Zytiga, a pill for prostate cancer that J&J acquired before it was approved, that is competing with Xtandi, a competing pill from Medivation. Duato said that two-thirds of Xtandi use has been in patients who already took Zytiga, and that a recent poll of doctors predicted Zytiga would remain the top seller in 2016.
Xarelto, a new blood thinner to replace warfarin in preventing strokes among patients with atrial fibrillation, a heart rhythm disorder. It is competing with Pradaxa, from Boehringer Ingelheim, and Eliquis, from Pfizer and Bristol-Myers Squibb.
If you - or the Forbes reporter you quote - really understood the market for prostate cancer drugs, you could hardly say that Zytiga is "creaming" Xtandi. Using J&J's own figures, in the chemo-refractory segment, Zytiga's market share has fallen from 70% to under 60%, while Xtandi, which was not even marketed for a portion of this period, went from 0% to 30%. Much of Xtandi's gain came at the expense of Jevtana, which fell from 20% to under 10% share of market.
To say that "two-thirds of Xtandi use has been in patients who already took Zytiga" should not be reassuring to J&J, since Zytiga has been on the market much longer and patients who are using Zytiga are only switched to Xtandi when Zytiga stops working for them. The fact that 1/3 of Xtandi usage is among patients who have never been on Zytiga demonstrates that oncologists are increasingly starting patients on Xtandi rather than Zytiga.
The "recent poll of doctors" does not say whether the respondents were oncologists or urologists. Oncologists have a much wider awareness of Xtandi and are a much more important target audience. Most importantly, however, Zytiga was never able to shoe a benefit in OS. (or at least they didn't let the study run long enough to do so) If MDVN's PREVAIL study, which will be reported this year, is able to demonstrate an OS benefit, Zytiga will truly be getting "creamed".