IMPAX sued by Lilly over Cymbalta

California, USA-based IMPAX Laboratories says that drug major Eli Lilly has filed suit alleging infringement US patent no 5,023,269 in the US District Court for the Southern District of Indiana based on the company's submission of Abbreviated New Drug Application for duloxetine HCl delayed-release capsules (20mg, 30mg and 60mg), a generic of Cymbalta, to the Food and Drug Administration. In connection with this ANDA, IMPAX provided notice that its submission includes a Paragraph IV certification stating that it believes its product does not infringe any valid claim of the '269 patent.

IMPAX adds that it is aware of at least three additional law suits containing similar patent infringement claims based on the filing of ANDAs containing a Paragraph IV certification to the '269 patent. The firm's ANDA was submitted August 4, 2008, and it believes all filers submitted on that date will be entitled to 180 days of exclusivity under the applicable regulations.

Cymbalta is a selective serotonin and norepinephrine re-uptake inhibitor indicated for major depressive disorder, generalized anxiety disorder, diabetic peripheral neuropathic pain, and fibromyalgia. According to Wolters Kluwer Health, US sales of the branded drug were around $2.3 billion in the 12 months ended September 30.