Alexion in €639m bid for Wilson Therapeutics AB

Alexion’s offer represents a 70% premium compared to the closing share price on the last trading day prior to announcement of its offer and a 373% premium compared to the Initial Public Offering (IPO) price of the Wilson Therapeutics share of SEK 49.00 on May 12, 2016.

Wilson Therapeutics is a one product company that is in Phase III testing of WTX101, a first in class selective agent (tetrathiomolybdate) that stably complexes copper with proteins and restores the natural biliary excretion of excess copper. The drug candidate has US and EU orphan drug status and FDA fast track status, to treat Wilson’s disease, an autosomal recessively inherited defect of the ATP7B gene that triggers copper accumulation in the brain and liver leading to serious hepatic, neurologic or psychiatric symptoms. If approved, WTX101 could become an alternative to current therapy regimes that aim to reduce the cell-toxic copper accumulation using more or less unselective, adverse-effect-prone chelating agents for bivalent cations, copper-free diet, or zinc actetate, which stimulates metallothionein, a protein in gut cells that binds copper and prevents its absorption and transport to the liver. The complexes formed by existing therapies are often unstable and mostly excreted via the renal route.

Phase II data of WTX101 suggest that bis-choline tetrathiomolybdate can rapidly lower and control toxic free copper levels and improve clinical symptoms in Wilson’s disease patients. The data also suggest that it is generally well-tolerated with the potential for a reduced risk of neurological worsening after initiation of therapy compared to existing therapies. 

For Alexion, the take-over would secure a long-term financial revenue stream because potentially competing approaches such an AAV-based gene therapy developed by French Vivet Therapeutics are currently in preclinical development stage. Furthermore, Wilson has also received US orphan drug status for WTX101 as a treatment for Amyotrophic Lateral Sclerosis (ALS).