Nature of Operations [Text Block] | (1) Description of Business Enzon Pharmaceuticals, Inc. (together with its subsidiary, “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 ®. 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. Royalty revenues from sales of PegIntron accounted for approximately 61 83 70 80 80 79 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. The Company ended its remaining research and development activities during 2013 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. The case was remanded to the trial court for further proceedings. As such, no amounts have been recorded as of September 30, 2016. On February 4, 2016, the Company entered into (i) an agreement with the landlord (the “Landlord”) of our leased property at 20 Kingsbridge Road, Piscataway, New Jersey (the “Leased Property”) and the Company’s subtenant and (ii) a letter agreement with the Landlord (the “Letter Agreement”). Pursuant to a Surrender and Release Agreement, (i) our lease agreement (the “Prime Lease”) with the Landlord terminated effective as of February 4, 2016 (the “Termination Date”) and (ii) our sublease agreement with the subtenant became a direct lease between the Landlord and the subtenant effective as of the Termination Date. Pursuant to the Letter Agreement, from and after the Termination Date, the Landlord agreed to perform all of the Company’s obligations under the sublease, the Landlord waived all claims against the Company in connection with the lease, the sublease or the Leased Property and the Landlord has released the Company from all liability in connection with the lease and the sublease and, in exchange therefor, on the Termination Date, the Company paid $ 4.25 204,000 Commencing on March 1, 2016, the Company changed the location of its principal executive offices to 20 Commerce Drive, Suite 135, Cranford, New Jersey, 07016. The Company entered into an office service agreement with Regus Management Group, LLC (“Regus”) for use of office space at this location effective March 1, 2016. The term of the agreement will continue until February 28, 2017 2,418 1,209 On February 4, 2016, the Board 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 Board has postponed seeking stockholder approval of the Plan of Liquidation and Dissolution until a later time to be determined by the Board. The Company’s common stock was delisted from Nasdaq on May 20, 2016 because the Company no longer met the requirement to maintain a minimum bid price of $ 1.00 |