Celgene Corp has signed a deal with partner Acetylon Pharmaceuticals giving it an option to buy the epigenetic specialist in a deal that could be worth over $1.70 billion.

Their latest collaboration will focus on the continued advancement of Acetylon’s lead candidate, ACY-1215, an oral first-in-class selective HDAC6 inhibitor for haematological malignancies, ACY-738 for neurological diseases, an HDAC1/2 inhibitor, and a yet unnamed project, spanning cancer and non-cancer disease indications. Under the terms of the agreement, Acetylon will receive a $100 million upfront cash payment.

In return, Celgene receives an exclusive option to acquire Acetylon and if it decides to proceed, a further upfront payment of a minimum of $500 million will be paid at the time of closing. Additionally, Acetylon shareholders will be eligible to receive $1.10 billion, comprised of $250 million for regulatory and $850 million for sales milestones.

Acetylon chief executive Walter Ogier says Celgene has been "an enthusiastic investor and supporter…since completing its equity investment in our company early last year". He added that the $100 million upfront fee "should enable us to aggressively advance our drug pipeline and create substantial value".

Array BioPharma pact

Meantime, Celgene has also signed a deal with Array BioPharma for a preclinical development programme targeting a novel inflammation pathway.

Array will receive an upfront payment of $11 million and Celgene will have an exclusive option to license multiple clinical development candidates. Array is entitled to receive potential milestone payments of up to $376 million, plus royalties.