After weeks of talks, drug industry lobbyists were growing nervous. To cut a deal with the White House on overhauling healthcare, they needed to be sure that President Obama would stop a proposal intended to bring down medicine prices. On June 3, 2009, one of the lobbyists e-mailed Nancy-Ann DeParle, the president's healthcare adviser. Ms. DeParle reassured the lobbyist. Central to Mr. Obama’s drive to remake the nation's healthcare system was an unlikely collaboration with the pharmaceutical industry that forced unappealing trade-offs.