Is something amiss at

Imclone Systems

(IMCL)

?

Wall Street biotech mavens have been buzzing about Imclone for the last several days, enough to send shares of the company lower.

The issue is the status of Imclone's highly anticipated and well-publicized experimental cancer drug, Erbitux, known previously as IMC-C225. Imclone filed an approval application for Erbitux with the

Food and Drug Administration

at the very end of October. But now, fears are rising that the FDA's acceptance of that application, expected by Dec. 31, could be delayed.

At this point, however, fears of an Erbitux delay seem to be based more on educated guesswork than on real facts. Still, Imclone shares fell 6% Monday and Tuesday and are off another $3.64, or 5.5%, to $62.11 in recent Wednesday trading.

It takes a good understanding of the somewhat arcane realm of FDA regulations to get a handle on this issue. The Erbitux approval application is being handled by the FDA's Center for Biologic Evaluation and Research. Under its own rules, CBER usually makes an internal decision to accept or reject a drug application within 45 days of submission. For Imclone, that was Dec. 15. But if CBER has concerns or questions about the drug application, it can take another 15 days to respond to the sponsoring drug company.

At this point, Imclone is in that 15-day window, which will close Dec. 31. Does this indicate a problem? The answer is still unclear and seems to depend on how bullish, or bearish, you are on Imclone and Erbitux.

Supporters contend that, at worst, the FDA might be asking for a bit more information from Imclone for its Erbitux application -- not an uncommon occurrence at all. That information will be provided promptly and the FDA will accept the application in time, they say. No problem.

But Imclone skeptics are speculating that the FDA is asking for information that might be too difficult to pull together in time. This could force a short delay.

Imclone executives would not return phone calls seeking comment.

Arguing over the possibility of a short delay in the acceptance of a drug application -- and not whether the drug will be ultimately approved -- seems to be just a bunch of meaningless biotech navel-gazing. But for Imclone, it is important, at least in the short term.

Under its $2 billion investment/co-marketing deal with

Bristol-Myers Squibb

(BMY) - Get Report

, Imclone gets paid $300 million when the FDA accepts the Erbitux filing. Also, Imclone executives have been very public with their belief that the FDA will review Erbitux with alacrity. This would include acceptance of the Erbitux filing by Dec. 31 and getting an important slot for the drug on the agenda of the Feb.27-28 meeting of the FDA's Oncologic Drug Advisory Committee. Once the advisory panel green-lights Erbitux, the full FDA can approve the drug in the first half of next year, as expected.

But if the Erbitux filing is delayed, the possibility is raised that the drug doesn't get scheduled for the February advisory panel meeting. That would push Eribitux to the next scheduled meeting in June, a significant delay that could force Imclone and Wall Street analysts to reduce near-term revenue estimates.

It would also put a short-term dent in Imclone's stock price, because investor expectations of a speedy approval are already baked into the company's hefty $4.5 billion market value.

In a research note published in mid-November, Morgan Stanley biotech analyst Doug Lind predicted that Erbitux would be approved by the FDA in April, and he was forecasting $167 million in revenue for the drug in 2002. But if Erbitux is not approved until much later in the year, that revenue estimate will have to be taken down. (Lind rates Imclone outperform, and his firm has done banking for the company.)

Unfortunately, all this is just speculation, because no one really seems to know what's going on between Imclone and the FDA. Imclone has not made any public statements on the matter. Calls made Tuesday to five hedge funds by

TheStreet.com

yielded a lot of speculation and guesswork but no hard facts.

Late Tuesday, CIBC World Markets biotech analyst Matt Geller published a research note stating that concerns about an Erbitux delay were unfounded and that the FDA is not required to say anything to Imclone until the very end of December. Geller believes the drug's filing is on schedule and will meet all expectations. He rates Imclone strong buy, and his firm hasn't done banking for the company.

Anxious Imclone investors are just going to have to ride out the storm and wait for something definitive from the company. The deadline for such an answer is only 12 days away.