Ownership Submission
FORM 3
 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
  Phelan Mary
 2. Date of Event Requiring Statement (Month/Day/Year)
05/18/2005		 3. Issuer Name and Ticker or Trading Symbol
ALTEON INC /DE [ALT]
(Last)
(First)
(Middle)
6 CAMPUS DRIVE		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

PARSIPANNY, NJ 07054		 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security
(Instr. 4)		 2. Amount of Securities Beneficially Owned
(Instr. 4)		 3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)		 4. Nature of Indirect Beneficial Ownership
(Instr. 5)
Common Stock 860
D
 

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)		 2. Date Exercisable and Expiration Date
(Month/Day/Year)		 3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)		 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)		 6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Employee Stock Option - (Right to Buy) 08/02/2001(1) 08/02/2010 Common Stock 5,000 $ 2.56 D  
Employee Stock Option - (Right to Buy) 06/01/2001(2) 11/08/2010 Common Stock 4,800 $ 7 D  
Employee Stock Option - (Right to Buy) 12/04/2001(3) 12/04/2011 Common Stock 2,825 $ 3.9 D  
Employee Stock Option - (Right to Buy) 01/01/2003(4) 12/11/2012 Common Stock 2,880 $ 1.95 D  
Employee Stock Option - (Right to Buy) 10/08/2002(5) 10/08/2013 Common Stock 15,505 $ 2.15 D  
Employee Stock Option (Right to Buy) 01/01/2004(6) 12/10/2013 Common Stock 3,360 $ 1.56 D  
Employee Stock Option (Right to Buy) 04/01/2005(7) 12/07/2014 Common Stock 3,360 $ 1.03 D  
Employee Stock Option (Right to Buy) 05/02/2006(8) 05/02/2015 Common Stock 20,000 $ 0.58 D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Phelan Mary
6 CAMPUS DRIVE
PARSIPANNY, NJ 07054		   X      

Signatures

/s/ Wendy Milici, Attoney-in-Fact 05/18/2005
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) 1,250 vested on August 2, 2001; 3,645 vested in equal installments monthly over a 35-month period; and the remaining 105 vested on August 2, 2004
(2) 1,200 vested on June 1, 2001; June 1, 2002; December 1, 2002; and December 1, 2003
(3) 706 vested on December 4, 2001; 2,119 vested on December 31, 2002
(4) 720 vested on January 1, 2003; 1,440 on June 30, 2003; and 720 on December 31, 2003
(5) 7,752 vested on October 8, 2004; 7,753 will vest on October 8, 2005
(6) 840 vested on January 1, 2004; June 1, 2004; and 1,680 vested December 31, 2004
(7) 840 vested on April 1, 2005; 2,520 will vest on December 31, 2005
(8) 5,000 will vest on May 2, 2006; May 2, 2007; May 2, 2008; and May 2, 2009

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