United Therapeutics Corporation Receives Paragraph IV Notice Letter for Tyvaso

nited Therapeutics Corporation UTHR today announced receipt of a Paragraph IV Certification Notice Letter from Watson Laboratories, Inc. (Watson) advising that Watson has submitted an Abbreviated New Drug Application (ANDA) to the U.S. Food and Drug Administration (FDA) requesting approval to market a generic version of Tyvaso® (treprostinil) Inhalation Solution. In the Notice Letter, Watson states that it intends to market a generic version of Tyvaso® before the expiration of U.S. Patent No. 6,521,212, which expires in November 2018; U.S. Patent No. 6,756,033, which expires in November 2018; and U.S. Patent No. 8,497,393, which expires in December 2028. Watson's Notice Letter states that the ANDA contains a Paragraph IV Certification alleging that these patents are not valid, not enforceable and/or will not be infringed by the commercial manufacture, use or sale of the proposed product described in Watson ANDA submission. United Therapeutics intends to vigorously enforce its intellectual property rights relating to Tyvaso®. United Therapeutics currently is reviewing the Notice Letter. United Therapeutics has 45 days from receipt of the Notice Letter to commence a patent infringement lawsuit against Watson. Such a lawsuit would automatically preclude the FDA from approving Watson's ANDA for up to 30 months or until the issuance of a district court decision that is adverse to United Therapeutics, whichever occurs first.