Amid underperforming sales and an expensive outcomes trial tab, Takeda is walking away from its marketing pact with Orexigen ($OREX) for obesity therapy Contrave. Now, it'll be up to Orexigen to compete in the U.S. without the Japanese pharma's 900 reps, who helped it grab a leading slice of the pie despite third-to-market entry. But in the meantime, Orexigen is also on the hook for a cardiovascular outcomes trial that could cost up to $250 million--a tall order for the California drugmaker, which netted just $53 million in Contrave sales last year. More from FiercePharmaMarketing