Exhibit
      10.4

     

    REGISTRATION
      RIGHTS AGREEMENT

     

    This
      Registration Rights Agreement (this “Agreement”)
      is
      made and entered into as of January 11, 2007, among Alteon Inc., a Delaware
      corporation (the “Company”),
      and
      the several purchasers signatory hereto (each such purchaser is a “Purchaser”
and
      collectively, the “Purchasers”).

     

    This
      Agreement is made pursuant to the Note and Warrant Purchase Agreement, dated
      as
      of January 11, 2007 between the Company and each Purchaser (the “Purchase
      Agreement”).

     

    The
      Company and each Purchaser hereby agrees as follows:

     

    1. Definitions.
      Capitalized terms used and not otherwise defined herein that are defined in
      the
      Purchase Agreement shall have the meanings given such terms in the Purchase
      Agreement. As used in this Agreement, the following terms shall have the
      following meanings:

     

    “Advice”
shall
      have the meaning set forth in Section 6(d).

     

    “Effective
      Date”
shall
      mean the date that the initial Registration Statement filed by the Company
      pursuant to this Agreement is declare effective by the SEC.

     

    “Effectiveness
      Date”
means,
      with respect to the initial Registration Statement required to be filed
      hereunder, the 90th calendar day following the Negotiation Deadline (the 120th
      calendar day in the case of a “full review” by the Commission) if the initial
      Registration Statement is on Form S-3 or the 270th
      calendar
      day following the Negotiation Deadline if the initial Registration Statement
      is
      on Form S-1 and, with respect to any additional Registration Statements which
      may be required pursuant to Section 3(c), the 90th calendar day following the
      date on which the Company first knows, or reasonably should have known, that
      such additional Registration Statement on Form S-3 is required hereunder (the
      270th calendar day if such Registration Statement is on Form S-1); provided,
      however,
      in the
      event the Company is notified by the Commission that one of the above
      Registration Statements will not be reviewed or is no longer subject to further
      review and comments, the Effectiveness Date as to such Registration Statement
      shall be the fifth Trading Day following the date on which the Company is so
      notified if such date precedes the dates required above

     

    “Effectiveness
      Period”
shall
      have the meaning set forth in Section 2(a).

     

    “Event”
shall
      have the meaning set forth in Section 2(b).

     

    “Event
      Date”
shall
      have the meaning set forth in Section 2(b).

     

    
      
        
        

      

      
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    “Filing
      Date”
means,
      with respect to the initial Registration Statement required hereunder, the
      30th
      calendar
      day following the Negotiation Deadline and, with respect to any additional
      Registration Statements which may be required pursuant to Section 3(c), the
      30th
      day
      following the date on which the Company first knows, or reasonably should have
      known that such additional Registration Statement is required
      hereunder.

     

    “Holder”
or
      “Holders”
means
      the holder or holders, as the case may be, from time to time of Registrable
      Securities.

     

    “Indemnified
      Party”
shall
      have the meaning set forth in Section 5(c).

     

    “Indemnifying
      Party”
shall
      have the meaning set forth in Section 5(c).

     

    “Losses”
shall
      have the meaning set forth in Section 5(a).

     

    “Negotiation
      Deadline”
shall
      mean March 31, 2007, or such later date as is mutually agreed to in writing
      by
      the parties.

     

    “Plan
      of Distribution”
shall
      have the meaning set forth in Section 2(a). 

     

    “Prospectus”
means
      the prospectus included in a Registration Statement (including, without
      limitation, a prospectus that includes any information previously omitted from
      a
      prospectus filed as part of an effective registration statement in reliance
      upon
      Rule 430A promulgated under the Securities Act), as amended or supplemented
      by
      any prospectus supplement, with respect to the terms of the offering of any
      portion of the Registrable Securities covered by a Registration Statement,
      and
      all other amendments and supplements to the Prospectus, including post-effective
      amendments, and all material incorporated by reference or deemed to be
      incorporated by reference in such Prospectus.

     

    “Registrable
      Securities”
means
      all of the Common Stock issuable pursuant to the exercise of the Warrants and
      conversion of the Convertible Notes sold pursuant to the Purchase Agreement
      and
      any shares of Common Stock issued or issuable upon any stock split, dividend
      or
      other distribution, recapitalization or similar event with thereto.


     

    “Registration
      Statement”
means
      the registration statements required to be filed hereunder and any additional
      registration statements contemplated by Section 3(c), including (in each case)
      the Prospectus, amendments and supplements to such registration statement or
      Prospectus, including pre- and post-effective amendments, all exhibits thereto,
      and all material incorporated by reference or deemed to be incorporated by
      reference in such registration statement.

     

    “Rule
      415”
means
      Rule 415 promulgated by the Commission pursuant to the Securities Act, as such
      Rule may be amended from time to time, or any similar rule or regulation
      hereafter adopted by the Commission having substantially the same purpose and
      effect as such Rule.

     

    “Rule
      424”
means
      Rule 424 promulgated by the Commission pursuant to the Securities Act, as such
      Rule may be amended from time to time, or any similar rule or regulation
      hereafter adopted by the Commission having substantially the same purpose and
      effect as such Rule.

     

    
      
        
        

      

      
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    “Selling
      Shareholder Questionnaire”
shall
      have the meaning set forth in Section 3(a).

     

    “Trading
      Day”
shall
      mean a day on which the Common Stock of the Company is traded on the American
      Stock Exchange, the Nasdaq Stock Market or the New York Stock
      Exchange.

     

    2. Shelf
      Registration.

     

    (a) On
      or
      prior to each Filing Date, the Company shall prepare and file with the
      Commission a “Shelf” Registration Statement covering the resale of one hundred
      percent (100%) of the Registrable Securities on such Filing Date for an offering
      to be made on a continuous basis pursuant to Rule 415. The Registration
      Statement shall be on Form S-3 (except if the Company is not then eligible
      to
      register for resale the Registrable Securities on Form S-3, in which case such
      registration shall be on another appropriate form in accordance herewith) and
      shall contain (unless otherwise directed by at least an 85% majority in interest
      of the Holders) substantially the “Plan
      of Distribution”
      attached hereto as Annex
      A.
      Subject
      to the terms of this Agreement, the Company shall use its good faith
      commercially reasonable efforts to cause a Registration Statement to be declared
      effective under the Securities Act as promptly as possible after the filing
      thereof, but in any event prior to the applicable Effectiveness Date, and shall
      use its good faith commercially reasonable efforts to keep such Registration
      Statement continuously effective under the Securities Act until all Registrable
      Securities covered by such Registration Statement have been sold, or may be
      sold
      without volume restrictions pursuant to Rule 144(k), as determined by the
      counsel to the Company pursuant to a written opinion letter to such effect,
      addressed and acceptable to the Company’s transfer agent and the affected
      Holders (the “Effectiveness
      Period”).
      The
      Company shall telephonically request effectiveness of a Registration Statement
      as of 5:00 pm Eastern Time on a Trading Day. The Company shall immediately
      notify the Holders via facsimile or electronic transmission of the effectiveness
      of a Registration Statement on the same Trading Day that the Company
      telephonically confirms effectiveness with the Commission, which shall be the
      date requested for effectiveness of a Registration Statement. The Company shall,
      by 9:30 am Eastern Time on the Trading Day after the Effective Date, file a
      final Prospectus with the Commission as required by Rule 424. Failure to so
      notify the Holder within one (1) Trading Day of such notification or
      effectiveness or failure to file a final Prospectus as aforesaid shall be deemed
      an Event under Section 2(b).

     

    
      
        
        

      

      
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    (b) If:
      (i) a
      Registration Statement is not filed on or prior to its Filing Date (if the
      Company files a Registration Statement without affording the Holders the
      opportunity to review and comment on the same as required by Section 3(a),
      the
      Company shall not be deemed to have satisfied this clause (i)), or (ii) the
      Company fails to file with the Commission a request for acceleration in
      accordance with Rule 461 promulgated under the Securities Act, within five
      Trading Days of the date that the Company is notified (orally or in writing,
      whichever is earlier) by the Commission that a Registration Statement will
      not
      be “reviewed,” or not subject to further review, or (iii) prior to its
      Effectiveness Date, the Company fails to file a pre-effective amendment and
      otherwise respond in writing to comments made by the Commission in respect
      of
      such Registration Statement within 15 calendar days after the receipt of
      comments by or notice from the Commission that such amendment is required in
      order for a Registration Statement to be declared effective, or (iv) a
      Registration Statement filed or required to be filed hereunder is not declared
      effective by the Commission by its Effectiveness Date, or (v) after the
      Effectiveness Date, a Registration Statement ceases for any reason to remain
      continuously effective as to all Registrable Securities for which it is required
      to be effective, or the Holders are otherwise not permitted to utilize the
      Prospectus therein to resell such Registrable Securities for more than 15
      consecutive calendar days or more than an aggregate of 25 calendar days during
      any 12-month period (which need not be consecutive calendar days) (any such
      failure or breach being referred to as an “Event”,
      and
      for purposes of clause (i) or (iv) the date on which such Event occurs, or
      for
      purposes of clause (ii) the date on which such five Trading Day period is
      exceeded, or for purposes of clause (iii) the date which such 15 calendar day
      period is exceeded, or for purposes of clause (v) the date on which such 15
      or
      25 calendar day period, as applicable, is exceeded being referred to as the
      “Event
      Date”),
      then
      in addition to any other rights the Holders may have hereunder or under
      applicable law, on such Event Date and on each monthly anniversary of such
      Event
      Date (if the applicable Event shall not have been cured by such date) until
      the
      applicable Event is cured, the Company shall pay to each Holder an amount in
      cash, as partial liquidated damages and not as a penalty, equal to 2% of the
      aggregate purchase price paid by such Holder pursuant to the Purchase Agreement
      for any Securities then held by such Holder, subject to an overall limit of
      36%.
      The partial liquidated damages pursuant to the terms hereof shall apply on
      a
      daily pro-rata basis for any portion of a month prior to the cure of an
      Event.

     

    3. Registration
      Procedures

     

    In
      connection with the Company’s registration obligations hereunder, the Company
      shall:

     

    (a) Not
      less
      than five (5) Trading Days prior to the filing of each Registration Statement
      and not less than one (1) Trading Day prior to the filing of any related
      Prospectus or any amendment or supplement thereto (including any document that
      would be incorporated or deemed to be incorporated therein by reference), the
      Company shall, (i) furnish to each Holder copies of all such documents proposed
      to be filed, which documents (other than those incorporated or deemed to be
      incorporated by reference) will be subject to the review of such Holders, and
      (ii) use its good faith commercially reasonable efforts to cause its officers
      and directors, counsel and independent certified public accountants to respond
      to such inquiries as shall be necessary, in the reasonable opinion of respective
      counsel to each Holder to conduct a reasonable investigation within the meaning
      of the Securities Act. The Company shall not file a Registration Statement
      or
      any such Prospectus or any amendments or supplements thereto to which the
      Holders of a majority of the Registrable Securities shall reasonably object
      in
      good faith, provided that, the Company is notified of such objection in writing
      no later than five (5) Trading Days after the Holders have been so furnished
      copies of a Registration Statement or one (1) Trading Day after the Holders
      have
      been so furnished copies of any related Prospectus or amendment or supplement
      thereto. Each Holder agrees to furnish to the Company a completed Questionnaire
      in the form attached to this Agreement as Annex B (a “Selling
      Shareholder Questionnaire”)
      not
      less than two (2) Trading Days prior to the Filing Date or by the end of the
      fourth Trading Day following the date on which such Holder receives draft
      materials in accordance with this Section.

     

    
      
        
        

      

      
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    (b) (i)
      Prepare and file with the Commission such amendments, including post-effective
      amendments, to a Registration Statement and the Prospectus used in connection
      therewith as may be necessary to keep a Registration Statement continuously
      effective as to the applicable Registrable Securities for the Effectiveness
      Period and prepare and file with the Commission such additional Registration
      Statements in order to register for resale under the Securities Act all of
      the
      Registrable Securities; (ii) cause the related Prospectus to be amended or
      supplemented by any required Prospectus supplement (subject to the terms of
      this
      Agreement), and as so supplemented or amended to be filed pursuant to Rule
      424;
      (iii) respond as promptly as reasonably possible to any comments received from
      the Commission with respect to a Registration Statement or any amendment thereto
      and as promptly as reasonably possible provide the Holders true and complete
      copies of all correspondence from and to the Commission relating to a
      Registration Statement (provided that the Company may excise any information
      contained therein which would constitute material non-public information as
      to
      any Holder which has not executed a confidentiality agreement with the Company);
      and (iv) comply in all material respects with the provisions of the Securities
      Act and the Exchange Act with respect to the disposition of all Registrable
      Securities covered by a Registration Statement during the applicable period
      in
      accordance (subject to the terms of this Agreement) with the intended methods
      of
      disposition by the Holders thereof set forth in such Registration Statement
      as
      so amended or in such Prospectus as so supplemented.

     

    (c) If
      during
      the Effectiveness Period, the number of Registrable Securities at any time
      exceeds one hundred percent (100%) of the number of shares of Common Stock
      then
      registered in a Registration Statement, then the Company shall file as soon
      as
      reasonably practicable but in any case prior to the applicable Filing Date,
      an
      additional Registration Statement covering the resale by the Holders of not
      less
      than one hundred percent (100%) of the number of such Registrable
      Securities.

     

    (d) Notify
      the Holders of Registrable Securities to be sold (which notice shall, pursuant
      to clauses (iii) through (vi) hereof, be accompanied by an instruction to
      suspend the use of the Prospectus until the requisite changes have been made)
      as
      promptly as reasonably possible (and, in the case of (i)(A) below, not less
      than
      one (1) Trading Day prior to such filing) and (if requested by any such Person)
      confirm such notice in writing no later than one (1) Trading Day following
      the
      day (i)(A) when a Prospectus or any Prospectus supplement or post-effective
      amendment to a Registration Statement is proposed to be filed; (B) when the
      Commission notifies the Company whether there will be a “review” of such
      Registration Statement and whenever the Commission comments in writing on such
      Registration Statement; and (C) with respect to a Registration Statement or
      any
      post-effective amendment, when the same has become effective; (ii) of any
      request by the Commission or any other Federal or state governmental authority
      for amendments or supplements to a Registration Statement or Prospectus or
      for
      additional information; (iii) of the issuance by the Commission or any other
      federal or state governmental authority of any stop order suspending the
      effectiveness of a Registration Statement covering any or all of the Registrable
      Securities or the initiation of any Proceedings for that purpose; (iv) of the
      receipt by the Company of any notification with respect to the suspension of
      the
      qualification or exemption from qualification of any of the Registrable
      Securities for sale in any jurisdiction, or the initiation or threatening of
      any
      Proceeding for such purpose; (v) of the occurrence of any event or passage
      of
      time that makes the financial statements included in a Registration Statement
      ineligible for inclusion therein or any statement made in a Registration
      Statement or Prospectus or any document incorporated or deemed to be
      incorporated therein by reference untrue in any material respect or that
      requires any revisions to a Registration Statement, Prospectus or other
      documents so that, in the case of a Registration Statement or the Prospectus,
      as
      the case may be, it will not contain any untrue statement of a material fact
      or
      omit to state any material fact required to be stated therein or necessary
      to
      make the statements therein, in light of the circumstances under which they
      were
      made, not misleading; and (vi) the occurrence or existence of any pending
      corporate development with respect to the Company that the Company believes
      may
      be material and that, in the determination of the Company, makes it not in
      the
      best interest of the Company to allow continued availability of a Registration
      Statement or Prospectus; provided that any and all of such information shall
      remain confidential to each Holder until such information otherwise becomes
      public, unless disclosure by a Holder is required by law; provided,
      further,
      notwithstanding each Holder’s agreement to keep such information confidential,
      the Holders make no acknowledgement that any such information is material,
      non-public information.

     

    
      
        
        

      

      
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    (e) Use
      its
      good faith commercially reasonable efforts to avoid the issuance of, or, if
      issued, obtain the withdrawal of (i) any order suspending the effectiveness
      of a
      Registration Statement, or (ii) any suspension of the qualification (or
      exemption from qualification) of any of the Registrable Securities for sale
      in
      any jurisdiction, at the earliest practicable moment.

     

    (f) Furnish
      to each Holder, without charge, at least one (1) conformed copy of each such
      Registration Statement and each amendment thereto, including financial
      statements and schedules, all documents incorporated or deemed to be
      incorporated therein by reference to the extent requested by such Person, and
      all exhibits to the extent requested by such Person (including those previously
      furnished or incorporated by reference) promptly after the filing of such
      documents with the Commission.

     

    (g) Subject
      to the terms of this Agreement, the Company hereby consents to the use of such
      Prospectus and each amendment or supplement thereto by each of the selling
      Holders in connection with the offering and sale of the Registrable Securities
      covered by such Prospectus and any amendment or supplement thereto, except
      after
      the giving of any notice pursuant to Section 3(d).

     

    
      
        
        

      

      
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    (h) If
      NASDR
      Rule 2710 requires any broker-dealer to make a filing prior to executing a
      sale
      by a Holder, the Company shall (i) make an Issuer Filing with the NASDR, Inc.
      Corporate Financing Department pursuant to proposed NASDR Rule
      2710(b)(10)(A)(i), (ii) respond within five (5) Trading Days to any comments
      received from NASDR in connection therewith, and (iii) pay the filing fee
      required in connection therewith.

     

    (i) Prior
      to
      any resale of Registrable Securities by a Holder, use its commercially
      reasonable efforts to register or qualify or cooperate with the selling Holders
      in connection with the registration or qualification (or exemption from the
      Registration or qualification) of such Registrable Securities for the resale
      by
      the Holder under the securities or Blue Sky laws of such jurisdictions within
      the United States as any Holder reasonably requests in writing, to keep each
      registration or qualification (or exemption therefrom) effective during the
      Effectiveness Period and to do any and all other acts or things reasonably
      necessary to enable the disposition in such jurisdictions of the Registrable
      Securities covered by each Registration Statement; provided, that the Company
      shall not be required to qualify generally to do business in any jurisdiction
      where it is not then so qualified, subject the Company to any material tax
      in
      any such jurisdiction where it is not then so subject or file a general consent
      to service of process in any such jurisdiction.

     

    (j) If
      requested by the Holders, cooperate with the Holders to facilitate the timely
      preparation and delivery of certificates representing Registrable Securities
      to
      be delivered to a transferee pursuant to a Registration Statement, which
      certificates shall be free, to the extent permitted by the Purchase Agreement,
      of all restrictive legends, and to enable such Registrable Securities to be
      in
      such denominations and registered in such names as any such Holders may
      request.

     

    (k) Upon
      the
      occurrence of any event contemplated by this Section 3, as promptly as
      reasonably possible under the circumstances taking into account the Company’s
      good faith assessment of any adverse consequences to the Company and its
      stockholders of the premature disclosure of such event, prepare a supplement
      or
      amendment, including a post-effective amendment, to a Registration Statement
      or
      a supplement to the related Prospectus or any document incorporated or deemed
      to
      be incorporated therein by reference, and file any other required document
      so
      that, as thereafter delivered, neither a Registration Statement nor such
      Prospectus will contain an untrue statement of a material fact or omit to state
      a material fact required to be stated therein or necessary to make the
      statements therein, in light of the circumstances under which they were made,
      not misleading. If the Company notifies the Holders in accordance with clauses
      (iii) through (vi) of Section 3(d) above to suspend the use of any Prospectus
      until the requisite changes to such Prospectus have been made, then the Holders
      shall suspend use of such Prospectus. The Company will use its good faith
      commercially reasonable efforts to ensure that the use of the Prospectus may
      be
      resumed as promptly as is practicable. The Company shall be entitled to exercise
      its right under this Section 3(k) to suspend the availability of a Registration
      Statement and Prospectus, subject to the payment of partial liquidated damages
      pursuant to Section 2(b), for a period not to exceed sixty (60) calendar days
      (which need not be consecutive days) in any 12- month period.

     

    
      
        
        

      

      
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    (l) Comply
      with all applicable rules and regulations of the Commission.

     

    (m) The
      Company may require each selling Holder to furnish to the Company a certified
      statement as to the number of shares of Common Stock beneficially owned by
      such
      Holder and, if required by the Commission, the natural persons thereof that
      have
      voting and dispositive control over the Shares. During any periods that the
      Company is unable to meet its obligations hereunder with respect to the
      registration of the Registrable Securities solely because any Holder fails
      to
      furnish such information within three Trading Days of the Company’s request, any
      liquidated damages that are accruing at such time as to such Holder only shall
      be tolled and any Event that may otherwise occur solely because of such delay
      shall be suspended as to such Holder only, until such information is delivered
      to the Company.

     

    4. Registration
      Expenses.
      All
      fees and expenses (exclusive of underwriting discounts and commissions) incident
      to the performance of or compliance with this Agreement by the Company shall
      be
      borne by the Company whether or not any Registrable Securities are sold pursuant
      to a Registration Statement; provided,
      however,
      the
      Company shall pay up to a maximum of $30,000 for reasonable fees and expenses
      of
      no more than one special counsel for the Purchasers if the Registration
      Statement is on Form S-3 or up to a maximum of $60,000 for reasonable fees
      and
      expenses of no more than one special counsel for the Purchasers if the Company
      is not then eligible to register for resale the Registrable Securities on Form
      S-3. Subject to the foregoing sentence, the fees and expenses shall include
      (i)
      all registration and filing fees (including, without limitation, fees and
      expenses (A) with respect to filings required to be made with any Trading Market
      on which the Common Stock is then listed for trading, (B) in compliance with
      applicable state securities or Blue Sky laws reasonably agreed to by the Company
      in writing (including, without limitation, fees and disbursements of counsel
      for
      the Company in connection with Blue Sky qualifications or exemptions of the
      Registrable Securities) and (C) if not previously paid by the Company in
      connection with an Issuer Filing, with respect to any filing that may be
      required to be made by any broker through which a Holder intends to make sales
      of Registrable Securities with NASD Regulation, Inc. pursuant to the NASD Rule
      2710, so long as the broker is receiving no more than a customary brokerage
      commission in connection with such sale, (ii) printing expenses (including,
      without limitation, expenses of printing certificates for Registrable
      Securities, (iii) messenger, telephone and delivery expenses, (iv) fees and
      disbursements of counsel for the Company, (v) Securities Act liability
      insurance, if the Company so desires such insurance, and (vi) fees and expenses
      of all other Persons retained by the Company in connection with the consummation
      of the transactions contemplated by this Agreement. In addition, the Company
      shall be responsible for all of its internal expenses incurred in connection
      with the consummation of the transactions contemplated by this Agreement
      (including, without limitation, all salaries and expenses of its officers and
      employees performing legal or accounting duties), the expense of any annual
      audit and the fees and expenses incurred in connection with the listing of
      the
      Registrable Securities on any securities exchange as required hereunder. In
      no
      event shall the Company be responsible for any broker or similar commissions
      of
      any Holder or, except to the extent provided for in the Transaction Documents,
      any legal fees or other costs of the Holders.

     

    
      
        
        

      

      
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    5. Indemnification

     

    (a) Indemnification
      by the Company.
      The
      Company shall, notwithstanding any termination of this Agreement, indemnify
      and
      hold harmless each Holder, the officers, directors, members, partners, agents,
      brokers (including brokers who offer and sell Registrable Securities as
      principal as a result of a pledge or any failure to perform under a margin
      call
      of Common Stock), investment advisors and employees (and any other Persons
      with
      a functionally equivalent role of a Person holding such titles, notwithstanding
      a lack of such title or any other title) of each of them, each Person who
      controls any such Holder (within the meaning of Section 15 of the Securities
      Act
      or Section 20 of the Exchange Act) and the officers, directors, members,
      shareholders, partners, agents and employees (and any other Persons with a
      functionally equivalent role of a Person holding such titles, notwithstanding
      a
      lack of such title or any other title)of each such controlling Person, to the
      fullest extent permitted by applicable law, from and against any and all losses,
      claims, damages, liabilities, costs (including, without limitation, reasonable
      attorneys’ fees) and expenses (collectively, “Losses”),
      as
      incurred, arising out of or relating to (1) any untrue or alleged untrue
      statement of a material fact contained in a Registration Statement, any
      Prospectus or any form of prospectus or in any amendment or supplement thereto
      or in any preliminary prospectus, or arising out of or relating to any omission
      or alleged omission of a material fact required to be stated therein or
      necessary to make the statements therein (in the case of any Prospectus or
      form
      of prospectus or supplement thereto, in light of the circumstances under which
      they were made) not misleading, or (2) any violation or alleged violation by
      the
      Company of the Securities Act, Exchange Act or any state securities law, or
      any
      rule or regulation thereunder, in connection with the performance of its
      obligations under this Agreement, except to the extent, but only to the extent,
      that (i) such untrue statements or omissions are based solely upon information
      regarding such Holder furnished in writing to the Company by such Holder
      expressly for use therein, or to the extent that such information relates to
      such Holder or such Holder’s proposed method of distribution of Registrable
      Securities and was reviewed and expressly approved in writing by such Holder
      expressly for use in a Registration Statement, such Prospectus or such form
      of
      Prospectus or in any amendment or supplement thereto (it being understood that
      the Holder has approved Annex A hereto for this purpose), (ii) in the case
      of an
      occurrence of an event of the type specified in Section 3(d)(iii)-(vi), the
      use
      by such Holder of an outdated or defective Prospectus after the Company has
      notified such Holder in writing that the Prospectus is outdated or defective
      and
      prior to the receipt by such Holder of the Advice contemplated in Section 6(d)
      or (iii) willful misconduct on the part of such Holder. The Company shall notify
      the Holders promptly of the institution, threat or assertion of any Proceeding
      arising from or in connection with the transactions contemplated by this
      Agreement of which the Company is aware.

     

    (b) Indemnification
      by Holders.
      Each
      Holder shall, severally and not jointly, indemnify and hold harmless the
      Company, its directors, officers, agents and employees, each Person who controls
      the Company (within the meaning of Section 15 of the Securities Act and Section
      20 of the Exchange Act), and the directors, officers, agents or employees of
      such controlling Persons, to the fullest extent permitted by applicable law,
      from and against all Losses, as incurred, to the extent arising out of or based
      solely upon: (x) such Holder’s failure to comply with the prospectus delivery
      requirements of the Securities Act or (y) any untrue or alleged untrue statement
      of a material fact contained in any Registration Statement, any Prospectus,
      or
      any form of prospectus, or in any amendment or supplement thereto or in any
      preliminary prospectus, or arising out of or relating to any omission or alleged
      omission of a material fact required to be stated therein or necessary to make
      the statements therein not misleading (i) to the extent, but only to the extent,
      that such untrue statement or omission is contained in any information so
      furnished in writing by such Holder to the Company specifically for inclusion
      in
      such Registration Statement or such Prospectus or (ii) to the extent that such
      information relates to such Holder’s proposed method of distribution of
      Registrable Securities and was reviewed and expressly approved in writing by
      such Holder expressly for use in a Registration Statement (it being understood
      that the Holder has approved Annex A hereto for this purpose), such Prospectus
      or such form of Prospectus or in any amendment or supplement thereto or (iii)
      in
      the case of an occurrence of an event of the type specified in Section
      3(d)(iii)-(vi), the use by such Holder of an outdated or defective Prospectus
      after the Company has notified such Holder in writing that the Prospectus is
      outdated or defective and prior to the receipt by such Holder of the Advice
      contemplated in Section 6(d). In no event shall the liability of any selling
      Holder hereunder be greater in amount than the dollar amount of the net proceeds
      received by such Holder upon the sale of the Registrable Securities giving
      rise
      to such indemnification obligation.

     

    
      
        
        

      

      
        9

        
          

        

      

      
        
        

      

    

    (c) Conduct
      of Indemnification Proceedings.
      If any
      Proceeding shall be brought or asserted against any Person entitled to indemnity
      hereunder (an “Indemnified
      Party”),
      such
      Indemnified Party shall promptly notify the Person from whom indemnity is sought
      (the “Indemnifying
      Party”)
      in
      writing, and the Indemnifying Party shall have the right to assume the defense
      thereof, including the employment of counsel reasonably satisfactory to the
      Indemnified Party and the payment of all fees and expenses incurred in
      connection with defense thereof; provided, that the failure of any Indemnified
      Party to give such notice shall not relieve the Indemnifying Party of its
      obligations or liabilities pursuant to this Agreement, except (and only) to
      the
      extent that it shall be finally determined by a court of competent jurisdiction
      (which determination is not subject to appeal or further review) that such
      failure shall have prejudiced the Indemnifying Party.

     

    An
      Indemnified Party shall have the right to employ separate counsel in any such
      Proceeding and to participate in the defense thereof, but the fees and expenses
      of such counsel shall be at the expense of such Indemnified Party or Parties
      unless: (1) the Indemnifying Party has agreed in writing to pay such fees and
      expenses; (2) the Indemnifying Party shall have failed promptly to assume the
      defense of such Proceeding and to employ counsel reasonably satisfactory to
      such
      Indemnified Party in any such Proceeding; or (3) the named parties to any such
      Proceeding (including any impleaded parties) include both such Indemnified
      Party
      and the Indemnifying Party, and counsel to the Indemnified Party shall
      reasonably believe that a material conflict of interest is likely to exist
      if
      the same counsel were to represent such Indemnified Party and the Indemnifying
      Party (in which case, if such Indemnified Party notifies the Indemnifying Party
      in writing that it elects to employ separate counsel at the expense of the
      Indemnifying Party, the Indemnifying Party shall not have the right to assume
      the defense thereof and the reasonable fees and expenses of no more than one
      separate counsel shall be at the expense of the Indemnifying Party). The
      Indemnifying Party shall not be liable for any settlement of any such Proceeding
      effected without its written consent, which consent shall not be unreasonably
      withheld or delayed. No Indemnifying Party shall, without the prior written
      consent of the Indemnified Party, effect any settlement of any pending
      Proceeding in respect of which any Indemnified Party is a party, unless such
      settlement includes an unconditional release of such Indemnified Party from
      all
      liability on claims that are the subject matter of such Proceeding.

     

    
      
        
        

      

      
        10

        
          

        

      

      
        
        

      

    

    Subject
      to the terms of this Agreement, all reasonable fees and expenses of the
      Indemnified Party (including reasonable fees and expenses to the extent incurred
      in connection with investigating or preparing to defend such Proceeding in
      a
      manner not inconsistent with this Section) shall be paid to the Indemnified
      Party, as incurred, within ten (10) Trading Days of written notice thereof
      to
      the Indemnifying Party; provided,
      that
      the Indemnified Party shall promptly reimburse the Indemnifying Party for that
      portion of such fees and expenses applicable to such actions for which such
      Indemnified Party is judicially determined to be not entitled to indemnification
      hereunder.

     

    (d) Contribution.
      If the
      indemnification under Section 5(a) or 5(b) is unavailable to an Indemnified
      Party or insufficient to hold an Indemnified Party harmless for any Losses,
      then
      each Indemnifying Party shall contribute to the amount paid or payable by such
      Indemnified Party, in such proportion as is appropriate to reflect the relative
      fault of the Indemnifying Party and Indemnified Party in connection with the
      actions, statements or omissions that resulted in such Losses as well as any
      other relevant equitable considerations. The relative fault of such Indemnifying
      Party and Indemnified Party shall be determined by reference to, among other
      things, whether any action in question, including any untrue or alleged untrue
      statement of a material fact or omission or alleged omission of a material
      fact,
      has been taken or made by, or relates to information supplied by, such
      Indemnifying Party or Indemnified Party, and the parties’ relative intent,
      knowledge, access to information and opportunity to correct or prevent such
      action, statement or omission. The amount paid or payable by a party as a result
      of any Losses shall be deemed to include, subject to the limitations set forth
      in this Agreement, any reasonable attorneys’ or other reasonable fees or
      reasonable expenses incurred by such party in connection with any Proceeding
      to
      the extent such party would have been indemnified for such fees or expenses
      if
      the indemnification provided for in this Section was available to such party
      in
      accordance with its terms.

     

    The
      parties hereto agree that it would not be just and equitable if contribution
      pursuant to this Section 5(d) were determined by pro rata allocation or by
      any
      other method of allocation that does not take into account the equitable
      considerations referred to in the immediately preceding paragraph.
      Notwithstanding the provisions of this Section 5(d), no Holder shall be required
      to contribute, in the aggregate, any amount in excess of the amount by which
      the
      proceeds actually received by such Holder from the sale of the Registrable
      Securities subject to the Proceeding exceeds the amount of any damages that
      such
      Holder has otherwise been required to pay by reason of such untrue or alleged
      untrue statement or omission or alleged omission, except in the case of fraud
      by
      such Holder.

     

    The
      indemnity and contribution agreements contained in this Section are in addition
      to any liability that the Indemnifying Parties may have to the Indemnified
      Parties.

     

    
      
        
        

      

      
        11

        
          

        

      

      
        
        

      

    

    6. Miscellaneous

     

    (a) Remedies.
      In the
      event of a breach by the Company or by a Holder, of any of their respective
      obligations under this Agreement, each Holder or the Company, as the case may
      be, in addition to being entitled to exercise all rights granted by law and
      under this Agreement, including recovery of damages, will be entitled to seek
      specific performance of its rights under this Agreement. The Company and each
      Holder agree that monetary damages would not provide adequate compensation
      for
      any losses incurred by reason of a breach by it of any of the provisions of
      this
      Agreement and hereby further agrees that, in the event of any action for
      specific performance in respect of such breach, it shall not assert or shall
      waive the defense that a remedy at law would be adequate.

     

    (b) Subsequent
      Registration Rights.
      The
      Company shall not file any other registration statements until the initial
      Registration Statement required hereunder is declared effective by the
      Commission, provided that this Section 6(b) shall not prohibit the Company
      from
      filing amendments to registration statements already filed.

     

    (c) No
      Piggyback on Registrations.
      Neither
      the Company nor any of its security holders (other than the Holders in such
      capacity pursuant hereto) may include securities of the Company in the initial
      Registration Statement other than the Registrable Securities. 

     

    (d) Compliance.
      Each
      Holder covenants and agrees that it will comply with the prospectus delivery
      requirements of the Securities Act as applicable to it in connection with sales
      of Registrable Securities pursuant to a Registration Statement.

     

    (e) Discontinued
      Disposition.
      Each
      Holder agrees by its acquisition of Registrable Securities that, upon receipt
      of
      a notice from the Company of the occurrence of any event of the kind described
      in Section 3(d), such Holder will forthwith discontinue disposition of such
      Registrable Securities under a Registration Statement until it is advised in
      writing (the “Advice”)
      by the
      Company that the use of the applicable Prospectus (as it may have been
      supplemented or amended) may be resumed. The Company will use its good faith
      commercially reasonable efforts to ensure that the use of the Prospectus may
      be
      resumed as promptly as it practicable. The
      Company agrees and acknowledges that any periods during which the Holder is
      required to discontinue the disposition of the Registrable Securities hereunder
      shall be subject to the provisions of Section 2(b).

     

    (f) Piggy-Back
      Registrations.
      If at
      any time during the Effectiveness Period there is not an effective Registration
      Statement covering all of the Registrable Securities and the Company shall
      determine to prepare and file with the Commission a registration statement
      relating to an offering for its own account or the account of others under
      the
      Securities Act of any of its equity securities, other than on Form S-4 or Form
      S-8 (each as promulgated under the Securities Act) or their then equivalents
      relating to equity securities to be issued solely in connection with any
      acquisition of any entity or business or equity securities issuable in
      connection with the stock option or other employee benefit plans, then the
      Company shall send to each Holder a written notice of such determination and,
      if
      within fifteen days after the date of such notice, any such Holder shall so
      request in writing, the Company shall include in such registration statement
      all
      or any part of such Registrable Securities such Holder requests to be
      registered; provided,
      however,
      that,
      the Company shall not be required to register any Registrable Securities
      pursuant to this Section 6(e) that are eligible for resale pursuant to Rule
      144(k) promulgated under the Securities Act or that are the subject of a then
      effective Registration Statement.

     

    
      
        
        

      

      
        12

        
          

        

      

      
        
        

      

    

    (g) Amendments
      and Waivers.
      The
      provisions of this Agreement, including the provisions of this sentence, may
      not
      be amended, modified or supplemented, and waivers or consents to departures
      from
      the provisions hereof may not be given, unless the same shall be in writing
      and
      signed by the Company and each Holder of the then outstanding Registrable
      Securities. Notwithstanding the foregoing, a waiver or consent to depart from
      the provisions hereof with respect to a matter that relates exclusively to
      the
      rights of Holders and that does not directly or indirectly affect the rights
      of
      other Holders may be given by Holders of all of the Registrable Securities
      to
      which such waiver or consent relates; provided,
      however,
      that
      the provisions of this sentence may not be amended, modified, or supplemented
      except in accordance with the provisions of the immediately preceding
      sentence.

     

    (h) Notices.
      Any and
      all notices or other communications or deliveries required or permitted to
      be
      provided hereunder shall be delivered as set forth in the Purchase
      Agreement.

     

    (i) Successors
      and Assigns.
      This
      Agreement shall inure to the benefit of and be binding upon the successors
      and
      permitted assigns of each of the parties and shall inure to the benefit of
      each
      Holder. Each Holder may assign their respective rights hereunder in the manner
      and to the Persons as permitted under the Purchase Agreement.

     

    (j) No
      Inconsistent Agreements.
      Neither
      the Company nor any of its Subsidiaries has entered, as of the date hereof,
      nor
      shall the Company or any of its Subsidiaries, on or after the date of this
      Agreement, enter into any agreement with respect to its securities, that would
      have the effect of impairing the rights granted to the Holders in this Agreement
      or otherwise conflicts with the provisions hereof. Except as set forth on
Schedule
      6(i),
      neither
      the Company nor any of its subsidiaries has previously entered into any
      agreement granting any registration rights with respect to any of its securities
      to any Person that have not been satisfied in full.

     

    (k) Execution
      and Counterparts.
      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.

     

    
      
        
        

      

      
        13

        
          

        

      

      
        
        

      

    

    (l) Governing
      Law.
      All
      questions concerning the construction, validity, enforcement and interpretation
      of this Agreement shall be determined in accordance with the provisions of
      the
      Purchase Agreement.

     

    (m) Cumulative
      Remedies.
      The
      remedies provided herein are cumulative and not exclusive of any other remedies
      provided by law.

     

    (n) Severability.
      If any
      term, provision, covenant or restriction of this Agreement is held by a court
      of
      competent jurisdiction to be invalid, illegal, void or unenforceable, the
      remainder of the terms, provisions, covenants and restrictions set forth herein
      shall remain in full force and effect and shall in no way be affected, impaired
      or invalidated, and the parties hereto shall use their good faith commercially
      reasonable efforts to find and employ an alternative means to achieve the same
      or substantially the same result as that contemplated by such term, provision,
      covenant or restriction. It is hereby stipulated and declared to be the
      intention of the parties that they would have executed the remaining terms,
      provisions, covenants and restrictions without including any of such that may
      be
      hereafter declared invalid, illegal, void or unenforceable.

     

    (o) Termination.
      Without
      any additional action of the parties, this Agreement shall automatically
      terminate and be of no further force and effect at the earlier of such time
      as
      (a) the Preferred Financing (as defined in the Purchase Agreement) has occurred
      or (b) the Holders no longer hold Registrable Securities. 

     

    (p) Headings.
      The
      headings in this Agreement are for convenience only, do not constitute a part
      of
      this Agreement, and shall not be deemed to limit or affect any of the provisions
      hereof.

     

    (q) Independent
      Nature of Holders’ Obligations and Rights.
      The
      obligations of each Holder hereunder are several and not joint with the
      obligations of any other Holder hereunder, and no Holder shall be responsible
      in
      any way for the performance of the obligations of any other Holder hereunder.
      Nothing contained herein or in any other agreement or document delivered at
      any
      closing, and no action taken by any Holder pursuant hereto or thereto, shall
      be
      deemed to constitute the Holders as a partnership, an association, a joint
      venture or any other kind of entity, or create a presumption that the Holders
      are in any way acting in concert with respect to such obligations or the
      transactions contemplated by this Agreement. Each Holder shall be entitled
      to
      protect and enforce its rights, including without limitation the rights arising
      out of this Agreement, and it shall not be necessary for any other Holder to
      be
      joined as an additional party in any proceeding for such purpose.

     

    *************************

    


     

    
      
        
        

      

      
        14

        
          

        

      

      
        
        

      

    


    IN
      WITNESS WHEREOF, the parties have executed this Registration Rights Agreement
      as
      of the date first written above.

     

    
      	 	 	 
	 	
              ALTEON
                INC. 

            
	 
 	 
 	 
 
	 	By:  	/s/ Noah
              Berkowitz
	 	
              
Name:
              Noah Berkowitz 
              Title:
                President and Chief Executive Officer

            
	 	 




     

    
 

    


    [SIGNATURE
      PAGE OF HOLDERS FOLLOWS]

     

    
      
        
        

      

      
        15

        
          

        

      

      
        
        

      

    

    [SIGNATURE
      PAGE OF HOLDERS TO ALTEON REGISTRATION RIGHTS AGREEMENT]

    


    


    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 
is
      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, 
is
      general partner

    


    By: /s/
      Felix
      Baker                          

Name:
      Felix Baker, Ph.D.
Title:
      Managing Member

    


    
      
        
        

      

      
        16

        
          

        

      

      
        
        

      

    

    


    ANNEX
      A

     

    Plan
      of Distribution

     

    Each
      Selling Stockholder (the “Selling
      Stockholders”)
      of the
      common stock and any of their pledgees, assignees and successors-in-interest
      may, from time to time, sell any or all of their shares of common stock on
      the
      American Stock Exchange or any other stock exchange, market or trading facility
      on which the shares are traded or in private transactions. These sales may
      be at
      fixed or negotiated prices. A Selling Stockholder may use any one or more of
      the
      following methods when selling shares:

     

    
      	 	
              ·

            	
              ordinary
                brokerage transactions and transactions in which the broker-dealer
                solicits purchasers;

            


    

     

    
      	 	
              ·

            	
              block
                trades in which the broker-dealer will attempt to sell the shares
                as agent
                but may position and resell a portion of the block as principal to
                facilitate the transaction;

            


    

     

    
      	 	
              ·

            	
              purchases
                by a broker-dealer as principal and resale by the broker-dealer for
                its
                account;

            


    

     

    
      	 	
              ·

            	
              an
                exchange distribution in accordance with the rules of the applicable
                exchange;

            


    

     

    
      	 	
              ·

            	
              privately
                negotiated transactions;

            


    

     

    
      	 	
              ·

            	
              settlement
                of short sales entered into after the effective date of the registration
                statement of which this prospectus is a
                part;

            


    

     

    
      	 	
              ·

            	
              broker-dealers
                may agree with the Selling Stockholders to sell a specified number
                of such
                shares at a stipulated price per
                share;

            


    

     

    
      	 	
              ·

            	
              through
                the writing or settlement of options or other hedging transactions,
                whether through an options exchange or otherwise;
                

            


    

     

    
      	 	
              ·

            	
              a
                combination of any such methods of sale;
                or

            


    

     

    
      	 	
              ·

            	
              any
                other method permitted pursuant to applicable
                law.

            


    

     

    The
      Selling Stockholders may also sell shares under Rule 144 under the Securities
      Act of 1933, as amended (the “Securities
      Act”),
      if
      available, rather than under this prospectus.

     

    Broker-dealers
      engaged by the Selling Stockholders may arrange for other brokers-dealers to
      participate in sales. Broker-dealers may receive commissions or discounts from
      the Selling Stockholders (or, if any broker-dealer acts as agent for the
      purchaser of shares, from the purchaser) in amounts to be negotiated, but,
      except as set forth in a supplement to this Prospectus, in the case of an agency
      transaction not in excess of a customary brokerage commission in compliance
      with
      NASDR Rule 2440; and in the case of a principal transaction a markup or markdown
      in compliance with NASDR IM-2440. 

     

    
      
        
        

      

      
        17

        
          

        

      

      
        
        

      

    

    In
      connection with the sale of the common stock or interests therein, the Selling
      Stockholders may enter into hedging transactions with broker-dealers or other
      financial institutions, which may in turn engage in short sales of the Common
      Stock in the course of hedging the positions they assume. The Selling
      Stockholders may also sell shares of the common stock short and deliver these
      securities to close out their short positions, or loan or pledge the common
      stock to broker-dealers that in turn may sell these securities. The Selling
      Stockholders may also enter into option or other transactions with
      broker-dealers or other financial institutions or the creation of one or more
      derivative securities which require the delivery to such broker-dealer or other
      financial institution of shares offered by this prospectus, which shares such
      broker-dealer or other financial institution may resell pursuant to this
      prospectus (as supplemented or amended to reflect such
      transaction).

     

    The
      Selling Stockholders and any broker-dealers or agents that are involved in
      selling the shares may be deemed to be “underwriters” within the meaning of the
      Securities Act in connection with such sales. In such event, any commissions
      received by such broker-dealers or agents and any profit on the resale of the
      shares purchased by them may be deemed to be underwriting commissions or
      discounts under the Securities Act. Each Selling Stockholder has informed the
      Company that it does not have any written or oral agreement or understanding,
      directly or indirectly, with any person to distribute the Common Stock. In
      no
      event shall any broker-dealer receive fees, commissions and markups which,
      in
      the aggregate, would exceed eight percent (8%).

     

    The
      Company is required to pay certain fees and expenses incurred by the Company
      incident to the registration of the shares. The Company has agreed to indemnify
      the Selling Stockholders against certain losses, claims, damages and
      liabilities, including liabilities under the Securities Act. 

     

    Because
      Selling Stockholders may be deemed to be “underwriters” within the meaning of
      the Securities Act, they will be subject to the prospectus delivery requirements
      of the Securities Act including Rule 172 thereunder. In addition, any securities
      covered by this prospectus which qualify for sale pursuant to Rule 144 under
      the
      Securities Act may be sold under Rule 144 rather than under this prospectus.
      Each Selling Stockholder has advised us that they have not entered into any
      written or oral agreements, understandings, or arrangements with any underwriter
      or broker-dealer regarding the sale of the resale shares. There is no
      underwriter or coordinating broker acting in connection with the proposed sale
      of the resale shares by the Selling Stockholders.

     

    We
      agreed
      to keep this prospectus effective until the earlier of (i) the date on which
      the
      shares may be resold by the Selling Stockholders without registration and
      without regard to any volume limitations by reason of Rule 144(k) under the
      Securities Act or any other rule of similar effect or (ii) all of the shares
      have been sold pursuant to this prospectus or Rule 144 under the Securities
      Act
      or any other rule of similar effect. The resale shares will be sold only through
      registered or licensed brokers or dealers if required under applicable state
      securities laws. In addition, in certain states, the resale shares may not
      be
      sold unless they have been registered or qualified for sale in the applicable
      state or an exemption from the registration or qualification requirement is
      available and is complied with.

     

    
      
        
        

      

      
        18

        
          

        

      

      
        
        

      

    

    Under
      applicable rules and regulations under the Exchange Act, any person engaged
      in
      the distribution of the resale shares may not simultaneously engage in market
      making activities with respect to the common stock for the applicable restricted
      period, as defined in Regulation M, prior to the commencement of the
      distribution. In addition, the Selling Stockholders will be subject to
      applicable provisions of the Exchange Act and the rules and regulations
      thereunder, including Regulation M, which may limit the timing of purchases
      and
      sales of shares of the common stock by the Selling Stockholders or any other
      person. We will make copies of this prospectus available to the Selling
      Stockholders and have informed them of the need to deliver a copy of this
      prospectus to each purchaser at or prior to the time of the sale.

     

    


     

    
      
        
        

      

      
        19

        
          

        

      

      
        
        

      

    

    Annex
      B

     

    ALTEON
      INC. 

     

    Selling
      Securityholder Notice and Questionnaire

     

    The
      undersigned beneficial owner of common stock, par value $0.01 per share (the
      “Common
      Stock”),
      of
      Alteon Inc., a Delaware corporation (the “Company”),
      (the
“Registrable
      Securities”)
      understands that the Company has filed or intends to file with the Securities
      and Exchange Commission (the “Commission”)
      a
      registration statement on Form S-3 (the “Registration
      Statement”)
      for
      the registration and resale under Rule 415 of the Securities Act of 1933, as
      amended (the “Securities
      Act”),
      of
      the Registrable Securities, in accordance with the terms of the Registration
      Rights Agreement, dated as of January 11, 2007 (the “Registration
      Rights Agreement”),
      among
      the Company and the Purchasers named therein. A copy of the Registration Rights
      Agreement is available from the Company upon request at the address set forth
      below. All capitalized terms not otherwise defined herein shall have the
      meanings ascribed thereto in the Registration Rights Agreement.

     

    Certain
      legal consequences arise from being named as a selling securityholder in the
      Registration Statement and the related prospectus. Accordingly, holders and
      beneficial owners of Registrable Securities are advised to consult their own
      securities law counsel regarding the consequences of being named or not being
      named as a selling securityholder in the Registration Statement and the related
      prospectus.

     

    NOTICE

     

    The
      undersigned beneficial owner (the “Selling
      Securityholder”)
      of
      Registrable Securities hereby elects to include the Registrable Securities
      owned
      by it and listed below in Item 3 (unless otherwise specified under such Item
      3)
      in the Registration Statement.

     

    
      
        
        

      

      
        20

        
          

        

      

      
        
        

      

    

    The
      undersigned hereby provides the following information to the Company and
      represents and warrants that such information is accurate:

     

    QUESTIONNAIRE

     

    1. Name.

     

    
      	 	
              (a)

            	
              Full
                Legal Name of Selling
                Securityholder

            


    

     

    
      	 	 
	 	 


    

    


    
      	 	
              (b)

            	
              Full
                Legal Name of Registered Holder (if not the same as (a) above) through
                which Registrable Securities Listed in Item 3 below are
                held:

            


    

     

    
      	 	 
	 	 


    

    


    
      	 	
              (c)

            	
              Full
                Legal Name of Natural Control Person (which means a natural person
                who
                directly or indirectly alone or with others has power to vote or
                dispose
                of the securities covered by the
                questionnaire):

            


    

     

    
      	 	 
	 	 


    

    


     

    2.
      Address for Notices to Selling Securityholder:

     

    
      	 
	 
	 
	
              Telephone: 

            	
            
	
              Fax: 

            	
            
	
              Contact
                Person: 

            	
            


    

    


    3.
      Beneficial Ownership of Registrable Securities:

     

    
      	 	
              (a)

            	
              Type
                and Number of Registrable Securities beneficially owned (not including
                the
                Registrable Securities that are issuable pursuant to the Purchase
                Agreement):

            


    

     

    
      	 	 
	 	 
	 	 
	 	 


    

    


    
      
        
        

      

      
        21

        
          

        

      

      
        
        

      

    

     

    4.
      Broker-Dealer Status:

     

    
      	 	
              (a)

            	
              Are
                you a broker-dealer?

            


    

     

    Yes o    No o

     

    
      	 	
              (b)

            	
              If
                “yes” to Section 4(a), did you receive your Registrable Securities as
                compensation for investment banking services to the
                Company.

            


    

    
       

      Yes o    No o

       

    

    
      	 	
              Note:

            	
              If
                no, the Commission’s staff has indicated that you should be identified as
                an underwriter in the Registration
                Statement.

            


    

     

    
      	 	
              (c)

            	
              Are
                you an affiliate of a
                broker-dealer?

            


    

    
       

      Yes o    No o

       

    

    
      	 	
              (d)

            	
              If
                you are an affiliate of a broker-dealer, do you certify that you
                bought
                the Registrable Securities in the ordinary course of business, and
                at the
                time of the purchase of the Registrable Securities to be resold,
                you had
                no agreements or understandings, directly or indirectly, with any
                person
                to distribute the Registrable
                Securities?

            


    

    
       

      Yes o    No o

       

    

    
      	 	
              Note:

            	
              If
                no, the Commission’s staff has indicated that you should be identified as
                an underwriter in the Registration
                Statement.

            


    

     

    5.
      Beneficial Ownership of Other Securities of the Company Owned by the Selling
      Securityholder.

     

    Except
      as set forth below in this Item 5, the undersigned is not the beneficial or
      registered owner of any securities of the Company other than the Registrable
      Securities listed above in Item 3.

     

    
      	 	
              (a)

            	
              Type
                and Amount of Other Securities beneficially owned by the Selling
                Securityholder:

            


    

    
       

      
        	 	 
	 	 
	 	 
	 	 


      

      


      
        
          
          

        

        
          22

          
            

          

        

        
          
          

        

      

    

    


     

    6.
      Relationships with the Company:

     

    Except
      as set forth below, neither the undersigned nor any of its affiliates, officers,
      directors or principal equity holders (owners of 5% of more of the equity
      securities of the undersigned) has held any position or office or has had any
      other material relationship with the Company (or its predecessors or affiliates)
      during the past three years.

     

    State
      any
      exceptions here:

    
       

      
        	 	 
	 	 


      

      


    

     

    The
      undersigned agrees to promptly notify the Company of any inaccuracies or changes
      in the information provided herein that may occur subsequent to the date hereof
      at any time while the Registration Statement remains effective.

     

    By
      signing below, the undersigned consents to the disclosure of the information
      contained herein in its answers to Items 1 through 6 and the inclusion of such
      information in the Registration Statement and the related prospectus
and
      any
      amendments or supplements thereto.
      The
      undersigned understands that such information will be relied upon by the Company
      in connection with the preparation or amendment of the Registration Statement
      and the related prospectus.

     

    IN
      WITNESS WHEREOF the undersigned, by authority duly given, has caused this Notice
      and Questionnaire to be executed and delivered either in person or by its duly
      authorized agent.

     

    
      	 	 	 	 	 
	Dated: 	 	 	Beneficial
              Owner:  	 


    

     

    
      	 	 	 	 	 
	 	 	 	By:	 
	 	Name:
Title:


    

    


    PLEASE
      FAX A COPY OF THE COMPLETED AND EXECUTED NOTICE AND QUESTIONNAIRE, AND RETURN
      THE ORIGINAL BY OVERNIGHT MAIL, TO:

    


    Evan
      Bienstock

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

    One
      Financial Center 

    Boston,
      MA 02110

    Fax:
      (617)542-2241

    


    


    
      


      
        
          
          

        

        
          23