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 biotechnology company Vanda Pharmaceuticals (VNDA 3.12%) soared a whopping 40% today after the Food and Drug Administration accepted its filing and granted a priority review classification for its non-24-hour sleep disorder drug tasimelteon.

So what: The news suggests that the FDA considers non-24-hour disorder as a serious unmet need and, in turn, raises the probability that tasimelteon will be approved much sooner than expected. According to Vanda, between 65,000 and 95,000 people are affected by Non-24-Hour in the U.S. alone, so Wall Street is naturally excited over the drug's sales potential.

Now what: The FDA plans to complete its review by January 31 and will also discuss the drug with a panel of independent advisors on November 14.

"The agency's acceptance of the NDA and decision to place tasimelteon in a category of expedited review are important milestones for Vanda as we take another step toward our goal of providing patients with a treatment for Non-24," said CEO Mihael Polymeropoulos.

So while the stock might be too hot and risky for average investors, biotech-savvy Fools might want to take a look at Vanda's brightened prospects.