IDMI Idm Pharma (MM)

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE TO

(Rule 14d-100)

Tender Offer Statement under Section 14(d)(1) or 13(e)(1) 
of the Securities Exchange Act of 1934

(Amendment No.  5)

IDM PHARMA, INC.

(Name of Subject Company (Issuer))

TAKEDA PHARMACEUTICAL COMPANY LIMITED

TAKEDA AMERICA HOLDINGS, INC.

JADE SUBSIDIARY CORPORATION

(Names of Filing Persons (Offerors))

Common Stock, par value $0.01

(Title of Class of Securities)

449394105

(CUSIP Number of Class of Securities)

Laurie B. Keating

Takeda America Holdings, Inc.

40 Landsdowne Street

Cambridge, MA 02139

(617) 679-7000

 (Name, Address and Telephone Number of Person Authorized to Receive

Notices and Communications on Behalf of Filing Persons)

with copies to:

David E. Redlick

Graham Robinson

Wilmer Cutler Pickering Hale and Dorr LLP

60 State Street

Boston, Massachusetts 02109

(617) 526-6000

CALCULATION OF FILING FEE

*                  Estimated for purposes of calculating the amount of the filing fee only, in accordance with Rule 0-11(d) under the U.S. Securities Exchange Act of 1934, as amended (the “Exchange Act”).  The transaction valuation was calculated by multiplying (a) the closing cash payment of $2.64 per share by (b) the number of shares of common stock, par value $0.01 per share (“Shares”), of IDM Pharma, Inc. (“IDM”) outstanding on a fully diluted basis as of May 18, 2009 as represented by IDM, consisting of (x) 25,278,599 Shares issued and outstanding, (y) 1,378,023 Shares issuable upon exercise of outstanding options and (z) 3,377,412 Shares issuable upon exercise of outstanding warrants.

**           The amount of the filing fee was calculated in accordance with Rule 0-11(d) of the Exchange Act by multiplying the transaction valuation by 0.0000558.

x           Check the box if any part of the fee is offset as provided by Rule 0-11(a)(2) and identify the filing with which the offsetting fee was previously paid. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.

o   Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer.

Check the appropriate boxes below to designate any transactions to which the statement relates:

Check the following box if the filing is a final amendment reporting the results of the tender offer:   x

If applicable, check the appropriate box(es) below to designate the appropriate rule provision(s) relied upon:

This Amendment No. 5 (“Amendment No. 5”) amends and supplements the Tender Offer Statement on Schedule TO (the “Schedule TO”) originally filed with the U.S. Securities and Exchange Commission (“SEC”) on May 26, 2009, as amended and supplemented by Amendment No. 1 filed with the SEC on May 29, 2009 (“Amendment No. 1”), Amendment No. 2 filed with the SEC on June 2, 2009 (“Amendment No. 2”), Amendment No. 3 filed with the SEC on June 19, 2009 (“Amendment No. 3”), and Amendment No. 4 filed with the SEC on June 19, 2009 (“Amendment No. 4”), by Jade Subsidiary Corporation (“Offeror”), a Delaware corporation and wholly owned subsidiary of Takeda America Holdings, Inc. (“Takeda America”), which is a New York corporation and wholly owned subsidiary of Takeda Pharmaceutical Company Limited (“TPC”), a corporation organized under the laws of Japan, relating to the offer by Offeror to purchase all of the outstanding shares of common stock, par value $0.01 per share (the “Shares”), of IDM Pharma, Inc., a Delaware corporation (“IDM”), at a price of $2.64 per Share, net to the seller in cash (the “Offer Price”), upon the terms and subject to the conditions set forth in the Offer to Purchase dated May 26, 2009 (the “Offer to Purchase”) and in the related Letter of Transmittal (together with the Offer to Purchase, the “Offer”).  All references to the Offer to Purchase, the Letter of Transmittal and the Offer include any amendments or supplements to the Offer to Purchase and the Letter of Transmittal, respectively.  Takeda America and TPC may be deemed to share with the Offeror voting and investment control over Shares taken up in the Offer. The Offer Price will be subject to any required withholding of taxes, and no interest will be paid thereon.  Offeror expects to pay the Offer Price through Takeda America working capital. The Offer is made pursuant to an Agreement and Plan of Merger, dated as of May 18, 2009 (the “Merger Agreement”), among Takeda America, Offeror and IDM. Copies of the Offer to Purchase and the related Letter of Transmittal are filed as Exhibits (a)(1)(A) and (a)(1)(B), respectively, to the Schedule TO.

All references to the Schedule TO mean the Schedule TO, as amended by Amendment No. 1, Amendment No. 2, Amendment No. 3 and Amendment No. 4.  All capitalized terms used in this Amendment No. 5 without definition have the meanings ascribed to them in the Schedule TO or the Offer to Purchase.

The information in the Offer to Purchase and the related Letter of Transmittal is incorporated in this Amendment No. 5 by reference to all of the applicable items in the Schedule TO, except that such information is amended and supplemented to the extent specifically provided in this Amendment No. 5.

Items 1 through 9 and Item 11.

Items 1 through 9 and Item 11 of the Schedule TO are hereby amended and supplemented by adding the following text thereto:

“The initial offering period of the Offer expired at 12:00 midnight, New York City time, at the end of Monday, June 22, 2009.  According to American Stock Transfer & Trust Company, the depositary for the Offer, as of such time, a total of approximately 21,842,929 Shares (including Shares tendered under guaranteed delivery procedures) had been validly tendered pursuant to the Offer and not properly withdrawn, representing approximately 86.4% of all outstanding Shares.  Pursuant to the terms of the Offer, Offeror has accepted for payment all of such Shares.  Payment for such Shares will be made promptly in accordance with the terms of the Offer.

On June 23, 2009, TPC issued a press release announcing the completion of the initial offering period of the Offer.  TPC also announced that Offeror expects to exercise promptly the option granted to it in the Merger Agreement to purchase additional Shares at US$2.64 per Share, which will result in Jade owning more than 90% of the outstanding Shares.

Offeror expects to acquire any remaining outstanding Shares by means of a Merger of Offeror with and into IDM, as a result of which IDM will become a wholly owned subsidiary of Takeda America.  Pursuant to the Merger, each remaining outstanding Share (other than (1) any Shares held by IDM as treasury stock or owned by Takeda America, Offeror or any subsidiary of IDM, Takeda America or Offeror and (2) any Shares held by a holder who has not voted in favor of or consented to the Merger and who has properly demanded and perfected his, her or its right to be paid the fair value of such Shares in accordance with the provisions of Section 262 of the General Corporation Law of the State of Delaware) will be automatically cancelled and converted into the right to receive the Offer Price.  Takeda America expects to complete the Merger as soon as practicable pursuant to the short-form merger procedure available under the General Corporation Law of the State of Delaware.

The full text of the press release issued by TPC is attached hereto as Exhibit (a)(5)(J) and is incorporated herein by reference.”

2

Item 12 of the Schedule TO is hereby amended and supplemented by adding the following exhibit:

3

SIGNATURE

After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Dated: June 23, 2009

4

EXHIBIT INDEX

5

* Previously filed.

6

Schedule 1

POWER OF ATTORNEY

KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature appears below hereby constitutes and appoints Laurie Bartlett Keating and Jeannette Potts, and each of them, its true and lawful attorneys-in-fact and agents with full power of substitution and resubstitution, for it and in its name, place, and stead, in any and all capacities, to sign any and all filings, with all exhibits thereto, and other documents in connection therewith, with the Securities and Exchange Commission relating to the tender offer for shares of common stock of IDM Pharma, Inc. or subsequent merger of Jade Subsidiary Corporation with IDM Pharma, Inc., and hereby grants to each such attorneys-in-fact and agents full power and authority to do and perform each and every act and thing requisite and necessary to be done, as fully to all intents and purposes as he or she might or could do in person, hereby ratifying and confirming all that said attorneys-in-fact and agents or her substitute or substitutes may lawfully do or cause to be done by virtue hereof.

Dated: May 28, 2009