Chiesi agreed to acquire KalVista Pharmaceuticals for about $1.9 billion in what it described as its biggest M&A deal yet, adding the FDA-approved hereditary angioedema therapy Ekterly (sebetralstat). The transaction values KalVista at $27 per share, a roughly 40% premium. Ekterly is an oral, on-demand plasma kallikrein inhibitor approved in July 2025, with expansion efforts underway across jurisdictions including the EU, U.K., and Japan. Chiesi framed the move as adding a commercialized rare disease asset rather than a purely pipeline bet. For the HAE market, the deal signals continued competition around route-of-administration advantages and sustained patient access after regulatory approval. For acquirers, it also reflects a preference for scaling marketed products with a known commercial ramp rather than early-stage risks. The next milestones will include closing mechanics and integration plans, especially around market access, manufacturing scale, and post-market pharmacovigilance.