Safety of fruquintinib in Chinese patients with colorectal cancer: an age subgroup analysis from a phase IV real-world clinical practice study.

Background: Colorectal cancer (CRC) is increasingly prevalent among young adults (<50 years) in China, a demographic that has been historically underrepresented in clinical studies. While most patients with CRC are aged ⩾65 years, this age group is also underrepresented in trials, highlighting the need for a better understanding of treatment outcomes in both younger and older populations. A recent phase IV trial evaluating the safety of fruquintinib in Chinese patients with metastatic CRC (mCRC) showed a manageable profile. Objectives: This subgroup analysis of the phase IV study primarily aims to evaluate the safety of fruquintinib in different age groups. Design: Prospective real-world study. Methods: The data of patients with CRC from the phase IV fruquintinib trial (NCT04005066) were collected for the young (<50 years) and the late elderly (⩾75 years) patients with CRC who were enrolled between April 24, 2019, and September 27, 2022. The safety outcomes, including treatment-emergent adverse events (TEAEs) and treatment-related adverse events (TRAEs), were recorded. Results: A total of 2798 patients with CRC enrolled in the phase IV study were categorized into two subgroups: 512 were young (age <50), and 239 were late elderly (age ⩾75). The young CRC subgroup received more intense treatment with a median treatment duration of 2.75 months, and the late elderly received a median treatment duration of 2.40 months. Combination therapy duration was longer than that of monotherapy in young (4.10 vs 2.40 months) and late elderly patients (3.90 vs 2.10 months). The incidence of TEAE was comparable across the young (78.71%) and the late elderly groups (77.41%). In the young CRC subgroup, the most common TRAEs were palmar-plantar erythrodysesthesia ((PPES) 20.31%) and hypertension (14.06%), whereas in the late elderly, they were hypertension (20.50%) and PPES (14.23%). Conclusion: The safety profile of fruquintinib was comparable across age subgroups. Young CRC patients tend to receive more intensive fruquintinib treatment. For the late elderly, who are more susceptible to TRAEs due to underlying health conditions, fruquintinib also offers a safe treatment option. Combination therapy duration was longer than monotherapy in both subgroups, suggesting its promising approach for optimizing treatment outcomes in both age subgroups.