Final results and OS of the randomized phase II VOLFI trial (AIO- KRK0109): mFOLFOXIRI + panitumumab versus FOLFOXIRI as first-line treatment in patients with RAS wild- type metastatic colorectal cancer (mCRC).

3511 Background: This trial evaluated activity and safety of mFOLFOXIRI + panitumumab vs FOLFOXIRI in ECOG 0-1, primarily non-resectable mCRC patients. The final primary endpoint was presented at ASCO and ESMO 2018. Now we report for the first time the final results regarding OS and PFS. Methods: Prospective 2:1 randomized, controlled, open label multi-center, phase II trial comparing mFOLFOXIRI (Ox 85 mg/m2, Iri 150 mg/m2, 5-FU 3000mg/m2 cont. 48h, LV 200 mg/m2) + Panitumumab 6 mg/KG (arm A) with FOLFOXIRI (Ox 85 mg/m2, Iri 165 mg/m2, 5-FU 3200mg/m2 cont. 48h, LV 200 mg/m2; arm B), both arms q2w. Prospective strata were cohort 1: irresectable mCRC (n=65), and cohort 2: chance of secondary resection of metastatic lesions (n=31). Primary endpoint was ORR, secondary endpoints were secondary resection rate (cohort 2), DCR, PFS, OS, toxicity, quality of life (QLQ-C30). Financially supported by an unrestricted grant from Amgen. Results: A total of 96 patients were randomized (63 arm A, 33 arm B). ORR was 87.3% in arm A and 60.6% in arm B (p=0.0041, OR 4.47; 95%-CI 1.614-12.376). Secondary resections of metastases in the ITT population were observed in 33·3% (arm A Pmab) versus 12·1% (arm B) (OR=3.63; 95%-CI 1.13–11.67, p=0·029) and in cohort 2 in 75% (arm A Pmab) versus 36.4% (arm B) (OR=5.25; 95%-CI 1.07–25.8, p=0.05), respectively. Median PFS was similar in the study arms (9.7 mo in both arms, HR 1.071; 95%-CI 0.689-1.665, p=0.76). OS in the ITT population showed a strong trend in favour of the Pmab-containing arm A with a median OS of 35.7 mo compared to 29.8 mo in arm B (HR: 0·67; 95%-CI 0.41-1.11, P=0·12). mOS of cohort 2 was 52.0 mo in arm A versus 41.7 mo in arm B (HR 0.413; 95%-CI 0.15-1.12, p=0.07). Further results regarding to sidedness and BRAF mutational status will be presented. Conclusions: The addition of Pmab to a mFOLFOXIRI regimen in patients with RASwildtype metastatic colorectal cancer significantly improved objective response rate and the rate of secondary resection of metastases. Although PFS was comparable, there was a strong trend towards improved OS in the Pmab arm. Future studies are warranted to confirm this trend towards improved overall survival with this regimen. Clinical trial information: NCT01328171.