Real-World Study of Patients with Metastatic Colorectal Cancer and Long-Term Response to Regorafenib in the USA

Background: Several narrative reports document long-term responses to regorafenib treatment in patients with metastatic colorectal cancer (mCRC). However, no large-scale study has assessed long-term responses and there are no established predictors of potential long-term benefit. We carried out an observational study of characteristics of patients treated in real-world clinical practice in the USA using duration of treatment (DoT) as a surrogate for treatment response. Patients and Methods: This retrospective cohort study used a de-identified electronic health record-derived database and included patients aged ≥18 years with mCRC who initiated regorafenib monotherapy between 1 July 2013 and 30 June 2023. Patient cohorts were defined by DoT ≥4 months (LTR4), ≥5 months (LTR5), or ≥6 months (LTR6) and are not mutually exclusive. Results: Of 2444 patients who initiated regorafenib monotherapy during the study, those with long-term response were analyzed: 544 had LTR4 (22%), 367 had LTR5 (15%), and 250 had LTR6 (10%). Most patients with long-term responses had left-sided tumors (65–70%), Eastern Cooperative Oncology Group performance status of 0/1 (67–68%), and liver metastases (55–61%) and had received prior bevacizumab treatment (60–67%). The median age in each group was 66 years, and patients most frequently initiated regorafenib as third-line treatment (31–33%). Median time to regorafenib discontinuation was 6.0–9.3 months among long-term responders. Conclusion: Most patients with long-term responses to regorafenib had favorable performance status at treatment initiation, left-sided tumors, and liver metastases and had received prior bevacizumab treatment. The study highlights that patients in the real-world setting were able to tolerate and maintain long-term responses to regorafenib treatment.