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 MannKind (NASDAQ:MNKD), a clinical-stage biopharmaceutical company focused on developing therapies to treat diabetes and cancer, tumbled as much as 20% after updating shareholders on the status of its marketing application for inhaled diabetes therapy Afrezza before the opening bell.

So what: According to MannKind's press release, the Food and Drug Administration had extended its PDUFA decision on approving or rejecting MannKind's potential blockbuster therapy by three months until July 15, 2014. The move was made by the FDA to have more length of time to review the data submitted in order to make a proper approval or rejection decision. MannKind's original PDUFA date had been scheduled for one week from tomorrow. As a refresher, last week the FDA panel recommended Afrezza be approved by vote of 13-1 in type 1 diabetes and 14-0 in type 2 diabetes as a means for patients to establish glycemic control.

Now what: That rumble under your feet isn't an earthquake; it's actually the collective groaning and moaning or options investors who had been angling for a decision by April 15 that now have to rearrange those plans. This is certainly a disappointment from the aspect that MannKind is burning through an incredible amount of cash each month and now must push back a potential commercialization by another three months. Over the long term, though, if approved in at least the most common type of diabetes, type 2, and launched successfully, this three-month delay could be a distant memory. As for me, the concerns such as whether or not Afrezza will get the nod of approval in type 1 diabetes, the PDUFA decision delay, and its lack of a commercialization partner, give me enough pause to simply stick to the sidelines for the time being.

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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