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 pulmonary medicine researcher InterMune (Nasdaq: ITMN) left investors gasping for air this morning, falling as much as 31.1% overnight on truly epic trading volume.

So what: A new report from IQWiG, which is something like the German equivalent of the FDA, says that the benefits of InterMune's pirfenidone drug aren't worth the gastrointestinal and skin damage it seems to cause. In short, the Germans see "no added value" in this supposed blockbuster drug.

Now what: This German study is more advisory than rulemaking, but what the IQWiG says holds weight with the final drug authorities in Germany. And if this agency finds pirfenidone's side effects too drastic, who's to say that other European bodies and our own FDA won't come to the same conclusion?

Pirfenidone, also known as Esbriet, has indeed traveled a rocky road stateside as well. If InterMune can overcome the skin damage concerns and the lesser gastrointestinal challenge, investors will be swimming in money -- but if not, it's off to penny-stock land. Serious gamblers only, please.

Interested in more info about InterMune? Click here to add it to My Watchlist.

Fool contributor Anders Bylund holds no position in any of the companies mentioned. We Fools may not all hold the same opinion, but we all believe that considering a diverse range of insights makes us better investors. Check out Anders' holdings and bio, or follow him on Twitter and Google+. We have a disclosure policy.