Infusion-related reactions (IRR) associated with cetuximab plus irinotecan treatment in patients with irinotecan-resistant metastatic colorectal cancer (mCRC): Findings from the MABEL study

Abstract

4137 Background: Cetuximab is an IgG1 anti-EGFR monoclonal antibody, active alone and in combination with irinotecan in mCRC patients (pts) who have failed prior irinotecan therapy. In previous studies with cetuximab, IRRs were observed in a small proportion of pts especially at the first infusion. Methods: MABEL investigated cetuximab plus irinotecan in pts with EGFR-detectable mCRC whose last treatment regimen contained irinotecan. A secondary objective of MABEL was to further study cetuximab-related adverse events. Study treatment was cetuximab, initial dose 400 mg/m2, weekly 250 mg/m2, plus irinotecan with dose and schedule as pre-study. Data analyzed included prophylactic pre-medication, IRRs and medication for IRRs. Prophylactic medication given before the first cetuximab infusion was categorized as chlorphenamine antihistamines, antihistamines other than chlorphenamine, and any antihistamines plus corticosteroids. Results: Overall, 1147 pts were treated in this study: median age was 62 years [25–84], Karnofsky performance status was =70% and 64% pts were male. 1,122 patients were pre-treated with antihistamines. The frequency of IRRs was lower in pts who received antihistamines plus corticosteroids than in pts who received antihistamines alone (9.6% vs 25.6% any grade, 1% vs 4.7% grade 3/4 IRRs). The primary efficacy variable of MABEL was the 12-weeks progression-free survival (PFS) status. Efficacy results by pre-medication groups for PFS (see table ) and overall survival do not suggest differences related to prophylactic pre-medication. Conclusions: The data suggest that the type of pre-medication impacts on the occurrence of IRRs, and that the addition of corticosteroids to antihistamines reduces IRRs without altering antitumor efficacy in the analyzed pre-medication groups. [Table: see text] No significant financial relationships to disclose.