UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G/A

o

Rule 13d-1(b)

x

Rule 13d-1(c)

o

Rule 13d-1(d)

CUSIP No. 449394105

1.

Names of Reporting Persons. I.R.S. Identification Nos. of above persons (entities only)
Sanofi-Aventis

Not applicable

2.

Check the Appropriate Box if a Member of a Group (See Instructions)

(a)

o

(b)

o

3.

SEC Use Only

4.

Citizenship or Place of Organization
The Republic of France

Number of
Shares
Beneficially
Owned by
Each
Reporting
Person With

5.

Sole Voting Power
1,986,740 shares

6.

Shared Voting Power
0 shares

7.

Sole Dispositive Power
1,986,740 shares

8.

Shared Dispositive Power
0 shares

9.

Aggregate Amount Beneficially Owned by Each Reporting Person
1,986,740 shares

10.

Check if the Aggregate Amount in Row (9) Excludes Certain Shares (See Instructions)  o

11.

Percent of Class Represented by Amount in Row (9)
14.8%

12.

Type of Reporting Person (See Instructions)
CO

Item 1.

(a)

Name of Issuer
IDM PHARMA, INC.

(b)

Address of Issuer’s Principal Executive Offices
5820 Nancy Ridge Drive, San Diego CA 92121

Item 2.

(a)

Name of Person Filing
Sanofi-Aventis

(b)

Address of Principal Business Office or, if none, Residence
174 avenue de France
75013 Paris
France

(c)

Citizenship
The Republic of France

(d)

Title of Class of Securities
Common Stock of IDM PHARMA, INC., par value $0.01 per share

(e)

CUSIP Number
449394105

Item 3.

If this statement is filed pursuant to §§240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:

Item 3 is not applicable.

(a)

o

Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o).

(b)

o

Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c).

(c)

o

Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c).

(d)

o

Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C 80a-8).

(e)

o

An investment adviser in accordance with §240.13d-1(b)(1)(ii)(E);

(f)

o

An employee benefit plan or endowment fund in accordance with §240.13d-1(b)(1)(ii)(F);

(g)

o

A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);

(h)

o

A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);

(i)

o

A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);

(j)

o

Group, in accordance with §240.13d-1(b)(1)(ii)(J).

Item 3 is not applicable.

Item 4.

Ownership

Provide the following information regarding the aggregate number and percentage of the class of securities of the issuer identified in Item 1.

(a)

Amount beneficially owned:   

1,986,740 shares

(b)

Percent of class:   

14.8 %

(c)

Number of shares as to which the person has:

(i)

Sole power to vote or to direct the vote   

1,986,740 shares

(ii)

Shared power to vote or to direct the vote    

None

(iii)

Sole power to dispose or to direct the disposition of   

1,986,740 shares

(iv)

Shared power to dispose or to direct the disposition of   

None

Item 5.

Ownership of Five Percent or Less of a Class

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following   o.

Item 5 is not applicable.

Item 6.

Ownership of More than Five Percent on Behalf of Another Person

Item 6 is not applicable.

Item 7.

Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company or Control Person

Item 7 is not applicable.

Item 8.

Identification and Classification of Members of the Group

Item 8 is not applicable.

Item 9.

Notice of Dissolution of Group

Item 9 is not applicable.

Item 10.

Certification

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

 SANOFI-AVENTIS

Date: February 13, 2007

By:

/s/ Jean-Claude Leroy

  Jean-Claude LEROY

  Executive Vice President

  Chief Financial Officer