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What: Shares of biopharma company Regeneron Pharmaceuticals (Nasdaq: REGN) spiked today, rising as much as 38% on huge volume.

So what: Positive study data is pretty much always music to the ears of biopharma investors. In Regeneron's case, the company -- along with partner sanofi-aventis (NYSE: SNY) -- announced positive results from its phase III study of Zaltrap, a treatment for metastatic colorectal cancer. When used in combination with chemotherapy, Zaltrap was able to improve overall survival for patients versus a placebo.

Now what: Commenting on the results, Regeneron's chief scientific officer said that Regeneron and sanofi-aventis will now submit applications for marketing approval for Zaltrap to the U.S. Food and Drug Administration and the European Medicines Agency in the second half of the year. Investors in sanofi-aventis hardly blinked at the news, as the market for Zaltrap is relatively modest. However, for a smaller company like Regeneron, the impact of an approval (which is still far from guaranteed) would be more significant.

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