Big trouble seen for targeted cancer drugs

Researchers have discovered that the genetic complexities of cancer could thwart current methods of matching a patient's tumor with targeted drugs. The study by U.K. researchers could mean that more extensive digging into the genetics of cancer will be required before dispatching targeted treatments to attack tumors, a change that could drive up the already high cost of cancer care.

With an arsenal of targeted cancer drugs at their disposal now, doctors use DNA tests, typically of a single tumor specimen from their patients, to determine which meds are the best fit to take out their tumors. Alas, U.K. researchers conducted DNA tests from multiple areas of kidney tumors and found that only one third of all the key genetic mutations were present in all tumor samples, The Wall Street Journal reported.

The study is unlikely to unhinge enthusiasm about targeted cancer meds, but the findings could prompt doctors to take extra caution before using the drugs. What's more, the results could explain how cancers eventually bounce back after gene-targeted drug treatments, Bloomberg reported. And, rather than forming to overcome the effects of targeted drugs, the mutations that drive a cancer's comeback could already be present before treatment with the meds.

The targeted cancer drug phenomenon has pushed many of the top drugmakers into action, with Pfizer ($PFE), Roche ($RHBBY), and Novartis ($NVS) among the leading developers of such meds. It's probably too early to tell how the results of the U.K. study impact those companies' fortunes, but it's worth watching how the study impacts enthusiasm in the field.

"It's a sobering finding," Andrew Futreal, a co-author of the study and former director of cancer genetics and genomics at Wellcome Trust Sanger Institute in London, said, as quoted by the WSJ. He added that, with just one biopsy, "you might miss the connection between the mutation and whatever outcome you are looking at."

- read Bloomberg's article
- check out the WSJ piece