Efficacy and safety of fruquintinib plus sintilimab in third-line treatment of metastatic colorectal cancer: A single-center experience

Abstract

BACKGROUND

There are few drugs available for the third-line treatment of metastatic colorectal cancer (mCRC), and efficacy is generally poor. Fruquintinib, an anti-vascular endothelial growth factor receptor tyrosine kinase inhibitor, has been approved for mCRC; however, its efficacy as a single agent is not satisfactory. Most patients with mCRC are microsatellite stable (MSS), and not sensitive to immunotherapy. The combination of fruquintinib and immunotherapy may improve the survival of patients with mCRC.

AIM

To report the real-world experience using this combination therapy for MSS mCRC in routine clinical practice.

METHODS

The medical records of six patients with MSS mCRC who received third-line treatment with fruquintinib plus sintilimab between January 2022 and June 2024 were retrospectively reviewed. Survival analysis was performed using the Kaplan-Meier method.

RESULTS

One patient achieved a complete response, one had stable disease, and four experienced progressive disease. Median progression-free survival was 3.8 months, and median overall survival was 5.7 months. Common adverse reactions included bone marrow suppression, liver function impairment, and hypothyroidism, predominantly grades 1-2, with no grade 4 adverse reactions reported.

CONCLUSION

Our single-center experience in a small cohort implies fruquintinib combined with sintilimab may be efficacious and safe for select patients in the third-line treatment of mCRC. This combination therapy warrants further exploration.

Keywords: Metastatic colorectal cancer; Third-line treatment; Fruquintinib; Sintilimab; Immunotherapy; Prognosis

Core Tip: This study evaluated the safety and efficacy of fruquintinib plus sintilimab in third-line treatment of metastatic colorectal cancer (mCRC). One patient achieved complete response, one had stable disease, and four experienced progressive disease. Median progression-free survival was 3.8 months, and median overall survival was 5.7 months. Fruquintinib combined with sintilimab was well tolerated. Common adverse reactions included bone marrow suppression, liver function impairment, and hypothyroidism, predominantly grades 1-2. Fruquintinib combined with sintilimab as a third-line treatment for mCRC appeared effective in patients with microsatellite stable mCRC and a low tumor burden, who experienced a survival benefit. This treatment warrants further exploration.