The Orphan Drug Act paid for drugs nobody else would develop.

Rare diseases each affect few people, so before 1983 almost no one developed drugs for them: roughly two got approved a year. The problem was not science but economics, since the addressable market was too small to recover R&D costs.

The Orphan Drug Act, signed in January 1983, attacked the economics. It added a 25% tax credit on qualifying R&D, waived FDA user fees, and awarded seven years of marketing exclusivity to the first approved treatment for a designated disease under 200,000 US patients.

Exclusivity was the strongest lever: it let a firm act like a monopolist in a tiny market, making even modest sales worth funding. Designation also became a signal of future exclusive access, so capital flowed to drug classes that had been ignored.

Buy an orphan market with exclusivity, not with subsidies

Small patient pools never justified normal drug R&D economics

Seven-year exclusivity creates a temporary monopoly a company can price to

A tax credit and waived fees lower the cost of the risky early work

The designation mechanism lets firms de-risk, then scale, in stages

To create a market that would not exist, grant the winner a temporary monopoly rather than a one-off grant — exclusivity scales with success and costs the state nothing upfront.

From 1983 to 2022 the FDA granted 6,340 orphan designations across 1,079 rare diseases and 882 first approvals for 392 diseases, against the two-a-year baseline. Orphan approvals rose from 14 in 2000 to 77 in 2017, and in 2022 rare-disease drugs accounted for nearly half of all novel approvals.