Bausch takes hit in Xifaxan patent feud, potentially paving the way for Norwich's IBS-D generic

Bausch Health, after waylaying other copycats of its irritable bowel syndrome diarrhea (IBS-D) drug Xifaxan, has been dealt a blow in court. The court order potentially creates an opening for Norwich Pharmaceuticals’ proposed generic to squeeze its way onto the market.

Bausch is vowing not to let that happen.

Along with its gastroenterology unit Salix Pharmaceuticals, Bausch said Thursday that a Delaware federal court issued an oral order to scrap some patents on Xifaxan 550mg tablets.

"We strongly disagree with any conclusion that our patents are not valid and intend to file an appeal to any such order," Thomas Appio, Bausch’s CEO, said in a statement.

Meanwhile, Lisa Graver, the CEO of Norwich’s parent company Alvogen, told Fierce Pharma that the company is “very pleased with the district court’s decision, which clears a significant hurdle in the path to bringing an affordable alternative to patients taking Xifaxan for IBS-D.”

Specifically, the court upheld certain Bausch and Salix patents guarding the drug in its indication to slash the risk of overt hepatic encephalopathy (HE) recurrence but ruled that IP on the composition and use of the drug in IBS-D was invalid. Besides HE recurrence, Xifaxan is also approved for traveler's diarrhea.

Bausch says it will contest the decision at the U.S. Court of Appeals for the Federal Circuit.

In theory, Norwich Pharmaceuticals—battling in court with Bausch since 2020—could try to forego pursuing the drug in liver disease complications and focus on an IBS nod alone. Nevertheless, Bausch expects the court to enjoin Norwich’s pending generic application until Xifaxan’s HE patents lapse in 2029, the company said in a release.

“The company intends to vigorously oppose any attempt by Norwich to remove the HE safety data from its [abbreviated new drug application] in an effort to avoid the Xifaxan [liver disease complication] patents,” Bausch said.

“Until an approval of a revised ANDA is granted by the FDA and the expected injunction modified by the Court, Norwich is not permitted to launch a generic equivalent of Xifaxan,” Bausch continued.

Bausch noted in its release that it’s previously entered settlement agreements with Teva Pharmaceutical, Sun Pharmaceuticals and Novartis’ generics division Sandoz to stave off the launch of a Xifaxan copycat until 2028.

Xifaxan is one of Bausch’s key drugs, alongside its constipation and IBS with constipation med Trulance, which was first approved in 2017. All told, the company reported full-year 2021 revenues of $8.434 billion. While Bausch didn’t break out specific sales figures for Xifaxan, it did note that the med’s revenues jumped 11% for the full year compared to 2020.