been approved for the treatment of patients with metastatic colorectal cancer (mCRC) previously treated with, or not candidates for, available therapies including fluoropyrimidine-, oxaliplatin-, and irinotecan-based chemotherapies, anti-vascular endothelial growth factor (VEGF) agents and, if RAS wild-type, anti-epidermal growth factor receptor (EGFR) therapy. The pivotal RECOURSE phase III trial demonstrated a significant improvement in disease control rate, progression-free survival (PFS), and overall survival (OS) as compared with placebo in patients with refractory mCRC. Areas covered: This manuscript aims to review the clinical development of TAS102 in CRC, with a particular focus on safety, and to provide some perspective regarding its role in clinical practice. A literature search was conducted of MEDLINE and EMBASE databases for published studies (January 2004-December 2016) using the search terms TAS102, trifluridine-tipiracil, metastatic or advanced CRC, clinical trial, toxicity, safety, pharmacology, pharmacokinetics, and therapy. Expert opinion: TAS102 significantly improves survival of patients with refractory mCRC and has manageable toxicity. An expanding role in the treatment of CRC is expected for TAS102 in the near future, as its favorable safety profile makes TAS102 a suitable drug to be combined with other cytotoxic and targeted agents.