MarketWatch -- Enzon Pharmaceuticals Inc. said Monday that it will sell its specialty pharmaceutical business to the sigma-tau Group for $300 million plus up to $27 million, based on certain milestones. Enzon said it will also receive royalties of 5% to 10% on incremental net sales above a 2009 baseline amount from Enzon’s four marketed specialty pharmaceutical products -- Oncaspar, Adagen, DepoCyt and Abelcet -- through 2014. The company expects the deal to be completed during the first quarter of 2010