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 Ariad Pharmaceuticals, (NASDAQ:ARIA), a biopharmaceutical company focused on developing cancer therapies, plunged as much as 43% -- its third plunge of 42% or more in October -- after announcing that the Food and Drug Administration requested it temporarily suspend sales of its blood cancer drug Iclusig.

So what: According to Ariad's press release, the FDA informed Ariad of its request to temporarily suspend sales of Iclusig -- a treatment for resistant or intolerant chronic myeloid leukemia and Philadelphia chromosome-positive acute lymphoblastic leukemia -- yesterday, and that it plans to work with the FDA to potentially relabel Iclusig to get it back on the market. This temporary sales suspension relates to Ariad's findings, announced three weeks ago, that 11.8% of patients on Iclusig experienced blood clots in their arteries in a two-year follow-up study compared to just 8% at the 11-month mark.

Now what: To be honest, the only shocking aspect I see is how the share price isn't down even more! Although the suspension is only labeled as "temporary" in Ariad's press release, and Iclusig could very well make it back to market, I struggle to see how Iclusig's potential toxicity is going to make it a marketable pipeline option. With seven of its eight clinical trials still involving Iclusig, Ariad would almost need to start from scratch. Plus, even if Iclusig makes it back to pharmacy shelves what doctor is going to prescribe, or patient be willing to take, Iclusig following Ariad's two-year follow-up study? There are a lot of unanswered questions here. Thankfully, Ariad still has nearly $342 million in cash on hand, so we'll be around to get those answers... eventually.