Among the 5,000 studies being discussed by 30,000 oncologists at this weekend’s meeting of American Society of Clinical Oncology, listen for the buzz over a single gene.

     It’s called KRAS, and a growing body of evidence suggests that cancers with the standard form of this gene respond better to an important class of cancer drugs than tumors with a common mutation of the gene. The class of cancer drugs, known as EGFR inhibitors, includes Imclone’s Erbitux and Amgen’s Vectibix, as well as several experimental drugs.

     Data from one of the most eagerly awaited studies of the weekend will show how colorectal cancer patients with the KRAS mutation respond to Erbitux, compared to those whose cancer has the standard form of the gene. While those data haven’t been published yet, data from plenty of other KRAS studies on this weekend’s agenda were posted online a few weeks ago — including this one, which suggested Erbitux works better in patients who had the normal form of the gene.

     Indeed, searching the ASCO abstracts for KRAS turns up nearly 300 results. (You can sort through them yourself here.

     While studies of KRAS are continuing, the industry is already betting that the connection will hold up. In a recent phone interview, Pfizer’s Charles Baum, in oncology R&D, told the Health Blog that the company is testing an experimental drug that blocks EGFR (as well as a few other receptors) in patients who have the standard form of the gene.

     And as Dow Jones Newswires notes, drug makers including AstraZeneca are also rummaging through the drawers looking for molecules that may work in patients who do have the KRAS mutation — and who may need alternatives to EGFR inhibitors.

Update: Just today, European regulators recommended that Erbitux be approved as first-line therapy for advanced colorectal cancer — but only in patients who have the standard form of the KRAS gene (sometimes referred to as “wild type”). Here’s the announcement from Merck KGaA, which markets Erbitux in Europe.

DNA image via Wikimedia Commons