Panitumumab plus trifluridine/tipiracil as anti-Epidermal Growth Factor Receptor rechallenge therapy in chemo-refractory RAS wild-type metastatic colorectal cancer: the randomized phase 2 VELO trial

Current therapies for chemo-refractory metastatic colorectal cancer (mCRC) have limited efficacy. Rechallenge with epidermal growth factor receptor (EGFR) inhibitors in RAS wild-type (WT) mCRC could be valuable in this setting. In VELO, a randomized two-arm phase 2 trial, anti-EGFR monoclonal antibody panitumumab plus standard-of-care trifluridine/tipiracil (31 patients, arm B) was compared to trifluridine/tipiracil (31 patients, arm A) as third-line therapy (ClinicalTrials.gov Identifier NCT05468892). Primary endpoint, progression-free survival (PFS), was met. Median PFS was 4.0 months in arm B versus 2.5 months in arm A [hazard ratio (HR): 0.48; 95% CI 0.28–0.82; P = 0.007]. Baseline plasma RAS/BRAF WT circulating tumor DNA identified patients obtaining prolonged clinical benefit with panitumumab plus trifluridine/tipiracil as compared to trifluridine/tipiracil with PFS rates at 6 months of 38.5% versus 13% and at 12 months of 15.4% versus 0%, respectively. These findings warrant further development for liquid biopsy-guided anti-EGFR rechallenge combination strategies in chemo-refractory RAS WT mCRC.