Filed by Enzon Pharmaceuticals, Inc.
                                    Pursuant to Rule 425 under the
                                    Securities Act of 1933 and deemed filed
                                    pursuant to Rule 14a-12 of the
                                    Securities Exchange Act of 1934

                                    Commission File No. 000-12957
                                    Subject Company: Enzon Pharmaceuticals, Inc.
                                                     NPS Pharmaceuticals, Inc.

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FOR IMMEDIATE RELEASE               Contact:  Susan Mesco
                                    Enzon, Inc.
                                    Director, Investor Relations
                                    732-980-4577

                                    David L. Clark
                                    Vice President, Operations
                                    NPS Pharmaceuticals, Inc
                                    801-583-4939

                                    Ernie Knewitz (Media)
                                    Noonan Russo Presence Euro RSCG
                                    212-845-4253

                  NPS PHARMACEUTICALS AND ENZON PHARMACEUTICALS

                            AGREE TO MERGER OF EQUALS

        Science, Pipeline, Products...Creating a New Biotechnology Leader

         Salt Lake City, UT, & Bridgewater, NJ, Feb. 20, 2003 -- NPS
Pharmaceuticals, Inc. (Nasdaq: NPSP) and Enzon Pharmaceuticals, Inc. (Nasdaq:
ENZN) announced today that they have signed a definitive agreement to a merger
of equals in a stock-for-stock transaction with a value of approximately $1.6
billion. Under terms of the agreement, each Enzon shareholder will receive
0.7264 shares of the new company's common stock for each Enzon share owned. Each
NPS shareholder will receive 1.00 share for each NPS share owned. The
combination will create a powerful, integrated biotechnology company featuring
demonstrated research capabilities, extensive drug development and manufacturing
expertise, an innovative product pipeline, established commercial
infrastructure, and a strong and growing revenue base.

         NPS and Enzon will combine management and scientific talent to create a
new biotechnology leader. The new company will have one of the industry's
deepest and most innovative drug discovery and development pipelines addressing
opportunities in areas of unmet therapeutic need, combined with a number of
powerful revenue generators and over $300 million of cash. The company will be
headquartered in Bridgewater, New Jersey, and will maintain major research,
development and manufacturing facilities in Salt Lake City, Utah; Toronto,
Canada; Indianapolis, Indiana, and additional locations in New Jersey. Dr.
Hunter Jackson, currently the Chairman, President and CEO of NPS, will serve as
Executive Chairman of the new company, and Arthur J. Higgins, Enzon's Chairman,
President and CEO, will serve as the new company's Chief Executive Officer.
Teams from both companies have begun planning the post-merger integration
process, which will include introducing a new name.



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         "Combining NPS's tremendous research and development capabilities with
Enzon's commercial and operating expertise will empower us to create a truly
integrated team addressing all aspects of operations. Our combined strength will
enable us to maximize success across a broad range of opportunities," said Dr.
Jackson. Mr. Higgins added, "Our new entity will possess all of the necessary
elements to emerge as a new biotechnology leader. With a high-potential product
pipeline, a growing revenue base, and a commitment to disciplined execution, we
are positioned for sustainable growth and expect to reach profitability in 2006
or before."
                                Marketed Products
         Building on its established commercial organization, including a
hospital-based sales force and a focused specialty oncology sales team, the
newly formed company will immediately benefit from estimated revenues of
approximately $200 million for the year ending December 31, 2003. Company
revenues will be driven by four internally marketed products, as well as free
cash flow due to royalties on PEG-INTRON(R). The line-up of marketed products
includes:

         o     PEG-INTRON: a longer-acting form of INTRON(R) A (interferon
               alfa-2b, recombinant) is used in the treatment of chronic
               hepatitis C. This product uses proprietary PEG technology
               developed by Enzon and is marketed by Schering- Plough.

         o     ABELCET(R): an antifungal used in hospitals to treat patients
               with invasive fungal infections related to cancer, organ
               transplantation and other conditions.




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         o     ONCASPAR(R): a PEG-enhanced version of a naturally occurring
               enzyme called L-asparaginase used in conjunction with other
               chemotherapeutics to treat patients with acute lymphoblastic
               leukemia.

         o     DEPOCYT(R): an injectable chemotherapeutic for the treatment
               of patients with lymphomatous meningitis.

         o     ADAGEN(R): a PEG-enhanced enzyme replacement therapy that is
               used for the treatment of severe combined immunodeficiency
               disease, or SCID, also known as the "Bubble Boy Disease."

         Its revenue stream, in combination with a strong cash position, will
create the unusual but invaluable flexibility to selectively choose how it
commercializes its late stage pipeline, and optimizes the value of its product
development opportunities.

                              Pipeline Highlights

         A distinguishing characteristic of the company is its combined pipeline
addressing significant unmet medical needs, including:

         o     Two Phase III programs: PREOS(TM) for the treatment of
               osteoporosis, and cinacalcet HCl, which is being developed by
               Amgen for the treatment of secondary hyperparathyroidism.

         o     Three Phase II programs: PROTHECAN(R) for various solid
               tumors; ALX-0600 for Short Bowel Syndrome and other
               gastrointestinal disorders; and cinacalcet HCl for primary
               hyperparathyroidism.

         o     Over 10 specific early stage programs addressing unmet medical
               needs in endocrinology, immunology, oncology, neurology, and
               gastroenterology. Upon completion of the merger, the candidate
               portfolio will be reviewed and resources will be focused on
               the most promising programs.




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                               Research Expertise

         Scientifically, the new company will emphasize and build on its talents
and experience in discovery research. Proven research platforms of the combined
company will include small molecule discovery efforts targeting calcium
receptors, metabotropic glutamate receptors (mGluRs), and other G-protein
coupled receptors, plus technology to attach polyethylene glycol, or PEG, to
therapeutic molecules, and the SCA (single-chain antibody) program. Work in
these areas has led to a number of proprietary opportunities and joint research
programs, which will continue to be pursued by the new company. On-going
collaborations include calcilytics with GlaxoSmithKline, mGluRs with
AstraZeneca, drug delivery with Nektar Therapeutics and SkyePharma, and SCA with
Micromet. The goal of the new company's focus on discovery research is to move a
continuing stream of new product candidates into clinical development.

                                The Transaction

         The merger agreement has been unanimously approved by the boards of
directors of both companies, and is subject to certain closing conditions,
including approval by the shareholders of NPS and Enzon. Upon closing, which is
expected in June 2003, the board of directors will be composed of six
individuals from NPS's board and four from Enzon's, including both Dr. Jackson
and Mr. Higgins.

         In the transaction, Morgan Stanley advised NPS and SG Cowen advised
Enzon.

         Dr. Jackson and Mr. Higgins will discuss the proposed merger with
analysts and investors in a webcasted conference call at 10:00 a.m. EST.
Interested parties can join the webcast at www.videonewswire.com/newco/022003,
or dial into the conference call at 800-231-5571, locally, or 973-582-2703,
internationally.

         NPS Pharmaceuticals discovers, develops and intends to commercialize
small molecules and recombinant proteins as drugs, primarily for the treatment
of bone and mineral, metabolic, gastrointestinal, and central nervous system
disorders.



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         Enzon Pharmaceuticals is a biopharmaceutical company dedicated to the
discovery, development and commercialization of therapeutics to treat
life-threatening diseases. The company has developed three marketed products,
including PEG-INTRON, marketed by Schering-Plough. Enzon's product-focused
strategy includes an extensive drug development program that leverages the
Company's PEG modification and single-chain antibody (SCA(R)) technologies.
Internal research and development efforts are complemented by strategic
transactions that provide access to additional products, projects and
technologies. Enzon has several drug candidates in various stages of
development, independently and with partners.

      Cautionary Statement For The Purpose Of The "Safe Harbor" Provisions
            Of The Private Securities Litigation Reform Act Of 1995

         This press release contains forward-looking statements within the
meaning of the "safe harbor" provisions of the Private Securities Litigation
Reform Act of 1995. These statements are based on management's current
expectations and beliefs and are subject to a number of factors and
uncertainties that could cause actual results to differ materially from those
described in the forward-looking statements. The forward-looking statements
contained in this presentation include statements about future financial and
operating results and the proposed NPS/Enzon merger. These statements are not
guarantees of future performance, involve certain risks, uncertainties and
assumptions that are difficult to predict, and are based upon assumptions as to
future events that may not prove accurate. Therefore, actual outcomes and
results may differ materially from what is expressed herein. For example, if
either of the companies do not receive required stockholder or governmental
approvals or fail to satisfy other conditions to closing, the transaction will
not be consummated. In any forward-looking statement in which NPS or Enzon
expresses an expectation or belief as to future results, such expectation or
belief is expressed in good faith and believed to have a reasonable basis, but
there can be no assurance that the statement or expectation or belief will
result or be achieved or accomplished. The following factors, among others,
could cause actual results to differ materially from those described in the
forward-looking statements: the risk that the NPS and Enzon businesses will not
be integrated successfully; costs related to the proposed merger, failure of the
NPS or Enzon stockholders to approve the proposed merger; and other economic,
business, competitive and/or regulatory factors affecting NPS' and Enzon's
businesses generally as set forth in NPS's and Enzon's filings with the SEC,
including their Annual Reports on Form 10-K for their respective most recent
fiscal years, especially in the Management's Discussion and Analysis section,
their most recent Quarterly Reports on Form 10-Q and their Current Reports on
Form 8-K. NPS and Enzon are under no obligation to (and expressly disclaim any
such obligation to) update or alter their forward-looking statements whether as
a result of new information, future events or otherwise.

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                   Additional Information And Where To Find It

         In connection with the proposed NPS/Enzon merger, NPS, Enzon and
Momentum Merger Corporation (which will be renamed by NPS and Enzon in
connection with the proposed merger) intend to file a joint proxy
statement/prospectus with the Securities and Exchange Commission (the "SEC") in
connection with the transaction described herein. INVESTORS AND SECURITY HOLDERS
ARE URGED TO READ THE JOINT PROXY STATEMENT/PROSPECTUS WHEN IT BECOMES AVAILABLE
BECAUSE IT WILL CONTAIN IMPORTANT INFORMATION ABOUT THE TRANSACTION DESCRIBED
HEREIN. Investors and security holders may obtain a free copy of the joint proxy
statement/prospectus (when it is available) and other documents filed by NPS and
Enzon with the SEC at the SEC's web site at www.sec.gov or by contacting NPS at
801-583-4939 and through NPS' website at www.npsp.com, or by contacting Enzon at
908-541-8678 and through Enzon's website at www.enzon.com.

         NPS and its directors and executive officers may be deemed to be
participants in the solicitation of proxies from the stockholders of NPS and
Enzon in connection with the transaction described herein. Information regarding
the special interests of these directors and executive officers in the
transaction described herein will be included in the joint proxy
statement/prospectus described above. Additional information regarding these
directors and executive officers is also included in NPS' proxy statement for
its 2002 Annual Meeting of Stockholders, which was filed with the SEC on or
about April 19, 2002. This document is available free of charge at the SEC's web
site at www.sec.gov or by contacting NPS at 801-583-4939 and through NPS's
website at www.npsp.com.

         Enzon and its directors and executive officers also may be deemed to be
participants in the solicitation of proxies from the stockholders of Enzon and
NPS in connection with the transaction described herein. Information regarding
the special interests of these directors and executive officers in the
transaction described herein will be included in the joint proxy
statement/prospectus described above. Additional information regarding these
directors and executive officers is also included in Enzon's proxy statement for
its 2002 Annual Meeting of Stockholders, which was filed with the SEC on or
about October 28, 2002. This document is available free of charge at the SEC's
web site at www.sec.gov or by contacting Enzon at 908-541-8678 and through
Enzon's website at www.enzon.com.

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