Drug developer Aspreva Pharmaceuticals (NASDAQ:ASPV) released its quarterly results yesterday, but investors already know what its revenues numbers will be weeks in advance because the company pre-announces its royalty revenues from the one marketed drug it receives royalties on -- the immunosuppressant CellCept.

For the third quarter, revenues came in at $48 million (nearly three times the level of 2005), and net income was $25 million, giving Aspreva an eye-popping 53% net margin. Earnings per share were $0.71, compared to the $0.09 a share the company earned last year.

Guidance for revenues from CellCept was made more visible from the previously announced "in excess of $200 million" for 2006 to the more narrow range of $210 million-$215 million for the year. If CellCept can hit this guidance, then that would bring revenues up a minimum of 175%, compared to the $76.5 million the company received in 2005.

Of course, there's a catch to these revenues: They'll start to be negatively affected by patent expirations and the presumed entrance of generic competition as early as 2009.

Even with upcoming patent losses, Aspreva is testing CellCept in additional indications in order to increase its sales beforehand. Currently, CellCept is in phase 3 testing for three autoimmune diseases. The great thing about testing an already-approved drug like CellCept for new indications is that off-label sales in these diseases will pick up even before the drug gets approved to treat the new disease.

The lupus trial completed enrollment a month ago, and the trial should be finished by early 2007, with results announced shortly thereafter. Trial results in patients with pemphigus vulgaris have been pushed back to the second quarter of 2008 in order to enroll more patients with this very rare disease, but the lupus results are by far more important to the future sales growth of CellCept.

With such a rapid uptake in sales, operating cash flows came in at $35 million for the quarter, bringing CellCept's cash and equivalents to $228 million. With the aforementioned two clinical trials for CellCept being the company's only active clinical trials, it will be very interesting to see how Aspreva spends this cash. Whether Aspreva wisely invests in licensing new drugs from other companies or returning some of the cash to shareholders will ultimately determine its future and how well an investment in shares of Aspreva will fare.

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Fool contributor Brian Lawler does not own shares of any company mentioned in this article. The Fool has a disclosure policy.