The Food and Drug Administration, which has yet to approve an EGFR inhibitor, is widely expected to give the nod to AstraZeneca's Iressa (ZD1839) by this summer, an event that could herald a new era in cancer medication. Two-thirds of solid tumors arise from epithelial tissues, and studies suggest that EGFR inhibitors can stabilize or shrink many of these malignancies. The new drugs' hit list could eventually include cancers of the lung, pancreas, head and neck, breast, prostate, colon, stomach, ovaries, and brain.
Genentech's Herceptin and Novartis' Gleevec, in contrast, target only one or two cancers apiece. These receptor and tyrosine kinase inhibitors, FDA-approved in 1998 and 2001, respectively, were celebrated as the first "smart bombs" against tumors.
Versatility is not the EGFR inhibitors' only potential trump card. So far, side effects appear mild (in Iressa's case, they are limited to skin rashes and diarrhea). Some inhibitors are available as ...
