Shire is developing lanadelumab (Takhzyro™) for the prevention of hereditary angioedema (HAE) attacks. Lanadelumab is a fully human monoclonal antibody that inhibits plasma kallikrein. Mutations in the SERPING1 gene lead to C1 inhibitor deficiency or dysfunction, resulting in uncontrolled plasma kallikrein activity, which in turn produces excessive bradykinin, a vasodilator thought to cause angioedema symptoms. Subcutaneous administration of lanadelumab significantly reduced HAE attacks versus placebo in patients aged ≥ 12 years with type I or II HAE in a phase III trial. Based on these results, lanadelumab is recently approved in the USA for the prevention of HAE attacks in patients aged ≥ 12 years. It is also preregistered in the EU, Canada, Australia and Switzerland. This article summarizes the milestones in the development of lanadelumab leading to this first approval.