Cephalon, Inc. and ChemGenex Pharmaceuticals Limited jointly announced that Cephalon's wholly-owned subsidiary, Cephalon CXS Holdings Pty Ltd, intends to make a takeover bid for ChemGenex. ChemGenex is a haematology-focused Australian biopharmaceutical company developing its lead product candidate, Omapro, for the treatment of Chronic Myeloid Leukaemia (CML) patients. Omapro recently completed phase III clinical trials and ChemGenex plans to file a New Drug Application with the US Food and Drug Administration in the second half of 2011.

The takeover bid has the unanimous support of the ChemGenex directors who will recommend it to ChemGenex shareholders in the absence of a superior offer.

In October 2010, Cephalon, through its wholly-owned subsidiary, Cephalon International Holdings, Inc. (Cephalon International) agreed to subscribe for A$15 million of convertible notes issued by ChemGenex and entered into call option agreements with two of ChemGenex's major shareholders, Stragen International N V and Merck Sante S A S ChemGenex shareholders gave advance approval to the conversion of the convertible notes (in accordance with item 7 of section 611 of the Corporations Act) at a general meeting held in December 2010.

Cephalon International has today served notice to convert its convertible notes and exercise its call options to acquire in aggregate 86.4 million ChemGenex shares. This will result in Cephalon International holding in total 27.57 per cent of the issued ChemGenex shares.

Cephalon's takeover bid for ChemGenex will comprise two offers: an offer of A$0.70 cash for each ChemGenex Share, cum dividends and other rights; and an offer of A$0.02 cash for each ASX-listed ChemGenex Option.

Subject to obtaining advice on the applicable US law requirements, Cephalon will consider extending the share offer to holders of ChemGenex American Depository Receipts (ADRs) if compliance with those requirements is not unduly onerous or impracticable.

The offer price of A$0.70 per ChemGenex share represents: a 59 per cent premium to the last traded price of ChemGenex shares; a 58 per cent premium to the one month VWAP of ChemGenex shares up to the date of this announcement; a 31 per cent premium to the mid point of the valuation range of each ChemGenex Share of A$0.46 to A$0.61 on a controlling interest basis assessed by BDO Corporate Finance in its Independent Expert's Report (IER) of 15 November 2010, sent to ChemGenex shareholders in connection with the meeting material seeking their approval of the conversion of the convertible notes issued to Cephalon International. The IER was prepared to assist shareholders in considering a resolution to approve the conversion of the convertible notes in accordance with item 7 of section 611 of the Corporations Act; and a 40 percent premium to the A$0.50 conversion price of the convertible notes issued to Cephalon and approved by the ChemGenex shareholders last year.

“The proposed transaction allows ChemGenex shareholders to realize cash proceeds at a significant premium to recent trading levels and adds an interesting late-stage opportunity to our portfolio,” said Kevin Buchi, CEO of Cephalon.

“The ChemGenex Board welcomes Cephalon's bid which represents an attractive premium to the current and recent trading prices of ChemGenex Shares. In the absence of a superior offer, the Board will unanimously recommend that ChemGenex shareholders accept the offer and realize value for their shares,” said Brett Heading, chairman of ChemGenex.

The takeover offers for ChemGenex shares and listed ChemGenex options will each be subject to certain normal conditions (outlined in Appendices A, B and C), including a 90 percent minimum acceptance condition.

ChemGenex has informed Cephalon that each ChemGenex director with personal holdings of ChemGenex shares or listed ChemGenex options has confirmed that he intends to accept or procure the acceptance of the offers in respect of those ChemGenex shares or listed ChemGenex options, in the absence of a superior offer.

The total offer value for ChemGenex shares and listed ChemGenex options that Cephalon does not own is approximately A$159 million (US$163 million). The offer values all ChemGenex shares and options at approximately A$225 million (US$231 million). Cephalon intends to fund the transaction consideration from its available cash on hand.

Cephalon will finalize and mail out its Bidder's statement and ChemGenex will finalize and mail out its target's statement as soon as practicable. Holders of ChemGenex shares and listed ChemGenex options should carefully consider those documents before deciding whether to accept into the Cephalon takeover bid.

Cephalon is being advised by BofA Merrill Lynch and Johnson Winter & Slattery. ChemGenex is being advised by Canaccord Genuity and McCullough Robertson.

Cephalon is a global biopharmaceutical company dedicated to discovering, developing and bringing to market medications to improve the quality of life of individuals around the world.

ChemGenex is an oncology focused biopharmaceutical company developing small molecules with new mechanisms of action to treat malignancies with significant unmet medical needs.