I just recently wrote a post (here) that describes how I became convinced that under certain circumstances there could be a genuine value in determining whether a particular lung cancer patient has a tumor with an EGFR activating mutation.
There are two widely tested epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) -- iressa (gefitinib) and tarceva (erlotinib).
We’ve been following sorafenib (nexavar), a multi-kinase inhibitor with anti-angiogenic activity (see prior post). This oral agent, which is already approved as an effective treatment for cancers of the liver and kidney.
One of my earliest posts when I started OncTalk was on the use of oral inhibitors of the epidermal growth factor receptor (EGFR), one of the growth signals that is often over-active in cancer cells, against advanced bronchioloalveolar carcinoma (BAC), a unique subtype of lung cancer that tends to grow within the lungs, sometimes slowly, and not progress elsewhere.
Throughout their development over the past years, the EGFR tyrosine kinase inhibitors Iressa (gefitinib) and Tarceva (erlotinib) have been identified as seeming to be particularly helpful in women compared with men. Only Tarceva is commercially available in the US, but Iressa is widely used in other parts of the world, including Asia, where it continues to be avidly used and studied. Both of these drugs have a consistently higher response rate in women, which has led to some different use patterns in women and men.
Since the earliest clinical trials of EGFR inhibitors in NSCLC, certain clinically defined patient subsets became identified as more likely to show a benefit than others. Such studies suggested that women, patients with adenocarcinomas rather than squamous cell carcinomas, Asian patients, and never-smokers compared with current or former smokers were the patients who would do well with EGFR tyrosine kinase inhibitors like gefitinib (Iressa) or erlotinib (Tarceva).