Generic drug manufacturer Lupin Pharmaceuticals will pay $90 million to resolve patent infringement claims brought by Astellas Pharma Inc. over the blockbuster bladder medication Myrbetriq, bringing an end to years of litigation in Delaware federal court.

The settlement terms were disclosed in a securities filing Lupin submitted to the National Stock Exchange of India. The company said it will make an upfront payment of $75 million, with the remaining balance structured through licensing fees tied to a commercial agreement that runs through September 2027.

According to Lupin, the deal allows it to keep marketing its generic version of mirabegron, the active ingredient in Myrbetriq, without further legal uncertainty.

“This settlement resolves Lupin’s pending litigation with Astellas and allows Lupin to continue to sell its mirabegron product,” the company said in its filing.

The announcement followed a joint request by both companies asking a Delaware federal judge to enter a consent judgment formally closing the case. Under that agreement, Lupin acknowledged that its abbreviated new drug application submitted to the U.S. Food and Drug Administration infringed at least one claim from each of four Astellas patents protecting the branded drug.

The patents cover modified-release pharmaceutical compositions for mirabegron and have been central to Astellas’ efforts to shield Myrbetriq from generic competition.

The litigation has had a lengthy procedural history. The case returned to the trial court after the U.S. Court of Appeals for the Federal Circuit vacated a previous ruling that had invalidated one of the patents. That appellate decision revived portions of Astellas’ claims and strengthened its position in settlement talks.

Astellas originally filed suit against several generic manufacturers, including Lupin and Zydus Pharmaceuticals, accusing them of attempting to launch competing versions of the drug before patent protections expired. Those cases were consolidated in the District of Delaware.

Some defendants have already reached agreements with Astellas. Court records show that Sandoz settled soon after the Federal Circuit ruling, and the dispute with Lupin now marks another resolution among the group.

In a statement, Astellas said the agreement ends all disputes with Lupin relating to Myrbetriq and mirabegron but noted that litigation with other generic challengers remains ongoing. The financial details of the settlement, aside from Lupin’s public disclosure, were not released.

Myrbetriq is widely prescribed for overactive bladder and generates significant revenue for Astellas, making patent protection a high-stakes issue. Patent settlements in the pharmaceutical sector often determine when lower-cost generics can enter the market, directly affecting pricing and competition.

The case is Astellas Pharma Inc. et al. v. Lupin Ltd. et al., No. 1:20-cv-01589, in the U.S. District Court for the District of Delaware.