Exhibit
      10.1

    


    OMNIBUS
      AMENDMENT

    


    This
      OMNIBUS AMENDMENT
      (this
      “Amendment”)
      dated
      June 1, 2007 is entered into by and among Alteon Inc., a Delaware corporation
      (the “Company”),
      and
      the purchasers (the “Purchasers”)
      identified on the signature pages to that certain Note and Warrant Purchase
      Agreement dated as of January 11, 2007 (the “Note
      Purchase Agreement”).
      

    


    WHEREAS,
      in connection with the execution and delivery of the Note Purchase Agreement,
      the Company issued and sold to the Purchasers (i) an aggregate of $3,000,000
      of
      its Senior Convertible Secured Promissory Notes (the “Prior Notes”),
      each
      dated January 11, 2007, and (ii) warrants (the “Warrants”),
      each
      dated January 11, 2007, to purchase and aggregate of 25,734,453 shares of the
      common stock, $0.01 par value per share (the “Common
      Stock”)
      of the
      Company; 

    


    WHEREAS,
      on March 30, 2007, the Company and the Purchasers entered into a Waiver and
      Acknowledgment to delay certain dates set forth in the Note Purchase Agreement
      and related instruments;

    


    WHEREAS,
      the Company, the Purchasers and other investors have entered into a Series
      B
      Preferred Stock and Warrant Purchase Agreement dated April 5, 2007 (the
“Preferred Purchase
      Agreement”);
      

    


    WHEREAS,
      effective April 30, 2007, the Company and the Purchasers entered into an
      Amendment No. 1 to Registration Rights Agreement to delay certain dates set
      forth in that certain Registration Rights Agreement, dated as of January 11,
      2007 (the “Registration
      Rights Agreement”,
      and
      together with the Note Purchase Agreement, the Notes and the Warrants, the
      “Note
      Purchase Documents”);

    


    WHEREAS,
      the Company has requested, and the Purchasers have agreed to fund, an additional
      aggregate principal amount of $3,000,000 in consideration of new Senior
      Convertible Secured Promissory Notes dated the date hereof in substantially
      the
      form attached hereto as Exhibit
      A
      (the
“New
      Notes”)
      and
      for the other agreements and mutual covenants contained herein; and

    


    WHEREAS,
      in accordance with the relevant provisions of the Note Purchase Documents and
      the Preferred Purchase Agreement, the Company and the Purchasers desire to
      amend
      the Note Purchase Documents as set forth herein.

    


    NOW
      THEREFORE, in consideration of the mutual covenants contained herein, and for
      good and valuable consideration, the receipt and sufficiency of which is hereby
      acknowledged, the Company and each of the Purchasers agree as follows:


     

    
      
         

      

      
         

        
          

        

      

      
         

      

    

    


    1.
      Issuance
      of New Notes.
      

     

    a)
      New
      Notes.
      On the
      date hereof, the Company shall issue to each of the Purchasers a New Note in
      the
      principal amount set forth opposite such Purchaser’s
      name on
Schedule
      A under
      the
      column entitled “Aggregate Principal Amount,” and each of the Purchasers shall
      pay by wire transfer of immediately available funds to an account designated
      by
      the Company an amount set forth opposite such Purchaser’s
      name on
Schedule
      A under
      the
      column entitled “Additional Purchase Price.” The New Notes shall become
      effective only upon the surrender of the corresponding Prior Notes for
      cancellation by the Company or execution of an affidavit of lost note in form
      and substance reasonably satisfactory to the Company.

     

    b) Representations
      and Warranties.
      Each
      Purchaser hereby confirms that the representations and warranties set forth
      in
      Section 3 of the Note Purchase Agreement are true and correct as of the date
      hereof as if made on the date hereof. Likewise, the Company hereby confirms
      that
      the representations and warranties set forth in Section 4 of the Note Purchase
      Agreement are true and correct as of the date hereof as if made on the date
      hereof.

     

    c) Security
      Agreements.
      The
      Company acknowledges and agrees that any references to Notes in that certain
      Security & Guaranty Agreement, dated January 11, 2007, and that certain
      Intellectual Property Security Agreement, dated January 11, 2007 (together
      the
“Security
      Agreements”),
      shall
      be deemed to include the New Notes and that the performance and observance
      of
      the obligations set forth in the New Notes by the Company shall be deemed to
      be
“Obligations” for purposes of the Security Agreements.

     

    d)
      Closing
      Conditions.
      Each
      Purchaser’s obligation to purchase its New Note is subject to the following
      conditions: 

     

    
      	
            	i.	
              The
                Company’s representations and warranties contained in Section 4 of the
                Note Purchase Agreement shall be true and correct on and as of date
                hereof.

            


    

     

    
      	
            	ii.	
              The
                Company shall deliver a certificate of the Secretary of the Company
                dated
                the date hereof, certifying the incumbency and authority of the officers
                or authorized signatories of the Company who execute the New Note
                and the
                truth, correctness and completeness of the resolutions duly adopted
                by the
                Board of Directors of the Company authorizing the execution of this
                Amendment and the New Notes and the other documents delivered or
                to be
                delivered in connection herewith and the consummation of the transactions
                contemplated herein and therein, as applicable;
                and

            


    

     

    
      	
            	iii.	
              The
                Company shall deliver the opinion of Mintz,
                Levin, Cohn, Ferris, Glovsky and Popeo, P.C.,
                counsel to the Company, dated the date hereof, in substantially the
                same
                form provided at the initial Closing under the Note Purchase Agreement,
                subject only to such changes, qualifications, limitations or exceptions
                as
                may be acceptable to each Lender.

            


    

     

    
      
         

      

      
        2

        
          

        

      

      
         

      

    

     

    e) Additional
      Purchaser.
      Baker
      Bros. Investments II, L.P. shall be deemed to be a “Purchaser” under the Note
      Purchase Agreement and hereunder. 

     

    2.
      Amendments
      to Note Purchase Agreement.
      

     

    a) Preferred
      Financing.
      Section
      5(l) of the Note Purchase Agreement is hereby deleted in its entirety and
      replaced with the following:

     

    “(l) Preferred
      Financing.
      As
      promptly as practical after the Closing Date, and in no event later than April
      15, 2007, each of the Company and the Lenders shall use their respective
      commercially reasonable efforts to negotiate and enter into definitive
      transaction documents pertaining to the transactions (the “Preferred
      Financing”)
      contemplated in that certain Memorandum of Proposed Terms for Private Placement
      of Preferred Stock and Warrants dated as of January 4, 2007 (the “Term
      Sheet”);
      subject in the case of the Lenders to the satisfactory completion of their
      due
      diligence review in their sole discretion. Without limiting the generality
      of
      the foregoing, the Company shall provide each stockholder entitled to vote
      at a
      special or annual meeting of stockholders of the Company (the “Stockholder
      Meeting”),
      which
      shall be promptly called and held not later than July 31, 2007 (the
“Stockholder
      Meeting Deadline”),
      a
      proxy statement, in a form reviewed and approved by the Lenders soliciting
      each
      such stockholder’s affirmative vote at the Stockholder Meeting for approval of
      the Preferred Financing and the other matters contemplated in the Term Sheet
      in
      accordance with applicable law and the rules and regulations of the American
      Stock Exchange (such affirmative approval being referred to herein as the
“Stockholder
      Approval”),
      and
      the Company shall use its commercially reasonable efforts to solicit its
      stockholders’ approval of such resolutions and to cause the Board of Directors
      of the Company to recommend to the stockholders that they approve such
      resolutions. The Company shall use its commercially reasonable efforts to obtain
      the Stockholder Approval by the Stockholder Meeting Deadline.”

     

    b) Fees
      and Expenses.
      The
      Company’s obligation to reimburse the Collateral Agent or
      its
      designee(s) for fees and expenses in Section 15 of the Note Purchase Agreement
      is hereby amended from a maximum of “One Hundred Thousand Dollars ($100,000)” to
“One Hundred Seventy-Five Thousand Dollars ($175,000).”

     

    3. Amendment
      to Warrants.
      The
      definition of Initial Exercise Date as set forth in the first paragraph of
      each
      of the Warrants is hereby amended from “May 31, 2007” to read “July 31,
      2007”.

     

    4. Exclusivity.
      The
      Company and Purchasers 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 “July
      31, 2007.” 

     

    
      
         

      

      
        3

        
          

        

      

      
         

      

    

     

    5. Ratification.
      The
      parties hereby ratify and confirm in all respects the Note Purchase Documents
      and the Preferred Purchase Agreement, as amended by this Amendment.

     

    6. Governing
      Law.
      All
      questions concerning the construction, validity, enforcement and interpretation
      of the Transaction Documents shall be governed by and construed and enforced
      in
      accordance with the internal laws of the State of New York, without regard
      to
      the principles of conflicts of law thereof. 

     

    7. Other
      Matters.
      The
      Company hereby acknowledges and agrees that the execution and delivery by the
      Purchasers of this Amendment shall not be deemed to create a course of dealing
      or otherwise obligate the Purchasers to execute similar extensions, amendments
      or waivers under the same or similar circumstances in the future.

     

    8. Execution.
      This
      Agreement may be executed in two or more counterparts, all of which when taken
      together shall be considered one and the same agreement and shall become
      effective when counterparts have been signed by each party and delivered to
      the
      other party, it being understood that both parties need not sign the same
      counterpart. In the event that any signature is delivered by facsimile
      transmission or by e-mail delivery of a “.pdf” format data file, such signature
      shall create a valid and binding obligation of the party executing (or on whose
      behalf such signature is executed) with the same force and effect as if such
      facsimile or “.pdf” signature page were an original thereof.

    


     

    [remainder
      left intentionally blank]

     

    
      
         

      

      
        4

        
          

        

      

      
         

      

    


    IN
      WITNESS WHEREOF, the undersigned hereby executes this Omnibus Amendment as
      of
      the date first set forth above.

    


    
      	
              ALTEON
                INC.

            	
              Address
                for Notice:

            
	 	 
	
              By: 
                /s/
                Noah Berkowitz

              
                

              

              Name:
                Noah Berkowitz

              Title:
                President

            	
              221
                West Grand Avenue

              Montvale,
                NJ 07645

            
	 	 
	
              With
                a copy to (which shall not constitute notice):

               

              Mintz
                Levin Cohn Ferris Glovsky and Popeo, P.C.

              One
                Financial Center

              Boston,
                MA 02110

              Attn:
                William T. Whelan, Esq.

            	 


    

    


    


    [REMAINDER
      OF PAGE INTENTIONALLY LEFT BLANK

    SIGNATURE
      PAGE FOR PURCHASERS FOLLOW]

     

    
      
         

      

      
         

        
          

        

      

      
         

      

    


    IN
      WITNESS WHEREOF, the undersigned hereby executes this Omnibus Amendment as
      of
      the date first set forth above. 

    


    
      	
              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

              
                

              

              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

              
                

              

              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 

              its
                general partner

               

              By: 
                /s/
                Felix Baker

              
                

              

              Name:
                Felix Baker, Ph.D.

              Title:
                Managing Member

               

              14159,
                L.P.

              By: 
                14159
                Capital, L.P., its general partner

              By: 
                14159
                Capital (GP), LLC, its general partner

               

              By: 
                /s/
                Felix Baker

              
                

              

              Name:
                Felix Baker, Ph.D.

              Title:
                Managing Member

               

              BAKER
                BROS. INVESTMENTS II, L.P.

              By: 
                Baker
                Bros. Capital, L.P., 

              its
                general partner

              By: 
                Baker
                Bros. Capital (GP), LLC, 

              its
                general partner

               

              By: 
                /s/
                Felix Baker

              
                

              

              Name:
                Felix Baker, Ph.D.

              Title:
                Managing Member

            	
              Address
                for Notice:

              667
                Madison Avenue

              17th
                Floor

              New
                York, NY 10021

            


    

     

    
      
         

      

      
         

        
          

        

      

      
         

      

    

     

    SCHEDULE
      A

     

    LENDERS

    


     

    
      	
              Lender
                Name and Address

            	
              Amount
                of Prior Notes

            	
              Additional
                Purchase Price

            	
              Amount
                of New Notes

              (Combined
                Principal Balance)

            
	
               

              Baker
                Tisch Investments, L.P. 
667 Madison Avenue, 17th Floor 
New York,
                NY 10021 

            	
              $20,781.11

            	
              --

            	
               

               

              $20,781.11

            
	
               

              Baker
                Tisch Investments, L.P. 
667 Madison Avenue, 17th Floor 
New York,
                NY 10021 

            	
              $19,177.40

            	
              --

            	
               

               

              $19,177.40

            
	
               

              Baker
                Biotech Fund I, L.P. 

              667
                Madison Avenue, 17th Floor 
New York, NY 10021 

            	
              $402,372.05

            	
              $446,428.00

            	
               

               

              $848,800.05

            
	
               

              Baker
                Biotech Fund I, L.P. 

              667
                Madison Avenue, 17th Floor 
New York, NY 10021 

            	
              $359,715.41

            	
              $358,316.00

            	
               

               

              $718,031.41

            
	
               

              Baker
                Brothers Life Sciences, L.P. 
667 Madison Avenue, 17th Floor 
New
                York, NY 10021 

            	
              $2,128,162.10

            	
              $2,122,374.00

            	
               

               

              $4,250536.10

            
	
               

              14159,
                L.P. 

              667
                Madison Avenue, 17th Floor 
New York, NY 10021 

            	
              $69,791.94

            	
              $67,474.00

            	
               

               

              $137,265.94

            
	
               

              Baker
                Bros. Investments II, L.P.

              667
                Madison Avenue, 17th Floor 
New York, NY 10021 

            	
              --

            	
              $5,408.00

            	
               

               

              $5,408.00

            
	
              Total:

            	
               

              $
                3,000,000.01

            	
               

              $
                3,000,000.00

            	
               

              $
                6,000,000.01

            


    

    


    
      
         

      

      
         

        
          

        

      

      
         

      

    


    EXHIBIT
      A

     

    FORM
      OF NEW NOTE

     

    THIS
      NOTE
      HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE
“ACT”), OR APPLICABLE STATE SECURITIES LAWS. IT MAY NOT BE SOLD, OFFERED FOR
      SALE, PLEDGED OR HYPOTHECATED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION
      STATEMENT UNDER THE ACT AND APPLICABLE STATE SECURITIES LAWS OR EVIDENCE
      REASONABLY SATISFACTORY TO THE BORROWER THAT SUCH REGISTRATION IS NOT REQUIRED.
      THE SECURITIES ISSUED UPON SUCH CONVERSION MAY NOT BE SOLD, OFFERED FOR SALE,
      PLEDGED, OR HYPOTHECATED IN THE ABSENCE OF AN EFFECTIVE REGISTRATION STATEMENT
      UNDER THE ACT OR APPLICABLE STATE SECURITIES LAWS OR EVIDENCE REASONABLY
      SATISFACTORY TO THE BORROWER THAT SUCH REGISTRATION IS NOT
      REQUIRED.

    


    AMENDED
      AND RESTATED

    SENIOR
      CONVERTIBLE SECURED PROMISSORY NOTE

    


    
      	 	 	Parsippany, New Jersey 	 
	$__________ 	 	June __, 2007 	 


    

    


    FOR
      VALUE
      RECEIVED, Alteon Inc., a Delaware corporation (the “Borrower”),
      located at 6 Campus Drive, Parsippany, NJ 07054, hereby promises to pay to
      _______________________ (the “Lender”),
      located at ____________________________________________, or at such other place
      as the Lender may from time to time reasonably designate, the principal sum
      of
      ______________________ ($___________)1 
      (the
“Principal
      Amount”)
      in
      lawful money of the United States, in immediately available funds, ON DEMAND,
      on
      or after July 31, 2007 (the “Maturity
      Date”),
      together with any additional amounts as may be required to be paid under Section
      11 of this Note, unless the Principal Amount is earlier converted as set forth
      herein. 

     

    1. This
      Note
      amends and restates in its entirety that certain Senior Convertible Secured
      Promissory Note issued by the Borrower to the Lender, effective January 11,
      2007
      (the “Prior
      Note”),
      in
      the principal amount of ______________________ ($___________)2 
      (the
“Prior
      Principal”).
      The
      Prior Note is amended and restated hereby to increase the principal amount
      thereunder by an additional amount equal to the Prior Principal (“Additional
      Principal”)
      and to
      effect certain other changes. This Note shall become effective only upon the
      surrender of the Prior Note by the Lender for cancellation by the Borrower
      or
      execution of an affidavit of lost note in form and substance reasonably
      satisfactory to the Borrower.

     

    ___________________________

    
      
        1
          Insert
          appropriate percentage of $6 million.

      

      
        2
          Insert
          appropriate percentage of $3 million.

      

    

     

    
      
         

      

      
         

        
          

        

      

      
         

      

    

     

    2. Interest
      shall accrue at a rate per annum equal to eight percent (8%) with respect to
      (a)
      the Prior Principal, from the date of January 11, 2007 until maturity (whether
      by demand on or after the Maturity Date or by acceleration), and (b) the
      Additional Principal, from the date hereof until maturity (whether by demand
      on
      or after the Maturity Date or by acceleration). Such interest shall be payable
      at maturity or upon conversion. In no event shall the rate of interest hereunder
      exceed the maximum interest rate permitted by applicable law. 

     

    3. This
      Note
      is one of several notes (the “Notes”)
      in the
      aggregate principal amount of up to $6,000,000 and of like tenor issued by
      the
      Borrower to the Lender and others (together, the “Lenders”)
      pursuant to the terms of that certain Convertible Note and Warrant Purchase
      Agreement, dated January 11, 2007, as amended (the “Bridge
      Loan Agreement”).
      By
      acceptance of this Note, the Lender hereby agrees that each of the Notes issued
      pursuant to the Bridge Loan Agreement shall rank equally and ratably without
      priority over one another, and the Borrower agrees that, except as expressly
      provided by the terms of the Notes, none of the Notes shall be paid, in whole
      or
      in part, unless an equivalent, pro rata payment is made with respect to all
      other Notes.

     

    4. As
      security for the payment, performance and observance of the obligations set
      forth in the Prior Note, the Borrower has previously granted a security interest
      in its assets to the collateral agent named in, and pursuant to, that certain
      Security & Guaranty Agreement, dated January 11, 2007 (the “Security
      Agreement”)
      and
      that certain Intellectual Property Security Agreement, dated January 11, 2007
      (the “IP Security
      Agreement”
and
      together with the Security Agreement, the “Security
      Agreements”).
      Borrower hereby acknowledges and agrees that any reference to Notes in the
      Security Agreements shall be deemed to include this Note and that the
      performance and observance of the obligations set forth in this Note by the
      Borrower shall be deemed to be “Obligations” for purposes of the Security
      Agreements.

     

    5.
       If
      this
      Note has not previously been converted, the Borrower may repay the principal
      balance of this Note plus accrued but unpaid interest, together with any
      additional amounts as may be required to be paid under Section 11 of this Note,
      without penalty, at any time prior to the Maturity Date.

     

    6. In
      the
      event that any principal or accrued interest on this Note remains outstanding
      at
      such time as the Borrower consummates a Preferred Financing (as defined below),
      the entire principal balance then outstanding plus accrued but unpaid interest
      shall automatically be converted into the securities of the Borrower issued
      in a
      Preferred Financing at a conversion rate equal to the price per security at
      which the securities are issued in a Preferred Financing and with the same
      terms
      and conditions as such securities (hereinafter, an “Automatic
      Conversion”).
      The
      Automatic Conversion will be effective upon the consummation of a Preferred
      Financing, and the Borrower shall be relieved of any continued obligation to
      repay the principal or unpaid interest on this Note thereafter. The Borrower
      shall promptly deliver to the Lender written notification of the consummation
      of
      a Preferred Financing, and the Lender shall deliver the original of this Note
      to
      the Borrower for cancellation. The Borrower shall have no obligation to deliver
      securities issuable upon a Preferred Financing until such time as it receives
      the original of this Note or an affidavit of lost security from the Lender.
      

     

    For
      purposes of this Note, “Preferred
      Financing”
shall
      mean that certain contemplated transaction or series of transactions prior
      to
      the Maturity Date in which the Borrower sells shares of its preferred capital
      stock and warrants to purchase preferred stock to the Lenders and other
      investors as the Lenders may approve, in an amount up to $25,000,000, as more
      particularly described in that certain Series B Preferred Stock and Warrant
      Purchase Agreement dated as of April 5, 2007 by and among the Borrower, the
      Lenders and certain other parties.

     

    
      
         

      

      
         

        
          

        

      

      
         

      

    

     

    7. In
      the
      event that any principal or accrued interest on this Note remains outstanding
      at
      such time as Borrower consummates an Equity Financing (as defined below), the
      principal balance then outstanding plus accrued but unpaid interest may be
      converted, in whole or in part, at the election of the Lender, into the
      securities of the Borrower issued in the Equity Financing at a conversion rate
      equal to the price per security at which the securities are issued in the Equity
      Financing (hereinafter, a “Voluntary
      Conversion”).
      The
      Borrower shall promptly deliver to the Lender written notification of the
      consummation of an Equity Financing, and the Lender shall have ten (10) business
      days from the date of such notice to elect, by written notice to the Borrower,
      to convert the Note. In the event the Lender elects to convert the Note into
      securities issued in the Equity Financing, the Lender shall deliver the original
      of this Note to the Borrower for cancellation together with the election notice.
      The Borrower shall have no obligation to deliver securities issuable upon a
      Voluntary Conversion until such time as it receives the original of this Note
      or
      an affidavit of lost security from the Lender. If this Note is converted in
      part, the Borrower shall reissue a Note in substantially the same form to the
      Lender reflecting the remaining principal balance.

     

    For
      purposes of this Note, “Equity
      Financing”
shall
      mean a transaction or series of transactions in which the Borrower sells its
      securities which occurs after the date hereof and prior to the Maturity Date
      and
      which does not constitute a Preferred Financing. 

     

    8. In
      the
      event that any principal or accrued interest on this Note remains outstanding
      prior to the Maturity Date and no Automatic Conversion or Voluntary Conversion
      has taken place, the principal balance then outstanding plus accrued but unpaid
      interest may be converted, in whole or in part, at the election of the Lender,
      into shares of the Borrower’s common stock, $0.01 per value per share
      (“Common
      Stock”),
      at a
      conversion rate equal to the closing price on the American Stock Exchange or
      the
      Nasdaq Stock Market (as reported by Bloomberg L.P. at 4:15 PM New York time))
      of
      a share of the Borrower’s Common Stock on the date hereof (hereinafter, a
“Voluntary
      Common Stock Conversion”).
      Upon
      election to consummate a Voluntary Common Stock Conversion, the Lender shall
      promptly deliver to the Borrower written notification of such election. The
      Lender shall also deliver the original of this Note to the Borrower for
      cancellation together with the election notice. The Borrower shall have no
      obligation to deliver securities issuable upon a Voluntary Common Stock
      Conversion until such time as it receives the original of this Note or an
      affidavit of lost security from the Lender. If this Note is converted in part,
      the Borrower shall reissue a Note in substantially the same form to the Lender
      reflecting the remaining principal balance.

     

    9. No
      fractional shares of capital stock of the Borrower shall be issued upon
      conversion of this Note. In lieu of any fractional shares to which the holder
      would otherwise be entitled, the Borrower shall pay cash equal to such fraction
      multiplied by the applicable conversion price.

     

    
      
         

      

      
         

        
          

        

      

      
         

      

    

     

    10. Unless
      and until conversion of this Note as aforesaid, the Lender shall not by virtue
      of this Note have or exercise any rights by virtue hereof as a stockholder
      of
      the Borrower.

     

    11. If
      no
      Preferred Financing is consummated on or prior to the Maturity Date, and the
      Lender has not elected a Voluntary Conversion or Voluntary Common Stock
      Conversion, then (i) the entire principal amount of this Note, together with
      all
      accrued but unpaid interest, shall, at the election of the Lender, ON DEMAND,
      be
      due and payable on or after such date, (ii) the Borrower shall pay the Lender
      an
      additional sum of [_______________] ($___________)3 
      and
      (iii) the Borrower agrees to pay the Lender an amount equal to thirty percent
      (30%) of the Gross Proceeds (defined below) to the Borrower of all Financing
      Transactions (defined below), Sale Transactions (defined below) and Product
      Candidate Transactions (defined below) completed by the Borrower on or before
      June 30, 2009, subject to a maximum additional payment under this Section
      11(iii) of [_______________] ($___________)4 .
      “Gross
      Proceeds”
shall
      mean (a) in the case of a Financing Transaction the amount paid by the
      purchasers of the securities in the transaction, irrespective of underwriting
      discounts, private placement commissions or other fees; (b) in the case of
      a
      Sale Transaction the sum of (i) the aggregate fair market value of any
      securities issued and any other non-cash consideration delivered (including,
      without limitation, any joint venture or other revenue interest delivered to,
      or
      retained by, the Borrower), and any cash consideration paid to the Borrower
      or
      its security holders (including, without limitation, holders of options,
      warrants, convertible securities and preferred securities) in connection with
      the Sale Transaction, and (ii) the amount of all indebtedness and preferred
      stock of the Borrower or any subsidiary thereof, which is assumed or acquired
      by
      the purchaser or retired or defeased in connection with the Sale Transaction;
      and (c) in the case of a Product Candidate Transaction the aggregate fair market
      value of any securities issued and any other non-cash consideration delivered
      (including, without limitation, any joint venture interest delivered to, or
      retained by, the Borrower), and any cash consideration paid to the Borrower
      in
      connection with the Product Candidate Transaction. “Financing
      Transaction”
shall
      mean any equity financing by or on behalf of the Borrower or its subsidiaries,
      including, but not limited to, any sale of common stock, preferred stock,
      warrants, convertible debt or other equity linked security. “Sale
      Transaction”
shall
      mean any transaction or series of transactions in which one or more persons
      or
      entities acquires directly or indirectly a majority of the stock or all or
      substantially all of the assets, revenues, income or business of the Borrower
      or
      any subsidiary or otherwise gains control of the Borrower or any subsidiary,
      including any combination of the businesses regardless of the structure or
      form
      of the transaction. “Product
      Candidate Transaction” shall
      mean any licensing, development, commercialization, distribution, marketing,
      co-marketing, collaboration, partnering, sale, divestiture or similar agreement
      relating to the transfer of intellectual property or other rights or assets
      relating to the Borrower’s current or future product candidates.

     

    
      ______________________________________

      3
        Insert
        appropriate percentage of $6 million.

      
        4
          Insert
          appropriate percentage of $8 million.

         

        
          
             

          

          
             

            
              

            

          

          
             

          

        

      

    

     

    12. If
      (a)
      the Borrower fails to make any payment under this Note; (b) the Borrower
      breaches any representation, warranty, covenant or agreement in the Bridge
      Loan
      Agreement or any other Transaction Document (as defined in the Bridge Loan
      Agreement); (c) the Borrower agrees, consents or acquiesces to any amendment,
      supplement or other modification to, or termination of, any of any Material
      License Agreement or otherwise breaches any representation, warranty, covenant
      or agreement in any Material License Agreement that would give the other party
      thereto the right to terminate such Material License Agreement, or takes any
      other action or fails to take any action that may result in the early
      termination of a Material License Agreement; (d) the Borrower fails to pay
      when
      due any Indebtedness (as defined in the Bridge Loan Agreement) of the Borrower
      in an aggregate amount of Five Hundred Thousand Dollars ($500,000) or greater
      at
      any one time; (e) a final judgment or judgments for the payment of money
      aggregating in excess of Five Hundred Thousand Dollars ($500,000) are rendered
      against the Borrower and which judgments are not, within sixty (60) days after
      the entry thereof, bonded, discharged or stayed pending appeal, or are not
      discharged within sixty (60) days after the expiration of such stay; (f) the
      Borrower shall be dissolved, become insolvent (however defined or evidenced),
      make an assignment for the benefit of creditors or make or send a notice of
      intended bulk transfer; (g) any petition or proceeding for any relief under
      any
      bankruptcy, reorganization, arrangement, insolvency, readjustment of debt,
      receivership, liquidation or dissolution law or statute now or hereinafter
      in
      effect (whether at law or in equity) is filed or commenced by the Borrower;
      or
      (h) any trustee or receiver is appointed for the Borrower or any property of
      the
      Borrower, a meeting of creditors is convened or a committee of creditors is
      appointed for, or any petition or proceeding for any relief under any
      bankruptcy, reorganization, arrangement, insolvency, readjustment of debt,
      receivership, liquidation or dissolution law or statute now or hereinafter
      in
      effect (whether at law or in equity) is filed or commenced against the Borrower,
      which proceeding is not dismissed within one hundred twenty (120) days (each
      of
      the foregoing, an “Event
      of Default”),
      then
      and in any such event and at any time thereafter, the Lender may, at its option,
      declare all amounts owing under Section 11 of this Note to be due and payable,
      whereupon the maturity of the unpaid balance hereof shall be accelerated and
      the
      principal, together with all unpaid interest accrued thereon, shall forthwith
      become due and payable; provided,
      that,
      if any petition or proceeding for any relief under any bankruptcy,
      reorganization, arrangement, insolvency, readjustment or debt, receivership,
      liquidation or dissolution law or statute now or hereinafter in effect (whether
      at law or in equity) is filed or commenced by the Borrower, all amounts owing
      under this Note shall be, without notice, declaration or any action by the
      Lender, accelerated, and immediately due and payable. 

     

    13. The
      Borrower hereby waives diligence, demand, presentment, protest and notice of
      any
      kind, and assents to extensions of time of payment, release, surrender or
      substitution or security, or forbearance or other indulgence, without
      notice.

     

    14. No
      act,
      omission or delay by the Lender or course of dealing between the Lender and
      the
      Borrower shall constitute a waiver of the rights and remedies of the Lender
      hereunder. No single or partial waiver by the Lender of any Event of Default
      or
      right or remedy which it may have shall operate as a waiver of any other Event
      of Default, right or remedy or of the same Event of Default, right or remedy
      on
      a future occasion.

     

    15. Unless
      otherwise provided herein or in the Bridge Loan Agreement, any notice or other
      communication herein required or permitted to be given shall be in writing
      and
      may be personally served, telecopied, telexed or sent by United States mail,
      to
      Borrower or Lender, as the case may be, addressed to it at the respective
      address set forth on the first page of this Note and in the Bridge Loan
      Agreement, or at such other address as shall be designated by Borrower or
      Lender, as the case may be, in a written notice to the other party complying
      as
      to delivery with the terms of this Section 15. All such notices and other
      communications shall be deemed to have been given when (i) delivered by hand,
      (ii) sent
      by
      overnight courier, with receipt acknowledgment, or (iii) sent by certified
      mail, return receipt requested, postage prepaid.

     

    
      
         

      

      
         

        
          

        

      

      
         

      

    

     

    16. This
      Note
      shall be governed by and construed in accordance with the internal law of the
      State of New York (without giving effect to the conflict of laws principles
      thereof). Any legal action or proceeding with respect to this Note shall be
      brought in the courts of the State of New York or of the United States of
      America for the Southern District of New York, and, by execution and delivery
      of
      this Note, the Borrower hereby accepts for itself and in respect of its
      property, generally and unconditionally, the jurisdiction of the aforesaid
      courts. 

     

    17. No
      provision hereof shall be modified, altered or limited except by a written
      instrument expressly executed by the Borrower and Lenders holding a majority
      in
      principal amount of the then outstanding Notes.

     

    18. In
      the
      event that any court of competent jurisdiction shall determine that any
      provision, or any portion thereof, contained in this Note shall be unreasonable
      or unenforceable in any respect, then such provision shall be deemed limited
      to
      the extent that such court deems it reasonable and enforceable, and as so
      limited shall remain in full force and effect. In the event that such court
      shall deem any such provision, or portion thereof, wholly unenforceable, the
      remaining provisions of this Note shall nevertheless remain in full force and
      effect.

     

    19. This
      Note
      and all obligations evidenced hereby shall be binding upon the heirs, executors,
      administrators, successors and assigns of the Borrower and shall, together
      with
      the rights and remedies of the Lender hereunder, inure to the benefit of the
      Lender, its successors, endorsees and permitted assigns.

    


     

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    In
      witness whereof, the Borrower has caused this Note to be executed by its duly
      elected officer as of the date first set forth above.

     

    
      	 	 	 
	 	ALTEON
              INC.
	 
 	 
 	 
 
	 	By:  	 
	 	
              
Noah
              Berkowitz
	 	President
              and
              Chief Executive Officer