Erlotinib add-on therapy improves outcomes in GERCOR DREAM study
MedWire News: American Society of Clinical Oncology (ASCO) Annual Meeting; Chicago, IL, USA: 1-5 June, 2012. Results from the GERCOR DREAM study show improved survival in patients with metastatic colorectal cancer who are given maintenance therapy with bevacizumab plus erlotinib over bevacizumab alone.
Cellular signaling between the epidermal growth factor receptor (EGFR) pathway and vascular endothelial growth factors (VEGFs) is known to promote tumor growth and survival; therefore, inhibition of both of these pathways should have an additive beneficial effect on tumor growth and progression.
Combining antibodies that target VEGFs and the EGFR did not improve outcomes in previous studies of patients with metastatic colorectal cancer. To try and combat this, Christophe Tournigand (Hôpital Saint-Antoine, Paris, France) and colleagues assessed the efficacy of adding an anti-EGFR tyrosine kinase inhibitor, erlotinib, to the monoclonal antibody bevacizumab, a VEGF-A inhibitor.
Tournigand reported that 446 Austrian, French, and Canadian patients with previously untreated and inoperable metastatic colorectal cancer were enrolled to take part in the phase III trial.
Patients were initially treated with FOLFOX (folinic acid, fluorouracil, and oxaliplatin; 59.4%), XELOX (capecitabine and oxaliplatin; 30.3%), or FOLFIRI (folinic acid, fluorouracil, and irinotecan; 10.3%) regimens plus bevacizumab before being randomly assigned to maintenance therapy (a median of six cycles) with bevacizumab alone (arm A; 7.5 mg/kg q 3 weeks) or bevacizumab plus erlotinib (arm B; 7.5 mg/kg q 3 weeks plus 150 mg/day, continuously).
Tournigand and his team followed the patients up for a median period of 31 months, during which 327 patients remained progression free.
Progression-free survival whilst on maintenance therapy was significantly longer by 27%, in arm B than in arm A, at 5.8 versus 4.6 months. The team notes that the study is ongoing and overall survival will be calculated as a future outcome.
Regarding adverse events, significantly more cases of grades 3/4 diarrhea and grade 3 skin toxicity occurred in erlotinib-treated patients compared with those on bevacizumab alone, at <1% versus 9%, and 0% versus 19%, respectively.
Overall, there were six severe adverse events resulting from exposure to bevacizumab in arm A and seven resulting from exposure to bevacizumab or erlotinib in arm B.
"These results suggest that erlotinib may be active in patients with metastatic colorectal cancer and provide a clinical rationale for double inhibition of VEGR and EGFR," concluded Tournigand.
MedWire (www.medwire-news.md) is an independent clinical news service provided by Springer Healthcare Limited. © Springer Healthcare Ltd; 2012
By Helen Albert