Singapore: Alexion pharmaceuticals recently announced the acquisition of Synageva Biopharma for $8.4 billion. US-based Synageva is a biopharmaceutical company dedicated to discovering, developing and delivering medicines for patients with rare diseases and high unmet medical needs.

The companies' combined developmental pipelines would give Alexion eight experimental medicines in clinical trials for 11 diseases, the company said. That includes Synageva's Kanuma, which is awaiting US and European approval to treat a rare and potentially fatal condition that causes a build-up of fat in the blood and liver.

The deal highlights the attraction of rare disease treatments that can command exceptionally higher prices. Alexion CEO Mr David Hallal expressed confidence that Kanuma sales will eventually exceed $1 billion.

The deal is the latest in a string of M&A s in the health care sector this year. Recent deals involving rare disease companies include Teva Pharmaceutical's $3.5 billion purchase of Auspex Pharmaceuticals in March and Shire's acquisition of NPS Pharmaceuticals for $5.2 billion in January.