Last week, the US Food and Drug Administration issued an announcement with a title that only a federal bureaucrat could write: “FDA approves Kalydeco to treat rare form of cystic fibrosis.’’ In fact, it was a blockbuster development, the first drug that would treat the cause, rather than the symptoms, of CF, a medication that showed such breathtaking results in clinical trials that it was sanctioned by the FDA in about half the typical time. And behind that announcement sits a human narrative, a quarter century in the making, of loss, hope, and triumph.