Anti-EGFR monoclonal antibodies for treatment of colorectal cancers: development of cetuximab and panitumumab

Over the last decade, anti-epidermal growth factor receptor (EGFR) monoclonal antibodies (mAbs) have been firmly established as essential drugs for the treatment of metastatic colorectal cancer (CRC). Cetuximab and panitumumab have been approved by American and European drug agencies. This review aims at exploring the main outcomes of clinical studies performed during their clinical development, from phase I to III trials, and hence at giving a comprehensive review of the scientific rational and up-to-date evidence sustaining the use of these drugs. Many areas are still under active investigation such as administration schedules, their efficacy in comparison with bevacizumab, their role in adjuvant therapy, molecular predictors, and management of side effects.

The role of the PI3K pathway in colorectal cancer

In the last decade treatment for colorectal cancer (CRC) has evolved with the addition of contemporary chemotherapy drugs and targeted therapies. Despite this progress, our drug armamentarium is by no means complete and modern molecular biology techniques have led to the identification of a number of 'druggable' targets. One of the most important current drug targets is the phosphatidyl-inositol 3-kinase (PI3K) pathway, which is frequently deregulated in patients with CRC. In vitro and in vivo data strongly support the clinical development of compounds affecting signal transduction via the PI3K pathway. In this review we outline the role of PI3K in the development and progression of CRC and discuss data from current and ongoing clinical trials targeting this pathway. In addition we make suggestions toward the optimization of future research in order to derive the maximum benefit for patients with CRC.