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 Supernus Pharmaceuticals Inc. (NASDAQ:SUPN), a biopharmaceutical company focused on developing therapies to treat central nervous system disorders, surged as much as 27% after announcing the approval of Trokendi XR by the Food and Drug Administration.

So what: Trokendi XR is a once-daily extended-release pill to treat epilepsy and will join the company's other FDA-approved drug, Oxtellar XR, to combat the disease. Trokendi XR can be used on children as young as six years old, with the FDA granting Supernus a waiver on certain pediatric study requirements and a deferral until 2019 on its post-marketing pediatric pharmacokinetic assessment of the drug. Plans are for the company to launch Trokendi XR over the next couple of weeks.

Now what: Based on purely illustrative estimates from Supernus in May of 4% annual market growth in epilepsy prescriptions and 5% price growth, its two drugs could combine to total more than $400 million in revenue five years from now. Of course, that's a utopian scenario and assumes no other drug approvals, but it points to a relatively big opportunity in antiepileptic drugs. However, as I said less than a week ago, even with the company's prognostication of being cash-flow breakeven by the end of next year, I'd rather wait a few quarters and see how Trokendi XR and Oxtellar XR's sales shape up rather than just assume that the launch of Trokendi XR will go smoothly.

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