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 Insys Therapeutics (NASDAQ:INSY), a biopharmaceutical company focused on developing therapies for cancer-supportive care, rocketed higher by as much as 27% after reporting much better-than-expected fourth-quarter results.

So what: For the quarter, Insys delivered $40.2 million in revenue, a 673% increase over the year-ago quarter, as Subsys, the company's FDA-approved treatment for breakthrough cancer pain, saw its revenue climb to $39.2 million. This alone was a 38% increase over the sequential third quarter. Adjusted profit rose to $0.71 per share relative to a $0.59-per-share loss in the corresponding quarter in 2012. By comparison, Wall Street had expected just $34.7 million in revenue and $0.55 in EPS, so Insys absolutely crushed estimates. The company's press release also notes that it plans to file for at least one new drug application and four investigational new drug applications in 2014.

Now what: At the moment, the correlation is pretty clear: Insys' success is wholly dependent on the rapid growth and acceptance of its cancer pain med Subsys. It's difficult to ignore 38% quarterly sequential growth, but with Insys' share price up more than 650% from its 52-week low, it could also give investors reason for pause as well. I would suggest, even at 44 times forward earnings, that Insys could still have further upside given its gross margin, which is nearing 90%, its growing pipeline, and the fact that the Street appears to have underestimated Subsys' peak potential. I wouldn't go so far as to suggest it has another 650% run up its sleeve, but I could see shares moving modestly higher over the next couple of years on Subsys' growth as well as the advancement of key pipeline therapies.

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