Randomized phase-II trial of surufatinib plus FOLFOX/FOLFIRI versus FOLFOXIRI as second-line therapy for metastatic colorectal cancer.

Second-line treatment for metastatic colorectal cancer (mCRC) typically involves oxaliplatin- or irinotecan-based doublet chemotherapy with or without anti-angiogenic antibodies. Triplet regimens such as FOLFOXIRI have demonstrated synergy and improved efficacy as first-line therapy. Surufatinib, an oral multi-kinase inhibitor targeting VEGFR1-3, FGFR1, and CSF-1R, may enhance chemotherapy efficacy. We evaluated surufatinib combined with doublet (FOLFOX/FOLFIRI) versus triplet (FOLFOXIRI) chemotherapy as second-line treatment for mCRC.

This multicentre, open-label, randomized phase-II trial used Simon's minimax two-stage design. Eligible patients had mCRC progressing on or within 6 months after first-line doublet chemotherapy. Patients were randomized 1:1 to surufatinib 250 mg once daily plus either mFOLFOX6/FOLFIRI (doublet cohort, selected based on prior regimen) or FOLFOXIRI (triplet cohort). The primary endpoint was objective response rate (ORR).

From September 2021 to November 2023, 57 patients were randomized (28 per cohort after one withdrawal). In the doublet cohort, ORR was 35.7% (95% CI: 18.6-55.9), median progression-free survival (PFS) was 5.4 months (95% CI: 3.8-7.0), and median overall survival (OS) was 19.0 months (95% CI: 9.2-28.8). In the triplet cohort, ORR was 39.3% (95% CI: 21.5-59.4), median PFS was 5.8 months (95% CI: 3.3-8.2), and median OS was 10.9 months (95% CI: 6.0-15.8). Grade ≥3 treatment-emergent adverse events occurred more frequently in the triplet (71.4%) versus doublet (57.1%) cohort, with higher rates of treatment delays (89.3% versus 72.0%) and discontinuations (25.0% versus 14.3%).

Surufatinib plus doublet chemotherapy showed encouraging antitumor activity and acceptable tolerability in second-line mCRC, warranting further evaluation in a larger randomized trial. In contrast, surufatinib plus triplet chemotherapy was associated with increased toxicity, more frequent treatment delays or discontinuations, and shorter overall survival; this combination is not recommended for further investigation in this setting.ClinicalTrials.gov: NCT04734249Date of registration: January 31, 2021. Surufatinib plus doublet chemotherapy achieved promising efficacy and tolerability in second-line metastatic colorectal cancer, with ORR 35.7%, median PFS 5.4 months, and median OS 19.0 months.Surufatinib plus triplet chemotherapy (FOLFOXIRI) offered no clear advantage over the doublet regimen and was limited by greater toxicity and inferior overall survival.