$8.4bn deal gives firm access to enzyme drug currently under review with US and EU regulators

Rare disease drugmaker Alexion has agreed to buy US biotech Synageva for $8.4 billion (£5.4 billion) in a mix of cash and shares. The deal gives Alexion access to Synageva’s developmental enzyme-replacement drug for lysosomal acid lipase deficiency, Kanuma (sebelipase alfa), as well as some earlier stage projects.

Alexion specialises in biological drugs for ultra-rare conditions. The firm says that Kanuma, which is currently under review by regulators in the US and EU, will complement its other drugs. These include Soliris (eculizumab) – a monoclonal antibody approved for treating two rare auto-immune diseases, and Strensiq (asfotase alfa) – a metabolic enzyme-replacement that is being reviewed by regulators as a treatment for hypophosphatasia.

The deal also brings Synageva’s extra capacity and expertise in biological drug manufacturing.