CVS and Express Scripts filed lawsuits on Thursday seeking to overturn an Arkansas state law set to go into effect next year that would ban pharmacy benefit managers from owning pharmacies. The law puts an unconstitutional restriction on interstate commerce by burdening out-of-state companies like Express Scripts,

CVS and Express Scripts asked a federal judge on Thursday to block a law prohibiting pharmacy benefit managers from owning or operating pharmacies in Arkansas, challenging the first such restriction enacted by a state.

The massive pharmacy middlemen contend that Arkansas’ law, which requires PBMs to divest pharmacies they own in the state, flies in the face of the Constitution and would worsen healthcare access.