Challengers of brand name drug patents would have to choose between litigating under Hatch-Waxman or through inter partes review under legislation introduced in both the Senate and House on Wednesday.

The 1984 Hatch-Waxman Act allowed generic drugmakers to challenge branded drug patents under two accelerated pathways, regulated by the FDA and litigated in federal courts. But the 2012 American Invents Act allowed challenges via inter partes reviews before the PTO’s Patent Trial and Appeal Board — an administrative hearing with a  lower burden of proof than a district court.

Sen. Orrin Hatch (R-Utah) and two colleagues have introduced a set of proposed reforms that they say will bring clarity and prevent arbitrage by making patent challengers choose one route or the other.