"For a real-world example, they pointed to Gilead Sciences, which markets treatments for hepatitis C that have cure rates exceeding 90 percent. In 2015, the company’s hepatitis C treatment sales peaked at $12.5 billion. But as more people were cured and there were fewer infected individuals to spread the disease, sales began to languish. Goldman Sachs analysts estimate that the treatments will bring in less than $4 billion this year. 
“[Gilead]’s rapid rise and fall of its hepatitis C franchise highlights one of the dynamics of an effective drug that permanently cures a disease, resulting in a gradual exhaustion of the prevalent pool of patients,” the analysts wrote. The report noted that diseases such as common cancers—where the “incident pool remains stable”—are less risky for business." 
@hisham_hm This is why Americans spend the most on health care, and are over-medicated, and American families go bankrupt (46% of bankruptcies?), and Americans live shorter lives than their counterparts in other wealthy countries. There's no money to be made off healthy people.
And this the model that is spreading to the rest of the world too.