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 Pharmacyclics (UNKNOWN:PCYC.DL), a biopharmaceutical company developing small molecule drugs to treat cancer and immune mediated diseases, vaulted higher by as much as 21% after the independent data-monitoring committee recommended its late-stage study (known as Resonate) of Imbruvica for relapsed/refractory chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) be stopped early due to statistically significant efficacy.

So what: According to Pharmacyclics' press release, Imbruvica met its primary and secondary endpoints and was demonstrating such efficacy in a study versus GlaxoSmithKline's (NYSE:GSK) Arzerra that the IDMC recommended it be stopped early. Pharmacyclics plans to announce detailed data analysis of its study at an upcoming oncology conference, while both it and development partner Janssen Pharmaceuticals, a subsidiary of Johnson & Johnson (NYSE:JNJ), have informed the Food and Drug Administration, as well as European Medicines Agency, of the IDMC's recommendation.

Now what: To be honest, there was never much of a question that Imbruvica wouldn't meet its primary or secondary endpoints in this late-stage CLL/SLL trial. Today's news, though, demonstrates that Imbruvica's progression-free survival benefit is significantly better than Arzerra's according to the IDMC. It also clears a path for Imbruvica to be potentially be approved by the FDA for CLL, the most common form of leukemia in adults, affecting some 16,000 people annually and currently afflicting more than 100,000 in the U.S. alone. An approval from here on out seems like a formality at this point. The big question now is how well Pharmacyclics and Johnson & Johnson will do when it comes to marketing this potential blockbuster drug.