ASCO highlights targeted cancer drugs from Pfizer, Exelixis

A major theme at the big American Society of Clinical Oncology (ASCO) meeting next month will be matching cancer patients with drugs based on the biology of their tumors. The so-called targeted cancer drugs are expected to grab lots of attention because of their ability to home in on specific molecular drivers of tumors while limiting side effects on healthy tissues.

Pfizer's ($PFE) crizotinib is a poster child of the targeted drug theme because of its ability to aid lung cancer patients whose tumors express the ALK gene. Because ALK is a culprit in only about 3 to 5 percent of lung cancer cases, patients' tumors are screened for the gene ahead of treatment. And Exelixis' ($EXEL) targeted drug cabozantinib, or "cabo," targets cancers of the prostate, liver and ovaries that express the MET gene. Really, we're almost to the point at which if you're not doing targeted cancer drug development in some form, you're really not doing cancer drug development.

We've already seen how approved targeted drugs like Roche's Herceptin for breast cancer have changed how the tumors are treated. And over the next several years, it's possible that a bevy of new targeted drugs for complex cancers could reach the market, carrying lots of promise for attacking tumors and hefty price tags that are expected to drive up healthcare costs. Yet the expense will be justified by the life-prolonging benefits that many of these drugs could offer.

"We are shifting from treating cancer based on its location in the body with fairly non-specific treatments to treating cancers based on their molecular and genetic characteristics," said ASCO President George Sledge, as quoted by Reuters.

Another key to targeted drugs is their potential to make clinical development less of a guessing game because patients who participate in trials are screened for the molecular drivers that the treatments are intended to attack. This could remove some of the risk from development.

- check out the Reuters story

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