A retrospective study of local hepatic artery infusion chemotherapy combined with regorafenib in the treatment of advanced colorectal cancer with predominant liver metastases.

e15563 Background: The hepatic arterial infusion chemotherapy (HAIC) as a second/third-line therapy has resulted in promising clinical outcomes for unresectable liver metastatic colorectal cancer (CRC). HAIC combined with regorafenib has not been reported for advanced CRC patients with predominant liver metastases. This retrospective study explored the benefits and tolerability in advanced hepatic metastatic CRC patients who received HAIC combined with regorafenib after failure of standard systemic chemotherapy. Methods: This retrospective study collected and analyzed 47 patients treated with HAIC in combination with regorafenib after standard systemic oxaliplatin and/or irinotecan in combination with Bevacizumab or Cetuximab between Jan 2017 and Jun 2020 at the Beijing cancer hospitals in China. Regorafenib was taken for 3 weeks every 4-week cycles and mostly taken 5-7 days before or after the first HAIC. The overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), and adverse events (AEs) were observed. Results: Among these 47 patients, 32(68%) were males. The median age was 61 (range: 29-75) . The median follow-up was 22.2 months (range:3.7-50.7 months). Before receiving HAIC in combination with regorafenib, 34 (72.3%) patients had previously received ≥ 2 prior lines of systemic therapy and 37 (78.7%) patients had previously received targeted biological treatment (anti-VEGF or anti-EGFR, or both).These patients underwent HAIC for a median of 4 sessions (range2--8,). The starting doses of regorafenib were 40 mg/d (n = 1, 2.13%), 80 mg/d (n = 11, 23.43%), 120 mg/d (n = 2, 4.26%), and 160 mg/d (n = 23, 48.94%). The median OS was 22.2 months. The median PFS was 10.8 (95% CI: 9.0-13.7) months. The ORR was 51.3% and DCR was 100% among 39 patients whose tumor responses were evaluated in the liver. The ORR was 13.8% and DCR was 48.3% among 29 patients whose tumor responses were evaluated outside the liver. Toxicity profile of regorafenib was as expected, with common AE were hand-foot skin reaction (12.77%), fatigue (6.38%), vomiting (6.38%), and decreased appetite (6.38%). The most common grade 3 and 4 adverse events were hand-foot skin reaction (4.26%), hypertension (2.13%), diarrhea (2.13%), and stomachache (2.13%). Only 2 patients stopped regorafenib due to AEs. Conclusions: This real-world study demonstrated that regorafenib combined with HAIC was beneficial and tolerable in advanced CRC patients with liver metastases whose disease had progressed after standard systemic therapy. It also indicated a new promising treatment strategy for late stage CRC. Additional prospective and large-scale studies are required for further confirmation. Key words: hepatic artery infusion chemotherapy; regorafenib; colorectal cancer