Cimzia®, Utilizing Enzon's PEGylation Technology, Approved in the U.S.

BRIDGEWATER, NJ – April 23, 2008 – Enzon Pharmaceuticals, Inc. (Nasdaq: ENZN) today announced that the U.S. Food and Drug Administration (FDA) has approved Cimzia®, the first and only PEGylated anti-TNFa (Tumor Necrosis Factor alpha) antibody indicated for reducing signs and symptoms of Crohn’s disease and maintaining clinical response in adult patients with moderate to severe active disease who have an inadequate response to conventional therapy.  Cimzia is currently being developed by UCB.

“Enzon continues to be committed to developing this important technology,” said Jeffrey H. Buchalter, Enzon's chairman and chief executive officer. “I am extremely pleased that our PEGylation has enabled another product which will benefit patients.”

This technology was designed by Enzon to improve versions of injectable therapeutics through the chemical attachment of polyethylene glycol or PEG.  Specific advantages of PEG include: increased efficacy, reduced dosing frequency, reduced toxicity and immunogenicity, increased stability, and enhanced solubility. Currently, there are several biologic products that utilize our proprietary PEG platform, two of which we market, Adagen and Oncaspar, others for which we receive royalties, PEG-INTRON, Pegasys, and Macugen, as well as other products currently in development.

About Cimzia® (certolizumab pegol)

Cimzia® is the first and only PEGylated anti-TNFa (Tumor Necrosis Factor alpha). Cimzia® has a high affinity for human TNF-alpha, selectively neutralizing the pathophysiological effects of TNF- alpha. Over the past decade, TNF-alpha has emerged as a major target of basic research and clinical investigation. This cytokine plays a key role in mediating pathological inflammation, and excess TNF-alpha production has been directly implicated in a wide variety of diseases. UCB is developing Cimzia® in Crohn's Disease, RA and other autoimmune disease indications. For additional information, including safety information, please refer to the Cimzia® factsheet in the "News" section of UCB's website (www.ucb-group.com).

About Enzon
Enzon Pharmaceuticals, Inc. is a biopharmaceutical company dedicated to the development, manufacturing, commercialization of important medicines for patients with cancer and other life-threatening conditions. Enzon has a portfolio of four marketed products, Oncaspar®, DepoCyt®, Abelcet® and Adagen®. The Company's drug development programs utilize several cutting-edge approaches, including its industry-leading PEGylation technology platform used to create product candidates with benefits such as reduced dosing frequency and less toxicity. Enzon's PEGylation technology was used to develop two of its products, Oncaspar and Adagen, and has created a royalty revenue stream from licensing partnerships for other products developed using the technology. Enzon also engages in contract manufacturing for several pharmaceutical companies to broaden the Company's revenue base. Further information about Enzon and this press release can be found on the Company's web site at www.enzon.com.

Forward Looking Statements

There are forward-looking statements contained herein, which can be identified by the use of forward-looking terminology such as the words "believes," "expects," "may," "will," "should,” "potential," "anticipates," "plans" or "intends" and similar expressions. Such forward-looking statements involve known and unknown risks, uncertainties and other factors that may cause actual results, events or developments to be materially different from the future results, events or developments indicated in such forward-looking statements. Such factors include, but are not limited to the timing, success and cost of clinical studies; the ability to obtain regulatory approval of products, market acceptance of, and continuing demand for, Enzon’s products and the impact of competitive products and pricing. A more detailed discussion of these and other factors that could affect results is contained in our filings with the U.S. Securities and Exchange Commission, including our annual report on Form 10-K for the period ended December 31, 2007. These factors should be considered carefully and readers are cautioned not to place undue reliance on such forward-looking statements. No assurance can be given that the future results covered by the forward-looking statements will be achieved. All information in this press release is as of the date of this press release and Enzon does not intend to update this information.

SOURCE: Enzon Pharmaceuticals, Inc.

Enzon Pharmaceuticals, Inc.
Craig Tooman
EVP, Finance and Chief Financial Officer
908-541-8777