Shire plc / Dyax Corp.

Hereditary Angioedema (HAE)

$2.0B Forecast peak global lanadelumab annual sales at deal time (~$2B)

Disease Overview

Hereditary angioedema is a rare autosomal-dominant disorder, typically caused by C1-esterase inhibitor deficiency or dysfunction, that produces unpredictable, painful swelling attacks of the extremities, abdomen, face, and airway; laryngeal attacks can be fatal without intervention. Type 1 HAE accounts for ~80-85% of cases, Type 2 for 15-20%, and HAE with normal C1-INH for a small remaining fraction. Treatment had historically focused on rescue (icatibant, ecallantide, plasma-derived C1-INH) rather than long-term prophylaxis.

Competitive Landscape

At deal time (Nov-2015 announce / Jan-2016 close), Shire already owned the leading HAE rescue franchise — FIRAZYR (icatibant, bradykinin B2 antagonist) and CINRYZE (plasma-derived C1-INH prophylaxis IV every 3-4 days) — competing against CSL Behring's Berinert (acute pdC1-INH), Pharming's RUCONEST (recombinant C1-INH), and Dyax's own ecallantide (KALBITOR). The strategic gap Shire was filling was long-acting subcutaneous prophylaxis: DX-2930/lanadelumab is a fully human monoclonal antibody against plasma kallikrein dosed every 2-4 weeks subq, with Phase 1b data showing >90% attack reduction at 300/400 mg arms. FierceBiotech characterized the $5.9B price as 'a defensive rare disease deal' protecting CINRYZE from cannibalization while extending HAE category dominance. The Phase 3 HELP study readout in 2017 delivered an 87% attack-rate reduction at the 300mg q2w arm and the FDA approved Takhzyro in August 2018, validating the deal economics — GlobalData later flagged lanadelumab as the single most valuable asset in the Shire/Takeda portfolio by peak-sales forecast. Subsequent competitive entrants include CSL's HAEGARDA (subq pdC1-INH) and BioCryst's ORLADEYO (oral plasma kallikrein inhibitor, 2020), with KalVista's sebetralstat advancing as an oral on-demand option.