Fruquintinib Plus Checkpoint Inhibitor Combined or Sequential TAS-102 in Colorectal Cancer Patients Who Progressed on Second-line Standard Therapy: a Prospective, Multi-cohort, Single-centered, Phase Ib/II Study

Colorectal cancer (CRC) is the fourth leading cause of cancer death worldwide, claiming approximately 900,000 lives annually. In China, CRC has become one of the top three most common cancers, with about 555,000 new cases and 286,000 deaths reported in 2020. For patients with advanced metastatic colorectal cancer (mCRC), chemotherapy remains the main treatment approach. While first and second-line treatments have improved survival rates, treatment options become very limited after these initial therapies fail. Current third-line options include single-drug treatments with fruquintinib, regorafenib, or Trifluridine/Tipiracil(TAS-102). Although these medications can extend survival, their effectiveness still needs improvement. Additionally, approximately 95% of mCRC patients have a tumor type \[Proficient Mismatch Repair(pMMR)/Microsatellite Stable(MSS)\] that responds poorly to immunotherapy alone, making it crucial to find ways to expand the benefits of immunotherapy to more patients. This study aims to evaluate the effectiveness and safety of combining: Fruquintinib (a targeted therapy) Immune checkpoint inhibitors (immunotherapy) TAS-102 (oral chemotherapy)in patients with unresectable metastatic colorectal cancer who have failed standard second-line treatments. By exploring combination therapy strategies, this research hopes to improve treatment response rates, extend overall survival and provide new treatment options for patients with limited choices