P-90 First-line anti-EGFR agents (panitumumab or cetuximab) plus chemotherapy in patients with metastatic colorectal cancer: Onco-colon Turkey study subgroup analysis

Abdurrahman Işıkdoğan ,D Çevik,F Dane,Mehmet Ali Nahit Şendur ,Bülent Karabulut ,Ahmet Alacacıoğlu ,Timuçin Çil ,Hakan Harputluoğlu ,Hacı Mehmet Türk ,M Gümüş ,Nuri Karadurmuş ,Cemil Bilir ,Çağlayan Geredeli ,Oktay Bozkurt ,Cagatay Arslan ,Ayşegül Sakin ,Mehmet Artaç ,Umut Kefeli ,Deniz Tural ,İrfan Çiçin ,Erdem Çubukçu ,Seda Yalçın

doi:10.1016/j.annonc.2022.04.180

Abstract

The guidelines support the use of the epidermal growth factor receptor (EGFR) inhibitors panitumumab or cetuximab for the treatment of metastatic colorectal cancer (mCRC) on significant clinical benefits in patients with wild-type RAS. We assessed the efficacy and toxicity of panitumumab versus cetuximab in Onco-Colon Turkey registry patients. Patients with wild-type RAS mCRC treated with fluorouracil-oxaliplatin- and irinotecan-based chemotherapies in first-line setting were evaluated to either panitumumab or cetuximab including combinations. The efficacy of cetuximab vs panitumumab on overall survival (OS) and progression-free survival (PFS) and safety profile when combined with chemotherapy regimen was compared retrospectively. From January 2016 to March 2019, 1065 patients were recorded in Onco-Colon Turkey Registry, and 316 (47.4%) and 351(52.6%) patients were received the panitumumab and cetuximab as anti-EGFR treatment in first-line setting, respectively. The panitumumab was used more commonly with a combination regimen containing oxaliplatin (74.9%), while the cetuximab was used more in contingency with a combination regimen containing irinotecan (50.4%) (p=0.000). The median PFS was 11.6 months in the panitumumab arm and 11.0 months in the cetuximab arm, (p=0.270), and median OS was 26.5 and 27.6 months (p = 0.726), respectively. The overall response rate was 58.4% in panitumumab arm and 51.4% in cetuximab arm (p=0.138). The incidence of acneiform rash and thrombocytopenia was higher in the panitumumab arm (p=0.011 and 0.045) and the incidence of nausea/vomiting was higher in the cetuximab arm (p=0.013). Our findings show that panitumumab is similar to cetuximab and that these agents provide equal progression-free and overall survival benefit in this population of patients with wild-type RAS. Both agents had toxicity profiles that were to be expected.

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