Treatment Outcomes in Patients Receiving Regorafenib for Metastatic Colon Cancer

Objectives: To review the treatment outcomes of patients with chemorefractory metastatic colorectal cancer receiving the multikinase inhibitor regorafenib.Methods: This was a retrospective cohort study including patients who received regorafenib after failure of standard irinotecan-and oxaliplatin-based chemotherapy with or without biologics from 2016 to 2018 in a single centre in Hong Kong.Results: Fourteen patients met the inclusion criteria.All had good general condition (i.e., Eastern Cooperative Oncology Group score 1).Seven patients had received bevacizumab previously.Median progression-free survival (PFS) was 12.4 weeks and median overall survival (OS) was 26.5 weeks.Eight patients had grade ≥3 adverse events and 10 (71.4%) required temporary treatment suspension.The commonest grade ≥3 adverse events were palmarplantar erythrodysaesthesia and fatigue (both 28.6%).Patients with a carcinoembryonic antigen drop of ≥50% from baseline enjoyed longer PFS, though not to a significant extent.OS was longer for left-sided primary tumours (202 vs. 57 days, p = 0.001).Two patients with good performance after progression received trifluridine-tipiracil.Their median OS was 400 days.Conclusion: Our experience with regorafenib monotherapy for patients with chemorefractory metastatic colorectal cancer was comparable to the landmark trials.The grade ≥3 adverse events were frequent, and dose reduction or treatment delay was required.Potentially favourable prognostic factors included a left-sided primary tumour and a carcinoembryonic antigen drop from baseline.Those who received further treatment after regorafenib enjoyed reasonably long survival.Treatment after regorafenib with newer strategies should be considered in those who remain functional.