President Trump’s aims to cut American healthcare costs face a hurdle from trade policy, with duties proposed on Chinese exports of pharmaceuticals as a result of the section 301 review. Chinese suppliers, led by Zhejiang Pharma, have had little success in the U.S., with shipments of just $405 million in the past 12 months or 0.5% of the total. Shipments actually fell 13% in the first quarter on a year earlier, suggesting section 301 tariffs had not been expected. Zhejiang’s exports to the U.S. surged 42% higher in April, likely as it sought to preempt duties that would have to be paid b...