Neoadjuvant chemotherapy with FOLFOXIRI for high-risk relapsed locally advanced colon cancer: A single-arm phase II trial.

201 Background: To evaluate the safety and efficacy of neoadjuvant chemotherapy (NAC) with three drug-intensity chemotherapy (oxaliplatin, irinotecan, and fluorouracil [FOLFOXIRI]) in patients with high-risk factors for recurrence and metastasis of locally advanced colon cancer (hr-LACC). Methods: A single-arm, open-label, phase II trial was conducted at West China Hospital of Sichuan University from July 2020 to Oct 2023. Patients with T4a/b or (and) N2/fused lymph nodes) and no distant metastases were considered as the hr-LACC patients. Eligible enrolled patients received four cycles of NAC with FOLFOXIRI followed by surgery and adjuvant chemotherapy with capecitabine and oxaliplatin (CAPOX) for two to five cycles or single-agent capecitabine for five cycles or observation. The primary endpoint was the rate of TRG grade 0-2 according to the criteria of NCCN guideline. Results: Of 72 patients enrolled (median age 53 [18-74] years,65 were T4a/b [90.2%], 66 were N2 [91.6%]), 58 patients (80.6%) completed four cycles of FOLFOXIRI. Three patients (4.2%) achieved clinical complete response. Twenty-eight patients (39.4%) obtained clinical partial response. The most common adverse event (AE) was nausea (86.1%, 62/72); grade 3-4 AEs occurred in 37 of 72 patients (51.4%).R0 resection was achieved in 64 of 64 patients, and the TRG (0-2) rate was 87.5% (56/64). The pathologic complete response rate was 7.8% (5/64). The proportions of pT0-2 and pN0 were 21.9% and 68.8%, respectively. Only three (4.7%) patients had prolonged hospital stay due to perioperative complications. No patient died within 30 days and 90 days after surgery. The 2-year tumor recurrence rate was 17.2%. Conclusions: For patients with hr-LACC, NAC with FOLFOXIRI regimen was safe and effective. Longer follow-up and larger clinical studies are needed to validate this innovative regimen. Clinical trial information: NCT05018182 .