United Therapeutics Corporation, a biotechnology company focused on the development and commercialization of unique products to address the unmet medical needs of patients with chronic and life-threatening cardiovascular and infectious diseases and cancer, has confirmed that the company has received a Paragraph IV Certification Notice Letter on February 3, 2012 from Sandoz Inc. (Sandoz) advising that Sandoz has submitted an Abbreviated New Drug Application (ANDA) to the US Food and Drug Administration (FDA) requesting approval to market a generic version of the 10 mg/mL strength of Remodulin (treprostinil) injection.

In the Notice Letter, Sandoz states that it intends to market a generic version of Remodulin before the expiration of US Patent No. 5,153,222, which expires in October 2014; US Patent No. 6,765,117, which expires in October 2017; and US Patent No. 7,999,007, which expires in March 2029. Sandoz'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 Sandoz's ANDA submission.

United Therapeutics intends to vigorously enforce its intellectual property rights relating to Remodulin, including the three patents mentioned above which are listed in the FDA's Approved Drug Products List (the Orange Book).

United Therapeutics currently is reviewing the Notice Letter, which was directed to all three Orange Book-listed patents.  United Therapeutics has 45 days from receipt of the Notice Letter to commence a patent infringement lawsuit against Sandoz.  Such a lawsuit would automatically preclude the FDA from approving Sandoz'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.