Shire’s decision to buy rare disease specialist NPS Pharmaceuticals for approximately US$5.2 B ahead of a regulatory decision on the company’s hypoparathyroidism therapy Natpara® (parathyroid hormone) has been vindicated. Less than 2 weeks after the deal was announced, Natpara was approved by the US FDA with a label deemed favourable by Shire. The acquisition is Shire’s largest to date and comes less than 3 months after AbbVie reneged on a £32 B (US$54.8 B) takeover bid for the company.