Advances in targeted therapy stand out at ASCO

At the recent annual meeting of the American Society of Clinical Oncology (ASCO), some 25,000 cancer specialists from around the world came to Orlando, Fla., to consider the latest advances in cancer care, treatment, and prevention. Novel targeted therapies for major cancers abounded, as did improvements in quality of life for patients suffering adverse effects from conventional therapy. Here are some highlights:

About 800,000 U.S. cancer patients will likely develop anemia due to chemotherapy this year, according to the American Cancer Society. This may help explain the "buzz" around a poster showing how the anemia drug darbepoetin alfa (Aranesp, Amgen), dosed only once every three weeks, corrected the condition.

This new dosing schedule "could greatly simplify anemia treatment and also be coordinated with standard chemotherapy regimens," said lead investigator Ralph Boccia, M.D., Georgetown University Medical Center. "Chemotherapy is usually given every three weeks. Our results suggest that with an every-three-week dosing of 300 mcg of Aranesp, physicians may effectively combine anemia treatment and chemotherapy on the same schedule."

Based on these positive data, Amgen has applied to the Food & Drug Administration for a supplemental biologics license for every-three-week dosing of Aranesp.

Other treatment and prevention strategies, highlighted at ASCO, include the following:

In the multinational CONFIRM-1 trial, 1,168 patients were randomly assigned to receive FOLFOX (oxaliplatin, 5-fluorouracil [5-FU], and leucovorin) conventional first-line therapy for metastatic colorectal cancer with either the investigational agent PTK/ZK (Novartis/Schering AG) or placebo. PTK/ZK is a novel oral small molecule that blocks angiogenesis by inhibiting tyrosine kinase signaling from all VEGF (vascular endothelial growth factor) receptors, explained Hecht. "It differs from the anti-VEGF agent bevacizumab [Avastin, Genentech] by blocking the receptors directly instead of via a protein that binds to the receptors." But adding bevacizumab to first- or second-line treatment extended survival in some studies, he noted.

Results of the trial showed that PTK/ZK plus FOLFOX improved progression-free survival by an insignificant 12%. Yet strangely, patients with high blood levels of the enzyme lactic dehydrogenase (LDH) had a significant survival benefit of 39%. High levels of LDH are generally indicative of poor outcomes.

"The fact that some groups of patients showed a significant benefit suggests there are better ways of using these types of drugs," Hecht concluded. Final survival results from the ongoing PTK/ZK study will be presented at ASCO next year. Novartis and Schering announced jointly that they expect to file for FDA approval of PTK/ZK in 2007.