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 Medivation (NASDAQ:MDVN), a biopharmaceutical company focused on developing therapies to treat cancer, rallied as much as 15% after the company and its partner, Astellas Pharma, announced positive final results from its phase 3 trial involving Xtandi for chemotherapy-naïve metastatic prostate cancer patients that had progressed on androgen deprivation therapy.

So what: According to Medivation and Astellas' press release after the closing bell yesterday, its PREVAIL study showed that the Xtandi treatment arm had a 29% reduced risk of death compared to the placebo group, and that Xtandi "significantly reduced the risk of radiographic progression or death by 81% compared with placebo treatment." Furthermore, there was a marked delay in the initiation of chemotherapy of 17.2 months (28 months versus 10.8 months) for those taking Xtandi compared to men in the placebo arm, and Xtandi dramatically extended the median time to PSA progression from 2.8 months to 11.2 months. Treatment duration was also notably longer for Xtandi at 16.6 months compared to just 4.6 months for the control arm. On the heels of this data Medivation received price target hikes from Credit Suisse as well as JPMorgan Chase.

Now what: There's absolutely no way to sugarcoat the fact that Xtandi absolutely crushed the placebo in every meaningful way based on these final results, and that it could provide a clear edge over its competitors, including Johnson & Johnson's Zytiga, in terms of advanced prostate cancer treatment. Most Wall Street estimates would have pegged Zytiga as the drug poised to see higher peak sales, but those figures may now need to reverse. I'll personally be happier with Medivation when I see it turning a profit on a regular basis, which should happen this year, but I could also see a scenario where this final data proves strong enough to support its already lofty valuation, as well. If anything, Xtandi now looks like a better than 50-50 shot to expand its usage to a pre-chemo setting, which should greatly expand its top-line growth potential in the coming years.