Efficacy and tolerability of second-line intra-arterial 5FU or mitomycine C after intra-arterial oxaliplatin failure in patients with colorectal cancer and unresectable liver metastases

e15061 Background: Hepatic arterial infusion (HAI) chemotherapy of oxaliplatin is an option in the management of metastatic colorectal cancers (mCRC) with dominant liver metastases (LM). However, despite prolonged control some patients (pts) experience disease progression or dose-limiting toxicity. In these cases, the use of a second-line HAI with an alternative drug has never been reported to date. This pilot study is evaluating treatment outcomes in pts receiving HAI of 5-FU or mitomycine C (MMC), after HAI oxaliplatin (HAI-ox) in heavily pretreated pts. Methods: 24 pts with unresectable mCRC were enrolled, metastases were exclusively or dominant in the liver (≥80% of overall total metastatic tumour burden in the liver), all pts received prior HAI-ox. They were treated with either biweekly HAI 5-FU with dose ranging from 600 to 1200mg/m2 over 2 hours (17 patients), or monthly MMC 7mg/m2 over 1 hour (7 patients). Results: Mean age was 62 years. 42% of pts (10/24) had extra-hepatic metastases and 75% (18/24) had 8 LM or more. Including prior HAI-ox, pts had previously received a median of 3 prior lines of treatment (range:2 to 5). Previous HAI-ox was stopped for toxicity in 17 pts (allergy, neuropathy or abdominal pain) or progression in 7 pts. At baseline, 62% of pts had progressive disease. All pts but one received concomitant systemic therapies together with HAI 5FU or MMC. The overall RECIST V1.1 objective response rate and disease control rate were respectively 42% (10/24) and 71% (17/24). Median progression free survival (PFS) and overall survival (OS) were respectively 5.6 and 25.8 months; hepatic PFS was 8.5 months. 3 pts benefited from further curative intent treatments after 2nd line HAI (2 radiofrequency, 1 surgery). No toxic death occurred and toxicity profile was acceptable, with only 2 grade 3 events reported (diarrhea and thrombocytopenia). Conclusions: 2nd line HAI with 5-FU or MMC seems feasible and efficient in heavily pretreated mCRC with liver dominant disease when progressing or not tolerating oxaliplatin HAI. A phase II study is going to be performed to confirm these first results.