Enzon Pharmaceuticals, Inc
 
	
                        685 Route 202/206
 
	
                        Bridgewater, NJ 08807
 
	
      Phone: 908 541 8600
 
	
                        Fax: 908 575-9457

                        
	
                        www.enzon.com
 




June 14, 2007

NatImmune A/S

Fruebjergvej 3 box 3 

DK-2100 Copenhagen Ø

Denmark


	
                        Re:
 	
                        Amendment to License Agreement between NatImmune A/S (“NatImmune”) and Enzon Pharmaceuticals, Inc. (“Enzon”) dated September 30, 2005 (the “Agreement”)
 




Gentlemen:

We are writing to confirm the agreement between NatImmune and Enzon that:

(i) Section E of Schedule 3.4(b) of the Agreement is deleted and replaced in its entirety by the following:

1. [**Redacted**].

The listing of the above services shall not imply an obligation on the part of Enzon to conduct or commission any activities by the third parties referred to above.

[**Redacted**]

The above described parameters shall not be modified, amended or waived by Enzon unless set forth in writing signed by Enzon’s Chief Executive Officer.

(ii) Section 2.3 of the Agreement concerning the terms for an agreement respecting the Baltic Countries, which provision was previously amended, be further amended such that “September 30, 2006” be changed to “March 31, 2008”.

All other terms of the Agreement shall remain unchanged. Capitalized words used in this letter that are not defined in this letter shall have the meanings ascribed to them in the Agreement.

Please sign below to acknowledge your agreement with the foregoing.

Yours truly,

 


	
                        ENZON PHARMACEUTICALS, INC.
 	
                         
 	
                         
 
	
                         
 	
                         
 	
                         
 
	
                         
 	
                         
 	
                         
 
	
                        By: 
 	
                        /s/  Jeffrey
      H. Buchalter
 	
                         
 	
                         
 	
                         
 
	
                         
 	
                        
 	
                         
 	
                         
 	
                         
 
	
                        Name: Jeffrey H. Buchalter
 	
                         
 	
                         
 	
                         
 
	
                        Title: Chairman, President and Chief Executive Officer
 	
                         
 	
                         
 	
                         
 




 






June 14, 2007

NatImmune
    A/S

Page 2

Accepted and agreed by:

 


	
                        NATIMMUNE A/S
 	
                         
 	
                         
 
	
                         
 	
                         
 	
                         
 
	
                        By: 
 	
                        /s/
                            Martin Bonde
 	
                         
 	
                        By: 
 	
                        /s/
                            Claus Berner Møller
 
	
                         
 	
                        
 	
                         
 	
                         
 	
                        
 
	
                        Name: Martin Bonde
 	
                         
 	
                        Name: Claus
      Berner Møller
 
	
                        Title:   Chief Executive Officer
 	
                         
 	
                        Title:   Chairman