Eli Lilly’s blockbuster drug for osteoporosis, Forteo, could face generic competition from Indian drugmaker Sun Pharmaceuticals if the company can get a federal judge to declare that a Lilly patent won’t be infringed.
Sun Pharmaceuticals, the largest drugmaker in India, filed suit this month against Lilly in U.S. District Court in Indianapolis, seeking a declaration that the manufacture and sale of its generic version of Forteo won’t infringe on Lilly’s patent covering the drug’s spring-loaded injector pen.
Under patent law, Lilly could sue Sun at any time, unless the generic drugmaker gets a declaratory judgment.
Lilly did not immediate respond to IBJ regarding the lawsuit.
Forteo had worldwide sales of $1.05 billion last year, down 21% from a year earlier. Lilly has said the patent covering the injection device used to administer the drug expires in March 2025.
The dispute does not involve patents over the drug itself. According to Lilly’s 2020 annual report, the formulation patents for Forteo expired in 2018, and the use patents expired in 2019 in major European markets and the U.S. Both the formulation patent and the use patent expired in August 2019 in Japan.
“We expect further volume decline as a result of the anticipated entry of generic and biosimilar competition following the loss of patent exclusivity in these markets,” Lilly’s annual report said. “In the aggregate, we expect that the decline in revenue will have a material adverse effect on our consolidated results of operations and cash flows.”
Sun wants to get approval from the U.S. Food and Drug Administration for the commercial manufacture, use, and sale of a generic version of Forteo prefilled pens.
On July 28, 2021, Lilly filed a complaint against Sun for infringement of the patent on its injectable pen. Lilly alleged two counts of patent infringement.
Sun claims it has engaged in numerous discussions with Lilly over the patent issue. It said that Lilly filed a lawsuit claiming patent infringement, but chose to dismiss the lawsuit without prejudice, but did not explain to Sun why it dismissed its lawsuit or expressly disavow its infringement allegations.
“Sun therefore is under a cloud of litigation uncertainty,” Sun’s lawsuit said. “…Sun is entitled to and seeks to lift this cloud of uncertainty.”