Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of NPS Pharmaceuticals (UNKNOWN:NPSP.DL), a biopharmaceutical company focused on developing therapies to treat a wide array of diseases and disorders in the U.S., tumbled as much as 16% after the company reported its first-quarter earnings results before the opening bell.

So what: For the quarter, NPS Pharmaceuticals delivered net product sales of $17.9 million compared to just $0.7 million in the year-ago period. This was a 17% sequential increase from the fourth quarter and was powered entirely by Gattex (also known as Revestive in Europe), a drug used to treat short bowel syndrome. Royalty revenue improved slightly to $26.2 million from $24.8 million year over year. Net loss for the quarter shrank modestly to $6.6 million, or $0.06 per share, from $7.8 million or $0.09 in the year-ago quarter. By comparison, Wall Street was expecting a narrower loss of just $0.02 per share.

Where the wheels really fell off the wagon was with NPS' full-year Gattex/Revestive guidance, which was lowered to a new range of $100 million-$110 million from a prior forecast of $110 million-$120 million because of challenges in signing up new patients. NPS partially blamed the weather for its weaker results, but admitted it's still trying to "learn more about SBS market dynamics."

Now what: It's a bit disconcerting when a company has a lead drug with no competition and it admits to not fully understanding how to reach those patients and capitalize on this opportunity. Then again, Gattex's high annual price because of its orphan status and lack of competition do make it an attractive drug for the long term, even if it takes NPS a few quarters to figure out. It also makes NPS Pharmaceuticals a potentially attractive takeover candidate, as I've mentioned previously. Investors will certainly want to adjust their expectations for Gattex in the near term, but I still don't see any reason this drug, combined with NPS' royalty stream, couldn't generate north of $2 in EPS by 2016. Long story short, I'd suggest that biotech-savvy investors with a long-term horizon would be wise to give NPS a closer look, as they may be pleasantly surprised.

Sean Williams has no material interest in any companies mentioned in this article. You can follow him on CAPS under the screen name TMFUltraLong, track every pick he makes under the screen name TrackUltraLong, and check him out on Twitter, where he goes by the handle @TMFUltraLong.

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