Most of the molecular-targeted cancer drugs which have entered the market recently are directed against cell membrane-bound tyrosine kinase growth factor receptors or their ligands.

Herceptin, a monoclonal antibody targeting erbB2, and Erbitux, a monoclonal antibody targeting EGFR, are both inhibitors of growth factor receptor functions on tumor cells and have been approved for advanced breast and colorectal cancer, respectively. Iressa and Tarceva, small molecules inhibiting the intracellular kinase domain of EGFR on tumor cells, were approved for the treatment of advanced non-small cell lung cancer. To date, more than 140,000 patients have received Iressa.. Furthermore, Avastin, a humanized monoclonal antibody neutralising VEGF-A, a ligand for VEGF-R on endothelial cells, was approved recently for patients with metastatic colorectal cancer.

There are more than two dozen targeted drugs in the pipelines of pharmaceutical companies. The majority of these drugs have entered phase II/III clinical trials. Also, line extensions of approved compounds will require new phase II/III trials. Here, Signature Diagnostics offers a new diagnostic approach to optimise and speed up the development of molecular-targeted approaches in close partnership with the pharmaceutical industry.