Product development glitches continue to depress share prices at AstraZeneca. Poor trial results for the company's cancer
drug Iressa followed hard on the heels of bad news about its cholesterol treatment Crestor (rosuvastatin).
For Crestor, the negative side effects of muscle weakness and kidney damage emerged after trial doses of 80 milligrams-the
highest dose under investigation. Although the company says it is only seeking approval of the lower doses of 10, 20, and
40 milligrams in United States and Europe, that information failed to allay regulators' concerns, especially in the light
of Bayer's problems with the statin Baycol (cerivastatin), which was pulled from the market. However, admitting that approval
for Crestor is likely to be delayed by at least another nine months while it awaits further trial results, AZ remains optimistic
about the drug's potential. A company spokesman stated,"We are still confident it will be a big product for us."
Iressa, being tested both as a monotherapy and in combination with platinum-based medicines, is the first in class of a new
type of drug called an epithelial growth factor inhibitor. It is already approved in Japan as monotherapy for non-small-cell
lung cancer. AZ had pinned its hopes on the product's sales as a combination therapy, but trials showed that it perfomed no
better than platinum therapy alone.
Although AZ is still pursuing approval for Iressa as monotherapy, and Phase II trials in head and neck, colorectal, and breast
cancers are underway, the failure of the combination trials will clearly affect its sales potential. After the announcement,
AZ shares plummeted by 12 percent.
Several other drugs in the same category are also under development, notably Erbitux (cetuximab) from Bristol-Myers Squibb
and ImClone, for which FDA has already requested further trials. Genentech and OSI are developing another, but so far the
results have been disappointing. Shares in both those companies also slipped after the Iressa announcement.