Pharma unit could get green light to launch IBS generic
Dispute centres on Xifaxan, used to treat irritable bowel syndrome | ‘Significant hurdle’ cleared in bringing drug to market | Bausch wins partial victory after Alvogen subsidiary failed to show that patent claims were obvious.
A Delaware judge has potentially cleared the way for Norwich Pharmaceuticals, an Alvogen subsidiary, to launch a proposed generic of Bausch Health’s drug Xifaxan (rifaximin) for treating irritable bowel syndrome.
In an oral order handed down yesterday, August 1, Judge Richard Andrews of the US District Court for the District of Delaware directed Norwich and Bausch Health (and its subsidiary Salix Pharmaceuticals) to file a joint proposed final judgment by tomorrow, August 3.
Xifaxan is indicated for reduction in risk of overt hepatic encephalopathy (HE) recurrence in adults and treatment of irritable bowel syndrome with diarrhoea (IBS-D) in adults.
Setting out the court’s conclusions in the oral order, Andrews said that Norwich's Abbreviated New Drug Application (ANDA) would infringe the asserted IBS-D and polymorph patent claims if they were valid. The court also concluded that the asserted polymorph and IBS-D claims are invalid as obvious.
Partial win
However, in a partial victory for Bausch, the court also found that Norwich, which was represented by Axinn, had failed to show that the asserted HE claims were obvious and that they lacked adequate written description.
In February 2020, Alvogen sent its notice letter to Bausch, advising it that Norwich had submitted its ANDA to the US Food and Drug Administration and alleging that certain claims of the Xifaxan patents were invalid, unenforceable, and/or not infringed.
The following month, in March 2020, Bausch and Salix accused Norwich of infringing 23 patents.
Lisa Graver, CEO of Alvogen, said: “We are 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.”
The court has not yet entered any final judgement. However, Bausch said that subject to Norwich’s removal of the HE indication and data from its ANDA, it is expected that the court will enjoin Norwich's pending ANDA until the Xifaxan HE patents expire in 2029.
Thomas Appio, CEO of Bausch Health, said he was disappointed with the development.
“We strongly disagree with any conclusion that our patents are not valid and intend to file an appeal to any such order,” he said.
“As a leader in gastrointestinal health, protecting our IP is essential to our ability to continue to develop innovative therapies. We intend to vigorously pursue all available options to challenge any final ruling, while also continuing to drive growth and innovation for our Xifaxan franchise.”
Bausch intends to file an appeal immediately after any final order is issued, assuming it is consistent with the oral order.
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