Oh, Onyx Pharmaceuticals (NASDAQ:ONXX), how I want to love thee. You've got a miracle drug in cancer treatment Nexavar, but your lack of a pipeline just isn't my thing.

That was my feeling up until yesterday. It's started to fix the problem of being pipeline-less. Yesterday, Onyx licensed a pre-clinical drug from England's BTG International -- but it's got a new problem to worry about. Nexavar's growth seems to be coming to a screeching halt.

 

Q1 2008

Q2 2008

Q3 2008

Q4 2008 guidance**

Nexavar Sales*

$151.9

$168.5

$180.9

$158.7-$173.7

Quarter-Over-Quarter Increase

21.6%

10.9%

7.4%

(12.3%)-(4.0%)

Source: Company press releases. *In millions. **Based on full-year guidance of $660 million to $675 million.

Guiding for a quarter-over-quarter drop in sales seems a little ridiculous even for a management that has been pretty conservative in guidance; just last quarter it was still guiding to possibly break even for the year, which -- excluding the milestone payment to BTG -- seems a near certainty at this point.

It seems more likely that sales will come in flat quarter over quarter as the stronger dollar cuts down international growth a little, the company fights for kidney cancer patients with Wyeth's (NYSE:WYE) Torisel and Pfizer's (NYSE:PFE) Sutent, and the liver cancer market gets saturated.

The success of Onyx over the next few years is going to come down to whether it can get Nexavar approved to treat even more cancers and be used as an adjunct to surgery for liver and kidney cancer. Both possibilities could turn the drug into a substantial blockbuster, but approvals are still a ways off as the clinical trials are still underway.

Much like investors in Dendreon (NASDAQ:DNDN), Onyx's investors are sitting around waiting for a catalyst to bring it back to the highs experienced last year.

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Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. Pfizer is a selection of the Income Investor and Inside Value newsletters. The Fool owns shares of Pfizer. The Fool has a disclosure policy.