H. Lundbeck has agreed to buy Chelsea Therapeutics for US$530 M upfront in order to add the orphan drug Northera™ (droxidopa) to its US neurology portfolio. After previously being rejected by the US FDA, Northera was granted accelerated approval in February 2014 for the treatment of symptomatic neurogenic orthostatic hypotension. Chelsea shareholders will also receive contingent value rights that could pay up to US$1.50 per share dependent on sales levels of Northera in the period 2015-2017, bringing the potential total deal value to US$658 M.