Unassociated Document


    Exhibit
      10.1

    


    WAIVER
      AND ACKNOWLEDGEMENT

    


    March
      30,
      2007

    


    


    Reference
      is made to the sale and issuance by Alteon Inc., a Delaware corporation (the
      “Company”),
      of
      its convertible promissory notes and warrants pursuant to the transactions
      contemplated by (i) that certain Convertible Note and Warrant Purchase Agreement
      dated January 11, 2007, by and among the Company and the lenders named therein
      (the “Lenders”)
      (the
“Purchase
      Agreement”),
      (ii)
      those certain convertible promissory notes, each dated January 11, 2007, in
      an
      aggregate principal amount of $3,000,000 issued to the Purchasers (the
“Promissory
      Notes”),
      (iii)
      those certain warrants to purchase shares of the Company’s common stock, $0.01
      par value per share (“Common
      Stock”),
      dated
      January 11, 2007, issued to the Purchasers (the “Warrants”),
      (iv)
      that certain Security & Guaranty Agreement by and among the Company,
      HaptoGuard, Inc., a wholly owned subsidiary of the Company (“HaptoGuard”),
      and
      Baker Bros. Advisors, LLC, as collateral agent, dated January 11, 2007 (the
      “Security
      and Agreement”)
      and
      (v) that certain Intellectual Property Security Agreement by and among the
      Company, HaptoGuard and Baker Bros. Advisors, LLC, as collateral agent, dated
      January 11, 2007 (the “IP
      Security Agreement”
and
      together with the Purchase Agreement, the Promissory Notes, the Warrants and
      the
      Security Agreement, the “Note
      Documents”).
      Capitalized terms used herein and not defined will have the meaning ascribed
      to
      them in the Purchase Agreement.

    


    The
      undersigned Purchasers and Collateral Agent, by their signature below, each
      hereby:

    


    
      	 	
              a)

            	
              subject
                to clause b) below, waive compliance with any agreement, covenant
                or
                obligation of or by the Company set forth in any of the Note Documents
                with respect to (i) the Company entering into definitive documents
                for the
                Preferred Financing by March 31, 2007; (ii) the Company holding the
                Stockholder Meeting on or prior to April 30, 2007 (which date will
                be
                extended to May 31, 2007 if the SEC reviews and comments on the proxy
                statement relating to the Stockholder Meeting) or (iii) the Maturity
                Date
                of each of the Promissory Notes; 

            


    

    


    
      	 	
              b)

            	
              acknowledge
                and agree that (i) the Company may enter into definitive documents
                for the
                Preferred Financing at anytime prior to April 15, 2007, and (ii)
                the
                Company hold the Stockholder Meeting at any time on or prior to May
                15,
                2007 (which date will be extended to June 15, 2007 if the SEC reviews
                and
                comments on the proxy statement relating to the Stockholder Meeting),
                without being in breach of or triggering any event of default under
                any of
                the Transaction Documents, and (iii) the Maturity Date of each of
                the
                Promissory Notes is hereby extended to June 18,
                2007.

            


    

    


    
      
         

      

      
         

        
          

        

      

      
         

      

    

    In
      consideration of the foregoing waivers, acknowledgments and agreements, the
      Company, the Purchasers and the Collateral Agent further agree that, with
      respect to that certain Memorandum of Terms dated January 4, 2007, the date
      of
      March 31, 2007 in the section entitled “Exclusivity and Confidentiality” shall
      be extended to April 15, 2007.

    


    The
      Purchasers and Collateral Agent expressly reserve all rights and remedies
      available to them as a result of any breach or default relating to the items
      described in clauses a) and b) from or after the date hereof, as well as any
      breach or default of any other provision of the Note Documents which may have
      occurred at any time prior to, or may occur on or after, the date hereof.


    


    The
      Company hereby acknowledges and agrees that the execution and delivery by the
      Purchasers and Collateral Agent of this Waiver and Acknowledgment shall not
      be
      deemed to create a course of dealing or otherwise obligate the Purchasers or
      Collateral Agent to execute similar waivers under the same or similar
      circumstances in the future.

     

    


    [remainder
      left intentionally blank]

    


    
      
         

      

      
         

        
          

        

      

      
         

      

    


    The
      undersigned hereby executes this Waiver and Acknowledgment as of the date first
      set forth above. 

     

    
      	BAKER
              BROS. ADVISORS, LLC,
              	 	 
	as
              Collateral Agent	BAKER/TISCH
              INVESTMENTS, L.P.
	 
 	 
 	 
 
	 	By:  	Baker/Tisch
              Capital, L.P.,
	 	 	its general partner 
	 	   	 
	 	By: 	Baker/Tisch Capital (GP), LLC, 
	 	its general
              partner


    

    
      
        	 
 	 	 
 	 
 
	By:  
                	
                /s/ Felix Baker, Ph.D. 

                
                  

                

                Name: Felix Baker, Ph.D.

                Title: Managing Member

              	By:  	
                /s/
                  Felix Baker, Ph.D.

                
                  

                

                Name: Felix Baker, Ph.D

                Title: Managing
                  Member

              


      

      	 	 	 
	 	 
	 	BAKER
              BIOTECH FUND I, L.P.
	 
 	 
 	 
 
	 	By:  	Baker
              Biotech Capital, L.P.,
	 	 	its general partner 
	 	 	 
	 	By:  	Baker Biotech Capital (GP), LLC,  
	 	
              its
                general partner

            


      	 	 	 
	 	 
 	 
	 	By:  	/s/ Felix
              Baker, Ph.D.
	 	
              
Name:
              Felix Baker, Ph.D.
	 	Title:
              Managing Member


      	 	 	 
	 	 
	 	Baker
              Brothers Life Sciences, L.P.
	 
 	 
 	 
 
	 	By:  	Baker
              Brothers Life Sciences Capital, L.P.
	 	 	its general partner
	 	 	 
	 	By:	Baker Brothers Life Sciences Capital (GP),
              LLC  
	 	 	is general partner
	 	 	 
	 	By: 	/s/Felix
              Baker, Ph.D.
	 	
              
Name:
              Felix Baker, Ph.D.
	AGREED
              AND
              ACCEPTED:	Title:
              Managing Member
	 	 


      	ALTEON
              INC.	14159,
              L.P. 
	 	 	 
 	 
 
	
               

              By:  
                

            	
               

              /s/ Noah Berkowitz.

              
                

              

              Name: Noah Berkowitz

              
                Title:
                  President 

              

            	
              By:  

               

              By:

            	
              14159
                Capital, L.P., its general partner

               

              14159 Capital (GP), LLC, is general
                partner

            


      	 	 	 
	 
 	 
 	 
 
	 	By:  	/s/ Felix
              Baker, Ph.D.
	 	
              
Name:
              Felix Baker, Ph.D.
	 	
              Title:
                Managing Member