Italy’s Sigma-Tau has signed an agreement to buy Enzon Pharmaceuticals of the USA’s specialty drugs business.

Under the terms of the deal, Sigma-Tau is splashing out $300 million, plus potential milestone payments of up to $27 million and royalties of 5%-10% on sales above “a 2009 baseline amount from its four marketed specialty pharmaceuticals through 2014”. Those products are Oncaspar (pegaspargase) for the treatment of acute lymphoblastic leukaemia, Adagen (pegademase bovine) to treat patients afflicted with a type of severe combined immunodeficiency disease (also known as the "bubble boy disease"), DepoCyt, a sustained-release formulation of cytarabine approved for lymphomatous meningitis and the antifungal Abelcet (amphotericin B).

The deal, which is expected to close in the first quarter of 2010, also includes a manufacturing facility in Indianapolis. Enzon added that after the sale of these assets, its businesses will consist of royalties, Peg SN38 (an active metabolite of the cancer drug irinotecan) and its locked nucleic acid and PEGylation technology platforms.

The deal will expand Sigma-Tau’s efforts in the USA and president Claudio Cavazza added that “we will increase our presence in the field of rare diseases with products of great value”.