Bausch Health (BHC) Stock Plunges 50% on Patent News While pharmaceutical companies often face great risks in the clinical testing arena, they can also suffer extraordinary setbacks in the courtroom, as Bausch Health (NYSE: BHC ) unfortunately demonstrated today. Authorities halted trading on BHC stock as it plunged 50% during the morning session. An unfavorable ruling on Bausch’s patent battle against Norwich Pharmaceuticals – which aims to develop a generic version of the former’s Xifaxan drug – severely clouded BHC’s viability. Purely from a legal perspective, the court’s decision regarding the status of Xifaxan, a therapeutic for treating irritable bowel syndrome with diarrhea and liver disease, was a mixed bag. Federal district court Judge Richard G. Andrews ruled that Norwich’s proposed generic “will induce infringement of the asserted [hepatic encephalopathy] patent claims, and would induce infringement of the asserted [irritable bowel syndrome with diarrhea], and Polymorph patent claims if they were valid.” Further, Judge Andrews stated, “Norwich has failed to show that the asserted HE claims are obvious and that they lack adequate written description.