Jazz Pharmaceuticals is the latest drugmaker to hit the acquisition trail with its proposed purchase of Eusa Pharma and its leukaemia therapy Erwinaze.

Jazz is initially paying out $650 million to buy privately-held Eusa, which has headquarters in the USA and the UK. The latter's owners are also in line for an extra $50 million milestone payable in cash based upon Erwinaze (asparaginase Erwinia chrysanthemi), achieving specified US sales target in 2013.

Erwinaze was approved by the US Food and Drug Administration last November for the treatment of acute lymphoblastic leukaemia (ALL) in patients with hypersensitivity to existing E coli-derived asparaginase. ALL is the most common form of childhood cancer, with 3.600 patients under the age of 20 diagnosed in the USA each year.

Jazz says the transaction is expected to be immediately accretive to earnings  upon closing in 2012 and in 2013 is expected to provide additional revenue of $210-$230 million, and $0.75 to $0.85 in adjusted earnings per share. Chief executive Bruce Cozadd added that the deal will "expand our global footprint and marketed product portfolio", which is presently led by the narcolepsy drug Xyrem (sodium oxybate) and severe pain treatment Prialt (ziconotide).