new york democratic u.s. senator claire mccaskill thursday say draft bill state tribal sovereign immunity use block u.s. patent trademark office review patent drugmaker allergan plc make deal transfer patent native american tribe two weeks ago order shield review mccaskill response follow bipartisan u.s. house representatives committee decision investigate deal early week previous call democratic senators probe think person would look company say illegal well agree mccaskill say statement congress never imagine tribes would allow use pharmaceutical company avoid challenge patent bill shut practice others follow suit allergan immediately available comment allergan say last month transfer patent blockbuster dry eye medication restasis new york saint regis mohawk tribe agree exclusively license back company exchange ongoing payments tribe issue statement express outrage mccaskill move accuse senator engage double standards say propose legislation specifically target indian tribes yet exempt state universities sovereign governments engage ipr inter part review process allergan argue legal maneuver aim remove administrative patent challenge inter part review u.s. patent trial appeal board challenge federal court drugmaker say believe patent subject ipr process allergan call flaw break tribe sovereign immunity company still face challenge patent federal court senator mccaskill draft bill response allergan patent maneuver