e15053 Background:The role of combination chemotherapy plus anti-EGFR treatment in older patients with metastatic colorectal cancer (mCRC) is unclear. We conducted an open label phase II trial in order to evaluate the safety and efficacy of modified FOLFIRI plus panitumumab as first-line treatment in elderly patients with RAS wild-type mCRC. Methods: Patients ≥70 years old with unresectable all-RAS wild-type mCRC were treated with Panitumumab 6mg/kg as 60min iv infusion followed by Irinotecan 130mg/m2 as 90min iv infusion, Leucovorin 400mg/m2 as 2h iv infusion and 5-Fluorouracil 400mg/m2 as bolus iv infusion on day 1 and 5-Fluorouracil 1.200 mg/m2 as continuous iv infusion for 46h, every 2 weeks. Sample size calculation was based on the minimax Simon two-step design: The null hypothesis was that the overall response rate (ORR) is ≤ 30% versus the alternative hypothesis of ORR ≥ 50% (α = 0.05, power 80%). Results: Forty-six patients were enrolled in the study. Two patients did not receive treatment because they were RAS mutant. Median age for the 44 treated patients was 76 years (range 70-88). Males were 32 and the PS was 0, 1 and 2 in 25%, 70.5% and 4.5% of patients, respectively. Rectal cancer accounted for 25% while 15.9% of patients had the primary tumour in situ. Twenty-one partial responses were observed for an ORR of 47.7% (95%CI: 32.9%-62.5%) while seven patients (15.9%) had stable disease. After a median follow-up of 36.0 months, the median progression-free survival was 6.1 months (95%CI: 3.6-8.7) and the median overall survival was 20.9 months (95%CI: 11.7-30.1). Grade 3-4 neutropenia was recorded in 4 (9%) and grade 3-4 diarrhea in 9 (20.4%) patients while one patient had a grade 4 bowel perforation. One patient experienced grade 3 mucositis, two patients grade 3 skin toxicity and two patients grade 3 fatigue. There were no toxic deaths while one patient died due to bowel obstruction and one due to postoperative complications after removal of the primary tumor. Conclusions: The modified FOLFIRI plus panitumumab combination presented significant efficacy with manageable toxicity in elderly patients with mCRC.
First-line single-agent panitumumab in frail elderly patients with wild-type RAS unresectable colorectal cancer: a phase II study protocol OGSG 1602
