Nature of Operations [Text Block] | (1) Description of Business Enzon Pharmaceuticals, Inc. (together with its subsidiaries, “Enzon” or the “Company”) receives royalty revenues from existing licensing arrangements with other companies primarily related to sales of four marketed drug products, namely, PegIntron ®, Sylatron ®, Macugen ® and CIMZIA ®. The Company also had previously received royalty revenues from licensing arrangements related to sales of Oncaspar and Adagen until the Company’s rights to receive royalties on sales of these products expired in 2014. In addition, the Company’s rights to receive royalties on sales of Macugen and CIMZIA expired in the U.S. and Great Britain in 2014. The primary source of the Company’s royalty revenues is sales of PegIntron, which is marketed by Merck & Co., Inc. (“Merck”). The Company currently has no clinical operations and limited corporate operations. The Company 73 90 80 The Company was previously dedicated to the research and development of innovative therapeutics for patients with high unmet medical needs. Beginning in December 2012, the Company’s Board of Directors (the “Board”), with outside consultants, began a review of the possible sale or disposition of one or more corporate assets or a sale of the Company. At that time, the Company suspended substantially all clinical development activities with a goal of conserving capital and maximizing value returned to the Company’s stockholders. By April 2013, the review did not result in a definitive offer to acquire the Company or all or substantially all of the Company’s assets. At the same time, the Company announced that its Board intended to distribute excess cash, expected to arise from ongoing royalty revenues, in the form of periodic dividends to stockholders. Effective June 25, 2015, the Company and Sigma-Tau Pharmaceuticals, Inc., Defiante Farmaceutica, S.A. and Sigma-Tau Finanzaria, S.P.A. (collectively “Sigma-Tau”) agreed to settle, for $ 526,128 826,128 300,000 In June 2015, the Company delivered notice to Nektar Therapeutics, Inc. (“Nektar”) asserting a breach of its Cross-License and Option Agreement with Nektar for Nektar’s failure to pay an immunity fee that the Company believes became payable to it under such agreement with respect to certain of the Company’s patents that would be infringed by Nektar’s products (or those of Nektar’s licensees). To date, Nektar has disputed the Company’s claim to an immunity fee. On August 14, 2015, the Company filed a summons and complaint against Nektar in the Supreme Court of New York for breach of contract (the “Complaint”). On October 23, 2015, Nektar filed a motion to dismiss the Complaint. As such, no amounts have been recorded as of March 31, 2016. The Company wound down its remaining research and development activities during 2013 On February 4, 2016, the Company’s Board of Directors adopted a Plan of Liquidation and Dissolution (the “Plan of Liquidation and Dissolution”), pursuant to which the Company would, subject to obtaining requisite stockholder approval, be liquidated and dissolved in accordance with Sections 280 and 281(a) of the General Corporation Law of the State of Delaware. As announced in the Company’s Current Report on Form 8-K filed on March 21, 2016, the Company’s Board of Directors has postponed seeking stockholder approval of the Plan of Liquidation and Dissolution until a later time to be determined by the Company’s Board of Directors. |