Randomized phase II trial of adjuvant hepatic arterial infusion (HAI) + systemic FOLFIRI +/- panitumumab (Pmab) in patients with resected RAS wild type colorectal cancer hepatic metastases (CRLM).

Abstract

3555 Background: HAI therapy has improved recurrence free (RF) survival in several randomized trials after resection of CRLM. The purpose of this trial was to determine whether systemic Pmab added to adjuvant HAI + FOLFIRI in RAS WT pts increases 15 months RF survival (RFS) after liver resection. Secondary endpoints are evaluation of overall survival, toxicity, and predictive biomarkers. Methods: RAS WT pts with resected liver mets were randomized to HAI + SYS (+/-) Pmab after stratification by clinical risk score (≥ 3 or < 3) and previous chemotherapy (Y/N). For a particular arm, if 24 or more patients (pts) were alive and RF at 15 months, the regimen in that arm would be considered worthy of further investigation. The initial dose of HAI FUDR 0.12mg/Kg + dexamethasone was infused over the first 2 weeks of a 5-week cycle. Systemic chemotherapy was delivered on days 15 and 29 (irinotecan 125 mg/m2, LV 400 mg/ m2, 5FU 1000 mg/m2 48-hour continuous infusion and +/- Pmab 6mg/kg). Patient characteristics were compared between arms using Fisher’s exact test and Wilcoxon rank-sum test. Survival curves were estimated using the Kaplan-Meier method and compared by the log-rank test. Results: After randomization of 75 pts, the arm receiving + Pmab met the decision rule of having ≥ 24 patients alive and RF at 15 months. The two arms had similar pt characteristics and toxicity, with the exception of Pmab related rash (Table). The 15-month RFS is 79% and 67% in +/- Pmab arms, respectively. With a median follow-up of 45 months, 3-year RFS is 65% [CL 0.45-0.78] and 42% [CL 0.24-0.57], and 3-year survival is 96% and 90% in +/-Pmab arms, respectively. Conclusions: In this trial, the addition of Pmab to HAI and SYS showed promising activity without increase in biliary toxicity and should be further investigated in a larger study. Predictive biomarkers will be presented. Clinical trial information: NCT01312857. [Table: see text]