A WSJ op-ed notes the effect of this misguided action:

Legacy drugs, then, aren’t medical moonshine cooked up in somebody’s bathtub; nor are they new or experimental drugs. Nonetheless, the FDA is requiring them to be put through the same regulatory wringer. Some must complete a New Drug Application, which requires clinical trials and can cost between $5 million and $10 million per legacy drug. The alternative, an Abbreviated New Drug Application, still costs over $1 million. That’s a lot of money to reinvent the wheel.

These costs are of course passed on to patients in higher prices — assuming the drugs remain on the market and their makers stay in business. The industry has small profit margins, and lacks the deep pockets and compliance teams that Big Pharma uses to navigate the FDA bureaucracy. Oh, and if one company completes a New Drug Application, the FDA simply clears the market of competitors by removing other longstanding versions from clinical use.