U.S. sales of Xtandi (enzalutamide) jumped 74 percent in the second quarter over the same period a year earlier, to $143.7 million, Medivation Inc. reported after Thursday's market close, and the company's second quarter revenue from its collaboration with partner Astellas Pharma Inc. soared 111 percent over the same period in 2013, to $148.1 million.