Resection of colorectal liver metastases with second-line aflibercept plus FOLFIRI: Results from the RESECTION prospective French cohort.

Aim: To evaluate R0/R1 resection rate in patients with colorectal liver metastases (CLM) treated with aflibercept plus FOLFIRI after failure of a prior oxaliplatin-based regimen in daily clinical practice.

Methods: This French, multicentre, prospective, observational cohort (NCT05178745) included patients with CLM (alone or predominant; up to 5 lung nodules <2 cm allowed) initiating aflibercept plus FOLFIRI every 2 weeks per physician choice. Primary endpoint was R0/R1 resection rate. Secondary endpoints included overall survival (OS), progression-free survival (PFS), radiological and pathological responses, and safety.

Results: A total of 137 patients (median age 65 years, RAS/BRAF mutant 57 %/9 %) were enrolled at 22 French sites. CLM (median 4) were synchronous in 82 %, bilobar in 71 % and located in liver only in 54 %. Overall, 17 % of patients had R0/R1 resection (21 % for patients with liver-only disease). A major pathological response per Blazer score was observed in 55 % of resected patients, along with significantly longer OS (median 34.8 vs 9.1 months, p < 0.0001) and PFS (median 11.4 vs 4.9 months, p < 0.0001) compared to non-resected patients. Post-operative complications occurred in 17 % of patients (all Dindo-Clavien grade I-II) and there was no post-operative deaths. Overall, 34 % had grade ≥ 3 adverse events, mainly general health deterioration and diarrhea.

Conclusions: Results suggest that aflibercept plus FOLFIRI, after failure of a prior oxaliplatin-based regimen, allows R0/R1 resection of CLM in almost 20 % of patients with a major pathological response in most cases and a median OS prolonged by more than 3-fold versus non-resected patients.