Enzon Pharmaceuticals, Inc has entered into a definitive agreement to sell its specialty pharmaceutical business to the Sigma-Tau Group for US$ 300 million plus an additional amount of up to US$ 27 million based on success milestones. Enzon will also receive royalties of 5 to 10 per cent on incremental net sales above a 2009 baseline amount from Enzon’s four marketed specialty pharmaceutical products through 2014.

Enzon’s specialty pharmaceutical business includes four marketed products: Oncaspar, Adagen, DepoCyt, and Abelcet, as well as the manufacturing facility in Indianapolis, Indiana which will be purchased by a US subsidiary of Sigma-Tau Pharmaceuticals, Inc (Maryland). Sigma-Tau Pharmaceuticals will distribute the products in the US market.

After the sale of these assets, Enzon’s businesses will consist of its royalties, Peg SN38 and our LNA and PEG technology platforms. “Enzon’s Board of Directors is evaluating options to return most of the value of this sale to shareholders,” stated Alex Denner, chairman. “We will refocus the company on our royalty business, pipeline, and technology platforms.”

“Sigma-Tau is a great strategic fit for this business, as they have the presence and expertise to effectively market these products in all geographic areas,” said Jeffrey H Buchalter, Enzon’s president and CEO.

Sigma-Tau is a global R&D driven, Italian-owned pharmaceutical company dedicated, among other areas, to developing and commercializing medicines for rare diseases. This acquisition will expand Sigma-Tau’s current presence in the US and in new therapeutic areas.

“Sigma-Tau is dedicated to providing novel therapeutics to patients suffering from rare diseases and other unmet medical needs,” said Claudio Cavazza, Sigma-Tau’s president. “Through the acquisition of Enzon’s specialty pharmaceutical business, we will increase our presence in the field of rare diseases with products of great value which are the result of an outstanding research activity. Sigma-Tau is determined to continue Enzon’s excellent work, especially in the field of rare diseases which is a particularly stimulating one as it aims at tackling life-threatening conditions which all too often affect the very young.”

The transaction may be deemed to constitute a sale of 'substantially all' of Enzon’s assets under Delaware law and, therefore, is conditioned upon the approval by the holders of a majority of Enzon’s outstanding shares of common stock. The transaction also is conditioned upon Sigma Tau’s receipt of funds under a bank commitment letter received by Sigma Tau and the expiration or termination of any applicable waiting periods under the Hart-Scott-Rodino Antitrust Improvements Act of 1976 and any corresponding laws of other jurisdictions. There are certain other customary conditions. The transaction is expected to be completed during the first quarter of 2010. Goldman, Sachs & Co. and Greenhill & Co. acted as financial advisors to Enzon, and Skadden, Arps, Slate, Meagher & Flom LLP acted as legal advisor to the Company.

Enzon Pharma is a biopharmaceutical company dedicated to developing, manufacturing and commercializing important medicines for patients with cancer and other life-threatening conditions.

Sigma-Tau is a leading, international, pharmaceutical group with a wholly Italian-owned capital that invests in the research, development and marketing of innovative and effective treatments to improve patient well-being and quality of life.