Icatibant is a selective antagonist of the bradykinin type 2 receptor. In the randomized, double-blind, multicentre, FAST-1 trial, the difference in the median time to the onset of symptom relief (primary endpoint) did not reach statistical significance between a single dose of subcutaneous icatibant 30 mg and placebo in adults with moderate to very severe acute abdominal or cutaneous episodes of hereditary angioedema. However, icatibant was effective with regard to several other endpoints, providing significantly greater reductions from baseline in symptom severity scores 4 and 12 hours after administration, and eliciting significantly shorter times to both first symptom improvement and overall patient improvement than placebo. In the similarly designed, active comparator-controlled, FAST-2 trial, a single dose of subcutaneous icatibant 30 mg was associated with a significantly shorter median time to onset of symptom relief (primary endpoint) than oral tranexamic acid in adults with acute abdominal or cutaneous episodes of hereditary angioedema, and was also more effective than tranexamic acid in terms of most other endpoints. Across both FAST-1 and -2, the efficacy of subcutaneous icatibant 30 mg in the treatment of laryngeal episodes of hereditary angioedema was generally consistent with that seen for abdominal and cutaneous episodes, with a median time to first symptom improvement of 0.6-1.0 hours. Subcutaneous icatibant was generally well tolerated in adult patients with hereditary angioedema in the FAST trials, with the most common adverse events being injection-site reactions that were generally of mild severity, transient in nature and resolved spontaneously without treatment.