Gilead Sciences, a California biopharmaceutical company, scored a major breakthrough in 2013 when the Food and Drug Administration approved Sovaldi, a pill that could cure hepatitis C when combined with another antiviral medication. And then Gilead delivered another breakthrough, albeit not a good one: It priced Sovaldi at $1,000 per pill, or $84,000 to $168,000 per course of treatment. The pricing stunned patients, insurers and state governments, which were suddenly exposed to billions of dollars in potential prescription costs.