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 Avanir Pharmaceuticals (UNKNOWN:AVNR.DL), a biopharmaceutical company focused on developing therapies to treat central nervous system disorders, skyrocketed by as much as 69% after the company reporting positive midstage results for AVP-923 as a treatment for agitation associated with Alzheimer's disease.

So what: According to the company's early morning press release, AVP-923 met its primary endpoint of significantly reducing agitation in Alzheimer's patients relative to the placebo based on the agitation/aggression domain score of the neuropsychiatric inventory, or NPI. The trials' secondary endpoints also pointed toward AVP-923's efficacy, including the total NPI score, clinical global impression of change-agitation, patient global impression of change, and various measures of caregiver burden. Avanir notes that the drug was generally well-tolerated with only a small percentage of patients dropping out of the trial due to adverse events.

Now what: At first it might be a bit perplexing to understand why Avanir shares shot up so quickly considering that this drug is aimed at treating just a symptom of Alzheimer's disease and not the disease itself. However, at the moment there are no drugs approved by the Food and Drug Administration to treat agitation associated with Alzheimer's disease, which can be one of the disease's more unpleasant side effects for the patient, family, and/or caregiver.

Furthermore, Alzheimer's disease is among the toughest-to-treat diseases, meaning an approved therapy to abate symptoms of the disease could have a very long shelf life for the innovating company. As for me, I'm not thrilled at the idea of chasing Avanir higher following today's move given its ongoing losses, but I'd certainly suggest adding the company to your watchlist for future reference in case it suffers a sizable retracement.

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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