Pharma firm CEO insists $89,000 drug is affordable, but what’s the true cost?

CHICAGO — When Marathon Pharmaceuticals’ $89,000 price tag for a year’s supply of its newly approved muscular dystrophy drug sparked outrage earlier this month, the company’s CEO responded with another figure: $20. That’s how much he expected Duchenne muscular dystrophy patients would pay per prescription of the drug, he wrote in a letter posted on the…