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AstraZeneca Races Imclone to Approval for Cancer Drugs

Iressa may provide some competition for Imclone's highly touted C225.

AstraZeneca (AZN) - Get Astrazeneca PLC Sponsored ADR Report appears to have a promising cancer drug on its hands, which could present a challenge to a rival product from Imclone Systems (IMCL) .

The British pharmaceutical firm will present detailed results for its new cancer drug, Iressa, at a medical conference beginning Oct. 29 in Miami Beach, Fla. But on Friday, research abstracts for the drug were made public, impressing some drug analysts with stronger-than-expected efficacy results.

Results of the Results

If Iressa's early results hold up to scrutiny and are confirmed by later trials, the drug could be submitted to the Food and Drug Administration for approval by the end of the year, with a decision coming in the second half of 2002.

That would put it just steps behind IMC-C225, the highly anticipated drug from Imclone, which recently partnered with

Bristol-Myers Squibb

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. The companies should complete the C225 FDA filing next month and hear back on a decision in the first half of next year.

Both Iressa and C225 belong to a new class of experimental drugs that work by blocking a protein called the epidermal growth factor receptor present in large quantities in many cancer cells. When the protein is blocked, cancer cells seem to stop growing or shrink, leaving healthy cells intact. It's important to remember that these drugs do not cure cancer; they only slow the disease. But that's still a big deal in cancer, so if these drugs end up working, sales could reach well into the billions of dollars.

Imclone already has publicized strong test results for C225, leading many investors to focus their attention on the company. AstraZeneca, by contrast, has kept a fairly low profile with Iressa. Friday's abstract release was the first definitive news on the drug since the spring.

The results: Iressa racked up an 18.7% response rate in patients suffering from advanced stages of non-small cell lung cancer, according to the research abstract. These patients were given Iressa in pill form after failing to respond to existing chemotherapy drugs.

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More detailed results will be made public at the upcoming cancer research meeting organized by the American Association for Cancer Research and the European Organization for the Research and Treatment of Cancer.

"The Iressa results are impressive, and I think it really underscores the fact that the horse race between Iressa and C225 is a lot closer than most people think," says Sanford Bernstein drug analyst Catherine Arnold.

Imclone has predicted that C225 will reach peak annual sales of about $1.5 billion if it gets approved. But Arnold believes that Iressa, if it also makes it to market, "could steal away some of that revenue." She is forecasting Iressa peak sales of about $800 million a year. (She rates AstraZeneca and Bristol-Myers market perform, but she sees the Iressa abstract release as positive for the former and mildly negative for the latter. Her firm doesn't do underwriting.)

Apples to Oranges

There are some important differences between Iressa and C225 that make direct comparisons difficult. Iressa is a small-molecule drug that works inside of cancer cells; C225 is a monoclonal antibody that interacts with proteins on the outside of cells. Biotech observers are split over which approach will work better, and the drugs haven't been tested enough to provide definitive proof either way.

Iressa also is being tested as a single-agent therapy against various forms of cancer, as well as in combination with existing chemotherapy drugs. AstraZeneca hopes to get Iressa approved first to treat non-small cell lung cancer, but it's also investigating uses in colorectal, head and neck and prostate cancers. Friday's abstract summarized a test of Iressa as a single-agent therapy conducted in Europe and Japan.

C225, on the other hand, is being developed only as a combination therapy with existing chemotherapy drugs. The drug's first approved use will be in colorectal cancer patients, although Imclone is also hoping to expand its use into the same cancers as those being looked at for Iressa.

One hedge fund manager, who is long Imclone and has no position in AstraZeneca, doesn't believe investors should read much into the competition between the two drugs.

"The Iressa results look strong, but that doesn't take away from C225," he says. "If anything, it just makes the whole class of drugs look better."

And a clinical oncologist who has kept close tabs on these drugs, but doesn't own the stocks, says he's more comfortable with C225 and its chances for approval at this point. The Iressa results look good, he says, but he's waiting for more results to be released that would further validate the drug's efficacy.

Specifically, AstraZeneca has tested Iressa in U.S. lung cancer patients, but has not yet made the results public. But that hasn't stopped a rumor from spreading among oncologists and Wall Street insiders of less-than-fantastic, single-digit efficacy results. Of course, the much stronger international results released Friday suggest a chink that in rumor's armor.

Cancer is big business, so companies like Imclone and AstraZeneca have a lot riding on the outcomes of their drugs. That means investors can expect to hear a lot of speculative talk and spin control over the next six months or so. Ultimately, it will be up to the FDA to make a decision on the approvability of these drugs.