Image: Courtesy of Mignon Fogarty
 LEARNING ABOUT RESISTANCE: Most cancers engage multiple growth factor, angiogenic, cell cycle, and apoptosis pathways. Frequently, redundant pathways exist, so that as drugs shut one pathway down another pathway takes over. This is one way that cancers become resistant to targeted agents. Early stage tumors tend to secrete a small number of pro-angiogenic factors, whereas late stage tumors secrete a larger number of pro-angiogenic factors.

Targeted anticancer agents have had their ups and downs lately. While Gleevec, Herceptin, and Rituxan are proving useful in a broader array of patients with cancer than initially expected, other targeted agents have disappointed in pivotal clinical trials. In August, AstraZeneca's epidermal growth factor receptor (EGFR) inhibitor, Iressa, failed a Phase III trial in patients with non-small-cell lung cancer (NSCLC). Preclinical studies indicated that Iressa would act synergistically with chemotherapy, but the combination treatment showed no effect on survival benefit....

Interested in reading more?

Magaizne Cover

Become a Member of

Receive full access to digital editions of The Scientist, as well as TS Digest, feature stories, more than 35 years of archives, and much more!
Already a member?