PURPOSE: Cetuximab, a chimeric immunoglobulin G 1 (IgG1) anti-epidermal growth factor receptor (EGFR) monoclonal antibody (mAb), has shown efficacy in 10% of patients with metastatic colorectal cancer (CRC). Recent studies demonstrate antibody-dependent cell-mediated cytotoxicity (ADCC) is one of the modes of action for rituximab and trastuzumab. Fragment c (Fc) portion of IgG1 mAb has shown to induce ADCC. Fragment c gamma receptors (FcgammaR) play an important role in initiating ADCC. Studies have shown that two IgG FcgammaR polymorphisms (FCGR2A-H131R and FCGR3A-V158F) independently predict response to rituximab in patients with follicular lymphoma. We tested the hypothesis of whether these two polymorphisms are associated with clinical outcome in metastatic CRC patients treated with single-agent cetuximab. PATIENTS AND METHODS: Thirty-nine metastatic CRC patients were enrolled onto the ImClone0144 trial. Using an allele-specific polymerase chain reaction (PCR) -based method, gene polymorphisms of FCGA2A-H131R and FCGA3A-V158F were assessed from genomic DNA extracted from peripheral blood samples. RESULTS: FCGR2A-H131R and FCGR3A-V158F polymorphisms were independently associated with progression-free survival (PFS; P = .037 and .055, respectively; log-rank test). Combined analysis of these two polymorphisms showed that patients with the favorable genotypes (FCGR2A, any histidine allele, and FCGR3A, any phenylalanine allele) showed a median PFS of 3.7 months (95% CI, 2.4 to 4.4 months), whereas patients with any two unfavorable genotypes (FCGR2A arginine/arginine or valine/valine) had a PFS of 1.1 months (95% CI, 1.0 to 1.4 months; P = .004; log-rank test). CONCLUSION: Our preliminary data suggest that these two polymorphisms may be useful molecular markers to predict clinical outcome in metastatic CRC patients treated with cetuximab and that they may indicate a role of ADCC of cetuximab.
PURPOSE:Cetuximab, a chimeric immunoglobulin G 1 (IgG1) anti-epidermal growth factor receptor (EGFR) monoclonal antibody (mAb), has shown efficacy in 10% of patients with metastatic colorectal cancer (CRC). Recent studies demonstrate antibody-dependent cell-mediated cytotoxicity (ADCC) is one of the modes of action for rituximab and trastuzumab. Fragment c (Fc) portion of IgG1 mAb has shown to induce ADCC. Fragment c gamma receptors (FcgammaR) play an important role in initiating ADCC. Studies have shown that two IgG FcgammaR polymorphisms (FCGR2A-H131R and FCGR3A-V158F) independently predict response to rituximab in patients with follicular lymphoma. We tested the hypothesis of whether these two polymorphisms are associated with clinical outcome in metastatic CRCpatients treated with single-agent cetuximab. PATIENTS AND METHODS: Thirty-nine metastatic CRCpatients were enrolled onto the ImClone0144 trial. Using an allele-specific polymerase chain reaction (PCR) -based method, gene polymorphisms of FCGA2A-H131R and FCGA3A-V158F were assessed from genomic DNA extracted from peripheral blood samples. RESULTS:FCGR2A-H131R and FCGR3A-V158F polymorphisms were independently associated with progression-free survival (PFS; P = .037 and .055, respectively; log-rank test). Combined analysis of these two polymorphisms showed that patients with the favorable genotypes (FCGR2A, any histidine allele, and FCGR3A, any phenylalanine allele) showed a median PFS of 3.7 months (95% CI, 2.4 to 4.4 months), whereas patients with any two unfavorable genotypes (FCGR2A arginine/arginine or valine/valine) had a PFS of 1.1 months (95% CI, 1.0 to 1.4 months; P = .004; log-rank test). CONCLUSION: Our preliminary data suggest that these two polymorphisms may be useful molecular markers to predict clinical outcome in metastatic CRCpatients treated with cetuximab and that they may indicate a role of ADCC of cetuximab.
Authors: Sara A Hurvitz; David J Betting; Howard M Stern; Emmanuel Quinaux; Jeremy Stinson; Somasekar Seshagiri; Ying Zhao; Marc Buyse; John Mackey; Adrian Driga; Sambasivarao Damaraju; Mark X Sliwkowski; Nicholas J Robert; Vicente Valero; John Crown; Carla Falkson; Adam Brufsky; Tadeusz Pienkowski; Wolfgang Eiermann; Miguel Martin; Valerie Bee; Omkar Marathe; Dennis J Slamon; John M Timmerman Journal: Clin Cancer Res Date: 2012-04-13 Impact factor: 12.531
Authors: Rodney J Taylor; Vassiliki Saloura; Ajay Jain; Olga Goloubeva; Stuart Wong; Shari Kronsberg; Madhavi Nagilla; Lorna Silpino; Jonas de Souza; Tanguy Seiwert; Everett Vokes; Victoria Villaflor; Ezra E W Cohen Journal: Cancer Immunol Res Date: 2015-03-13 Impact factor: 11.151