Yesterday, biopharmaceutical firm QLT (NASDAQ:QLTI) announced first-quarter sales numbers for its top drug, the macular degeneration treatment Visudyne. Sales of the drug were down 43% this quarter to $61 million versus the same period last year as a result of increased competition from Genentech (NYSE:DNA).  

When I last wrote about QLT two months ago, I said "There is some value in shares of QLT" and that "really patient investors might get an opportunity to catch some shares of cash-rich QLT on the cheap sometime this year." Since then, shares have fallen nearly 20% and QLT is trading at an enterprise value of roughly $500 million. This may seem cheap considering that its other marketed drug, the hormone therapy drug Eligard, is expected to grow sales at least 16% in 2007, and that QLT had $0.37 a share in non-GAAP earnings last year.

In the sales numbers press release, QLT's management stated that U.S. sales of Visudyne have finally stabilized. Even though sales of the drug may have finally stabilized domestically at $8 million this quarter, the $53 million worth of international sales of Visudyne have yet to feel the deleterious effects of oncoming major competition from the likes of Genentech's Lucentis. Even worse, QLT's Visudyne European Union marketing partner, Novartis (NYSE:NVS), will also be marketing Lucentis as well -- so Visudyne won't even have the relative advantage of a superior sales force detailing the drug. In other words, it is possible that Visudyne will follow the same path in the EU as it has in the U.S.: the complete hollowing out of the compound's sales.

With Visudyne probably contributing very little to its bottom line in the future, any investment in shares of QLT today is mostly a bet on the success of Eligard. Shares are cheaper today, and as I've said before, there is some value with the company -- it's just not at a $500 million enterprise value. Value investors may get shares on an even bigger sale later in the year or in 2008 once the shoe drops on Visudyne's European sales.

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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.