By most measures, it's been a good year for specialty drug developer CV Therapeutics (NASDAQ:CVTX). That year recently got a little better, after CVT announced that it had finally found a European marketing partner for its angina treatment Ranexa.

Ranexa is CVT's top drug, approved for marketing in the U.S. since 2006. In early July, CVT finally also received final marketing approval for Ranexa in the European Union. But it hasn't launched the drug over there yet because of the costs involved, hoping instead to pair up with a larger partner first.

Late last week, CVT finally got its Ranexa partnership deal with the privately held Menarini Group. The deal gives CVT $70 million in up-front cash, as much as $315 million in milestone payments for further commercialization and development, and a "very significant double-digit royalty" rate on all sales of Ranexa by the Menarini Group in Europe and several other locales around the world.

As CVT noted on its conference call, the Menarini Group has one of the largest presences in cardiovascular drug sales in Europe. The 9 million cardiovascular drug sales calls it makes in a year dwarf the 6.5 million made by its nearest competitor, Novartis (NYSE:NVS).

Why does finding a large, well-funded partner like the Menarini Group matter for CVT? Angina is a chronic condition, and as many as 50 million angina prescriptions are written each year in the five largest European countries alone. With several generic drugs on the market making angina a relatively low-margin indication, and a large angina patient population, a drugmaker needs lots of resources just to field a sales force to launch a compound like Ranexa. The Menarini Group already has such a sales force in place, plus experience in selling compounds for several firms, including Pfizer's (NYSE:PFE) Lipitor, GlaxoSmithKline's (NYSE:GSK) asthma medicine Advair, and Merk's (NYSE:MRK) type 2 diabetes drug Januvia.

On the conference call, CVT said that it thought Ranexa could eventually become a "blockbuster" drug in Europe, with sales of at least $1 billion annually. If so, CVT could eventually bring in more than $100 million to $200 million in royalty revenue from the Menarini Group's Ranexa sales. Considering the company had revenue of $117 million over the last four quarters, that's significant.

Ranexa is not expected to launch in Europe until the first quarter of 2009, so we'll have to wait for the actual sales figures to start rolling in. It's never smart to take any drugmaker's potentially pie-in-the-sky sales projections at face value. But if Ranexa can become anything close to a blockbuster drug in Europe, CVT's shares are undervalued at current levels.

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Fool contributor Brian Lawler does not own shares of any company mentioned in this article. Pfizer is both an Inside Value and an Income Investor pick. Glaxo was also chosen by Income Investor. The Fool has an A+ disclosure policy.