The patent infringement action was filed at the US District Court of California requesting, among others, an order that the date of approval of Impax’s ANDA be not earlier than the expiration of Astella’s US patent on tamulosin hydrochloride, or any later date of exclusivity Astellas and BIPI are or become entitled.
In the US under a license from Astellas, BIPI has been marketing the product since 1997 under the brand name Flomax. Astellas believes that the patent is valid and intends to enforce it against infringement.
Astellas’s tamulosin hydrochloride capsules are used for the treatment of the signs and symptoms of benign prostatic hyperplasia.