As filed with the Securities and Exchange Commission on July 13, 2005

REGISTRATION NO. 333 -          

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

FORM S-8

ALTEON INC.

6 Campus Drive
Parsippany, New Jersey 07054
(Address, Including Zip Code, of Principal Executive Offices)

ALTEON INC. 2005 STOCK PLAN

KENNETH I. MOCH
PRESIDENT AND CHIEF EXECUTIVE OFFICER
ALTEON INC.
6 CAMPUS DRIVE
PARSIPPANY, NEW JERSEY 07054
(201) 934-5000
(Name, Address and Telephone Number, Including
Area Code, of Agent For Service)

with a copy to:

WILLIAM T. WHELAN, ESQ.
MINTZ, LEVIN, COHN, FERRIS, GLOVSKY AND POPEO, P.C.
ONE FINANCIAL CENTER
BOSTON, MA 02111
(617) 542-2241

CALCULATION OF REGISTRATION FEE

EXPLANATORY NOTE

     In accordance with the instructional Note to Part I of Form S-8 as promulgated by the Securities and Exchange Commission, the information specified by Part I of Form S-8 has been omitted from this Registration Statement on Form S-8 for offers of Common Stock pursuant to the Plan.

Table of Contents

PART II

INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3. Incorporation of Certain Documents by Reference.

     The following documents filed by the Registrant with the Commission are incorporated herein by reference:

     All reports and other documents filed by the Registrant after the date hereof pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Exchange Act prior to the filing of a post-effective amendment which indicates that all securities offered hereby have been sold or which deregisters all securities then remaining

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Item 4. Description of Securities.

     Not applicable.

Item 5. Interests of Named Experts and Counsel.

     The validity of the issuance of the shares of Common Stock registered under this Registration Statement has been passed upon for the Registrant by Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.

Item 6. Indemnification of Directors and Officers.

     Incorporated by reference from Part II, Item 15 of the Registrant’s Registration Statement on Form S-3, File No. 333-106048.

Item 7. Exemption from Registration Claimed.

     Not applicable.

Item 8. Exhibits.

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Item 9. Undertakings.

(1) To file, during any period in which offers or sales are being made, a post-effective amendment to this Registration Statement:

     (i) To include any prospectus required by Section 10(a)(3) of the Securities Act of 1933;

     (ii) To reflect in the prospectus any facts or events arising after the effective date of the Registration Statement (or the most recent post-effective amendment thereof) which, individually or in the aggregate, represents a fundamental change in the information set forth in the Registration Statement. Notwithstanding the foregoing, any increase or decrease in volume of securities offered (if the total dollar value of securities offered would not exceed that which was registered) and any deviation from the low or high end of the estimated maximum offering range may be reflected in the form of prospectus filed with the Commission pursuant to Rule 424(b) if, in the aggregate, the changes in volume and price represent no more than a 20% change in the maximum aggregate offering price set forth in the “Calculation of Registration Fee” table in the effective Registration Statement.

     (iii) To include any material information with respect to the plan of distribution not previously disclosed in the Registration Statement or any material change to such information in the Registration Statement;

     Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if the Registration Statement is on Form S-3, Form S-8 or Form F-3, and the information required to be included in a post-effective amendment by those paragraphs is contained in periodic reports filed with or

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furnished to the Commission by the Registrant pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934 that are incorporated by reference in this Registration Statement.

(2) That, for the purpose of determining any liability under the Securities Act of 1933, each such post-effective amendment shall be deemed to be a new registration statement relating to the securities offered therein, and the offering of such securities at that time shall be deemed to be the initial bona fide offering thereof.

(3) To remove from registration by means of a post-effective amendment any of the securities being registered which remain unsold at the termination of the offering.

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SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and has duly caused this Registration Statement to be signed on its behalf by the undersigned, thereunto duly authorized, in Parsippany, New Jersey on July 13, 2005.

POWER OF ATTORNEY

     Each person whose signature appears below constitutes and appoints Kenneth I. Moch and Mary T. Phelan, and each of them singly, his/her true and lawful attorneys-in-fact and agents, with full power of substitution and resubstitution in each of them singly, for him/her and in his/her name, place and stead, and in any and all capacities, to sign any and all amendments (including post-effective amendments) to this Registration Statement on Form S-8 of Alteon Inc., and to file the same, with all exhibits thereto and other documents in connection therewith, with the Securities and Exchange Commission, granting to the attorneys-in-fact and agents, and each of them, full power and authority to do and perform each and every act and thing requisite or necessary to be done in or about the premises, as full to all intents and purposes as he might or could do in person, hereby ratifying and confirming all that the attorneys-in-fact and agents or any of each of them or their substitute may lawfully do or cause to be done by virtue hereof.

     Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has been signed by the following persons in the capacities and on the dates indicated.

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ALTEON INC.

INDEX TO EXHIBITS FILED WITH
FORM S-8 REGISTRATION STATEMENT

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