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What: Shares of Seattle Genetics (NASDAQ:SGEN) are trading more than 12% higher today after the biotech company announced a better-than-expected quarter and updated investors on the state of two pipeline drugs and on the global rollout of ADCETRIS, its treatment for Hodgkin and anaplastic large cell lymphoma.

So what: Seattle Genetics reported fourth-quarter revenue of $67.4 million, a 5.5% year-over-year improvement and well ahead of Wall Street's $59.3 million consensus thanks to $38.5 million in ADCETRIS sales for the quarter. The company's full-year revenue of $269.3 million represented a 27.8 % improvement on 2012's result and was boosted by $144.7 million in ADCETRIS revenue. However, Seattle Genetics reported a quarterly net loss of $0.13 per share, which was a good thing in investors' eyes, as Wall Street had anticipated a much steeper $0.24 loss per share.

ADCETRIS is now approved in 39 countries and should produce further data from several trials, most notably from a phase 3 AETHERA study, which should be completed by the second half of 2014. Seattle Genetics also expects to produce new data on two of the four new antibody-drug conjugates (ADCs) now in clinical trials, SGN-CD19A and SGN-CD33A, at some point this year.

Now what: Seattle Genetics has only projected net revenues of $155 million to $165 million from ADCETRIS, and added another $55 million to $65 million in licensing revenue to the tally for a combined revenue guidance range of $210 million to $230 million. That's lower than 2013's revenue numbers, but at this point, Seattle Genetics investors are bound to focus more on some of the ADCs moving through the trial process. Investing based on the outcome of a trial that will wrap at some point in the future is always a gamble, even if you think you know everything you can know about the drug being tested. At the very least, make sure you have a firm understanding of Seattle Genetics' pipeline before plunging in.

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Alex Planes has no position in any stocks mentioned. The Motley Fool recommends Seattle Genetics. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.