PIII trial to study panitumumab for metastatic cancer
US biotech companies Amgen and Abgenix has initiated a Phase III clinical study to evaluate the potential benefits of adding panitumumab, an experimental fully human monoclonal antibody, administered every other week to bevacizumab (Avastin, Genentech) and either oxaliplatin (Eloxatin, sanofi-aventis) or irinotecan-based (Camptosar, Pfizer) chemotherapy for the first-line treatment of metastatic colorectal cancer.
US biotech companies Amgen and Abgenix has initiated a Phase III clinical study to evaluate the potential benefits of adding panitumumab, an experimental fully human monoclonal antibody, administered every other week to bevacizumab (Avastin, Genentech) and either oxaliplatin (Eloxatin, sanofi-aventis) or irinotecan-based (Camptosar, Pfizer) chemotherapy for the first-line treatment of metastatic colorectal cancer.
The clinical trial, called the PACCE (Panitumumab Advanced Colorectal Cancer Evaluation) study, is a randomised, multi-centre, open-label study, with endpoints of progression-free survival, overall survival and response rate. Enrollment in the study of approximately 1,000 patients is already underway.
'Targeting multiple pathways that aid in tumour survival and growth at the same time or in succession theoretically has advantages over targeting one pathway alone,' said Dr Willard Dere, chief medical officer and senior vice president of global development at Amgen. 'In clinical studies to date, panitumumab appears to be well-tolerated, and interim Phase II data demonstrate that objective tumour responses in metastatic colon cancer patients occurred following panitumumab treatment.'
'We are delighted with the initiation of this important clinical trial to further explore the potential for our lead product, panitumumab, in the first-line treatment of metastatic colorectal cancer,' said Bill Ringo, president and chief executive officer at Abgenix. 'This study is a key step in the overall clinical program for panitumumab, which we expect to be evaluated with various chemotherapy agents and targeted therapies across multiple tumour types.'
Panitumumab inhibits the epidermal growth factor receptor (EGFr), while bevacizumab targets the vascular endothelial growth factor involved in angiogenesis. Although EGFr normally helps regulate the growth of many different cells in the body, EGFr can also stimulate cancer cells to grow. In fact, many cancer cells actually require signals mediated by EGFr for their survival. Residing on the surface of these tumour cells, EGFr is activated when naturally occurring proteins in the body, epidermal growth factor (EGF) or transforming growth factor alpha (TGF-alpha), bind to it. This binding changes the shape of EGFr, which, in turn, triggers internal cellular signals that stimulate tumour cell growth.
Panitumumab binds to EGFr, preventing EGF and TGF-alpha from binding to the receptor and interfering with the signals that would otherwise stimulate growth of the cancer cell and allow it to survive.
About Panitumumab
Co-developed by Amgen and Abgenix, panitumumab is an investigational product in a novel class of targeted cancer treatments called epidermal growth factor receptor (EGFr) inhibitors. Panitumumab (formerly ABX-EGF) is the first fully human monoclonal antibody directed against EGFr and is being evaluated as both a monotherapy and in combination with other agents for the treatment of various types of cancer, including colorectal, lung and kidney. Panitumumab is generated with Abgenix's XenoMouse technology, which creates a fully human monoclonal antibody that contains no murine protein. The fully human nature of panitumumab may result in a favorable safety profile with a low incidence of infusion reactions, antigenicity and allergic response. These are attributes currently being investigated in clinical trials. Pivotal clinical studies evaluating panitumumab as a third-line monotherapy in colorectal cancer patients are ongoing with an every-other-week dosing regimen.