The balm of Gilead no longer comes cheap.

Charging up to $1,000 a pill in the U.S., the antiviral biotech leader Gilead Sciences Inc. rung up a record $10 billion in the first year of marketing its hepatitis wonder drug Sovaldi. The scale of the market is astonishing, because hepatitis C infects about 150 million people worldwide. Sovaldi could theoretically save roughly 90 percent of the 700,000 among them who die each year from liver disease or liver cancer. But few hepatitis patients can pay full freight. Gilead has made generic versions available in the world’s poorest precincts. But hepatitis is also endemic in middle-income countries. By assaulting Sovaldi’s patents in those nations, law-savvy health advocates have become the bane of Gilead.