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What: Shares of biopharma company MannKind (Nasdaq: MNKD) shed as much as 45% in intraday trading after the company revealed that the Food and Drug Administration did not approve its inhaled insulin treatment, Afrezza.

So what: This is now the second time that the FDA has declined to approve Afrezza, the first coming back in March of last year. This time around, the agency asked for two additional studies, including one that will compare the company's new inhaler to the previous version. MannKind's CEO, Alfred E. Mann, had been very optimistic about Afrezza and had his money where his mouth was, to the tune of hundreds of millions of dollars.

Now what: An analyst at Robert W. Baird called the FDA's response "the worst case scenario" and slapped a sell rating on the stock, noting that the company's decision to switch to the newer inhaler seemed like a risky move. Looking ahead, it certainly sounds as if the company is still committed to the drug and bringing the FDA a new round of data. Investors will probably want to skip this one, though thanks to the promise of more volatility, speculators may find reason to jump into the fray.

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Fool contributor Matt Koppenheffer does not own shares of any of the companies mentioned. You can check out what Matt is keeping an eye on by visiting his Motley Fool CAPS portfolio, or you can follow Matt on Twitter @KoppTheFool or on his RSS feed. The Fool's disclosure policy prefers dividends over a sharp stick in the eye.