An investigation on behalf of current investors in IDM Pharma Inc. (NASDAQ: IDMI), who purchased their shares before Monday, May 18, 2009, over possible breach of fiduciary duty by the board of directors of IDM Pharma Inc. announced.

IDM Pharma announced that Japans Takeda Pharmaceutical Companys subsidiary, Takeda America Holdings, Inc., plans to acquire IDM Pharma for US$2.64 per share in an all cash tender offer followed by a merger. Under the terms of the agreement, the transaction has a value of approximately $66.7 million. According to the investigation by a law firm the investigation focuses on possible breaches of fiduciary duty and other violations of state law by the board of directors of IDM Pharma, Inc. (NASDAQ: IDMI) arising out of their attempt to sell IDM Pharma to Takeda Pharmaceutical Co. The transaction, so the investigation, is unfair, given that, among other things, shares of IDM Pharma (IDM) traded above $2.60 per share as recently as March 23, 2009 and above $3.40 per share as recently as September 22, 2008. The investigation raises also the concern that the process IDM Pharma conducted was flawed because owners of approximately 55% of the outstanding shares already agreed to tender their shares and IDM agreed to a non-solicitation provision that will all but ensure that no superior offer will ever be forthcoming.

IDM Pharma, Inc. is a biopharmaceutical company focused on the development of cancer products that either destroys cancer cells by activating the immune system or prevents tumor recurrence by triggering an adaptive immune response. IDM Pharma, Inc. is located in Irvine, California. The shares of IDM traded after the announcement at $2.62 per share, down from a 52weekHigh of $3.75 per share. In April 2007 IDM shares reached as high as $9.25 per share.