"On July 30, 2013, JNJ secured a new patent for the combination use of Zytiga and prednisone in the treatment of prostate cancer. This extends Zytiga's patent life well into the late 2020s and pretty much erases the threat of generic Zytiga in 2016."
Dec. 2016. And the implication that cheaper Zytiga will replace Xtandi is wrong. By next year, all oncologists will be using Xtandi first. Zytiga will be used when Xtandi stops working. JNJ's best hope - which would take some time and a lot of legal dollars to pull off - would be to create a new drug by combining Zytiga with the Aragon drug.