Setback for Alvogen in approval bid for IBS generic
District court denies Norwich’s motion to compel FDA to grant approval for its version of popular IBS medication | Court also grants summary judgment in favour of FDA and Norwich’s competitor.
Alvogen subsidiary, Norwich Pharmaceuticals has faced a setback in its efforts to secure US regulatory approval for its generic version of an irritable bowel syndrome (IBS) treatment.
Norwich's motion to compel the US Food and Drug Administration (FDA) to immediately grant final approval for Norwich's abbreviated new drug application (ANDA) for Xifaxan (rifaximin) was denied by the US District Court for the District of Columbia on November 1, 2023.
The court also granted summary judgment in favour of the FDA and Salix Pharmaceuticals.
Case background
Salix and Norwich have been entwined in a legal dispute over Xifaxan since 2019.
Norwich wanted to introduce a generic version of Xifaxan but the company had to secure final approval from the FDA for its ANDA before bringing it to the market.
In Norwich's initial ANDA submission, Salix identified 23 patents that are protected by Salix and used in Xifaxan.
This was considered patent infringement by Salix, prompting it to file a patent infringement suit in the US District Court for the District of Delaware.
The Delaware district court ruling invalidated two drug substance patents and two method-of-use patents in the IBS-D owned by Salix.
However, it upheld Salix's three HE method-of-use patents, deeming them valid and infringed upon.
Consequently, the court ordered that the effective date for FDA approval of Norwich's ANDA should not be earlier than the expiration of the HE method-of-use patents, which is October 2, 2029.
Norwich returned to the FDA with an amended ANDA, which excluded the HE indication from its proposed label.
It also filed a motion to modify the judgment to allow the FDA to approve the amended ANDA without delay, however, the district court rejected the motion
Both pharma companies appealed the Delaware District Court’s decision to the Federal Circuit, which remains pending.
After both parties appealed to the Federal Circuit, the FDA granted tentative approval of Norwich's ANDA but refused to grant final approval, complying with the district court's interpretation of the final judgment.
Norwich then challenged the FDA's decision to grant only tentative, rather than final, approval for its amended ANDA.
The Alvogen subsidiary sought injunctive and declaratory relief, demanding that the FDA immediately grant final approval for the amended ANDA.
Norwich asserted that the FDA misinterpreted the district court's order, arguing that it applied only to the company's original ANDA. Simultaneously with filing the suit, Norwich sought a preliminary injunction.
This week, the FDA and Salix successfully opposed this motion, with the FDA filing for summary judgment and Salix requesting both summary judgment and dismissal.
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