Cetuximab Plus Irinotecan in Heavily Pretreated Metastatic Colorectal Cancer Progressing on Irinotecan: MABEL Study

Purpose This large, multinational study aimed to confirm in a community practice setting the efficacy and safety of cetuximab plus irinotecan in patients with epidermal growth factor–expressing metastatic colorectal cancer (mCRC) who had recently failed an irinotecan-containing regimen. Patients and Methods The primary objective was to determine the progression-free survival (PFS) rate at 12 weeks. The initial cetuximab dose was 400 mg/m 2 and was followed weekly by 250 mg/m 2 ; irinotecan (according to prestudy regimen) was given weekly (125 mg/m 2 weekly for 4 of 6 weeks), every 2 weeks (180 mg/m 2 each), or every 3 weeks (350 mg/m 2 each). Results The intention-to-treat/safety population comprised 1,147 treated patients who received irinotecan weekly (n = 93); every 2 weeks (n = 670); every 3 weeks (n = 356); or another dose (n = 28). The PFS rate at 12 weeks was 61%, and the median survival was 9.2 months. Treatment was generally well tolerated. The most common treatment-related grades 3 to 4 adverse events were diarrhea (19%), neutropenia (10%), rash (7%), and asthenia (6%). The rate of grades 3 to 4 infusion-related reactions (IRRs; composite adverse event category) was 1% for patients who received both antihistamine and corticosteroid premedication. Conclusion Tolerability (except IRR incidence), PFS rate, and overall survival rate were in line with previous results. At 1%, the rate of IRRs in patients who received prophylactic premedication with both antihistamine and corticosteroid is lower than previously reported. MABEL clearly confirms in a community practice setting the efficacy and safety of cetuximab plus irinotecan in the treatment of mCRC.