Median PFS was 3.6 (95% CI: 2–4.2), 1.7 (1.7–1.8), and 2 (1.8–2.3) months and the median OS was 7.2 (5.8–9.4), 6.3 (4.8–8), and 5.6 (3.9–7.7) months for NEXIRI, IRI, and NEX, respectively. For NEXIRI rs9344CCND1 A/A genotype patients, OS was 19.6 months (95% CI: 4.8–not reached). In patients with RASmt mCRC who progressed after standard combined chemotherapies, the results of 2-month non-progression rate and median PFS in the NEXIRI arm were in favor of an increase of the time before progression.