Amylin Pharmaceuticals has filed a lawsuit against Eli Lilly, alleging that Lilly is engaging in "anticompetitive activity" and "breaching its strategic alliance agreements with Amylin to maximize commercialization of exenatide." According to Amylin, Lilly is planning to jointly develop and commercialize a linagliptin product with Boehringer Ingelheim that will directly compete with Amylin’s exenatide products.

Exenatide is a first-line treatment for Type II diabetes that Amylin and Eli Lilly companies developed and commercialized together as an injection under the brand name Byetta after entering into an alliance in 2002. The companies are also in the process of gaining approval for Bydureon, an extended-release formula of exenatide. Bydureon received a positive opinion from EMA’s Committee for Medicinal Products for Human Use in April this year, but it was rejected by FDA in 2010.

“The principle relief Amylin seeks is to prevent Lilly from proceeding with its plans to use the same sales force to sell both exenatide and Boehringer Ingelheim’s competitive linagliptin,” said a statement from Amylin. “Amylin selected Lilly as a partner to promote development and maximize sales of Amylin's exenatide products. We are disappointed that we could not resolve this matter amicably and that we were forced to bring legal action to protect our rights, our products and our shareholders.”

Eli Lilly announced its strategic alliance with Boehringer Ingelheim in January. In a statement, the companies said they were intending, among other projects, to jointly develop and commercialize a pipeline of oral diabetes agents and basal insulin analogues.

In response to Amylin’s allegation, Eli Lilly strongly denies any wrongdoing. “We believe the lawsuit is without merit and will vigorously defend our position,” Enrique Conterno, president of Lilly Diabetes, said in a statement. “Lilly has been and remains fully committed to fulfilling its obligations under its exenatide collaboration agreement with Amylin, as well as to complying with all laws and regulations.”

Eli Lilly added that it has devoted significant talent, resources, and know-how to the Eli Lilly–Amylin collaboration, and that the companies are planning to submit a reply to FDA’s complete response letter in the second half of 2011.

In its own statement, Amylin also emphasised that it will continue to collaborate with Eli Lilly in the development and commercialization of exenatide products.