Real-world dosing patterns of regorafenib for patients with metastatic colorectal cancer in Spain: the RE-SEARCH study.

purposeTo describe the dosing patterns of regorafenib in a real-world population of patients with metastatic colorectal cancer (mCRC) in a routine clinical practice setting in Spain, focusing on the starting dose of regorafenib.

methodsAn observational, retrospective, multicenter study that included patients ≥ 18 years old who had histologically documented mCRC and who had initiated treatment with regorafenib since January 2017. Post hoc categorization of dosing patterns revealed the following: initial dose < 160 mg and dose escalation, initial dose < 160 mg and maintenance, initial dose equal to 160 mg and maintenance, and initial dose equal to 160 mg and dose reduction.

resultsMost patients (152/241, 63.8%) initiated treatment with regorafenib at doses < 160 mg. There was large variation in the starting dose of regorafenib over time: in 2017, most patients (59%) initiated regorafenib at a dose of 160 mg, this proportion decreased to 6% in 2021. There were no significant differences in the median progression-free survival according to the regorafenib dose patterns during the first two cycles. The proportion of patients who reported at least one adverse event (AE), had a grade 3-4 AE or had an AE leading to dose reduction was greater in the group of patients who received an initial dose equal to 160 and reduction.

conclusionsOur results indicate that physicians in Spain have gradually adopted a dose-escalation approach during cycle 1, which is a common practice for starting treatment with a reduced dose (< 160 mg/day), a strategy that seems to improve tolerability while maintaining efficacy.

trial registrationNot applicable.