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 Aratana Therapeutics (NASDAQ:PETX), a clinical-stage biopharmaceutical company engaged in developing therapies to treat pets, jumped as much as 11% after providing a year-end development update on its pipeline.

So what: According to the press release, Aratana met all of its 2013 milestone developments which are sure to make investors happy. In its clinical study of AT-001 for dogs with osteoarthritis, Aratana today announced broader data which includes a clinical success rate of 61.6% in the AT-001 arm as compared to 42.2% for the placebo group. For AT-002, its inappetence drug, Aratana notes that it's begun initiating its effectiveness study which will enroll approximately 150 client-owned dogs in January with top-line results expected in the first-half of 2015. Finally, Aratana announced plans to begin a field study on AT-003 for the management of post-operative pain in dogs.

Now what: Aratana is a very troublesome stock to put a valuation on because it's entirely in the clinical stages of its development, yet Wall Street pegs the company to be worth north of $425 million which seems pretty steep. On the other hand, pet owners will do anything necessary to ensure the health of their pets, and that means paying hefty prices for branded medications. I could certainly see Aratana having a very bright future, but would for the time being stick to the sidelines until it has at least one drug approved for marketing.

Fool contributor 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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