The Oral Revolution for Rare Disease Is Here

Chiesi acquires KalVista for $1.9 billion, securing the first oral on-demand treatment for hereditary angioedema and sidelining painful injections

5 May 2026

Chiesi Group, the Italian family-owned drugmaker, has agreed to acquire KalVista Pharmaceuticals for $1.9bn, gaining control of Ekterly, the first pill approved for the on-demand treatment of acute hereditary angioedema (HAE) attacks. Both companies' boards approved the deal unanimously on 29 April 2026, with completion expected in the third quarter.

HAE is a rare genetic condition that causes sudden and sometimes life-threatening swelling episodes. Until Ekterly's approval by the US Food and Drug Administration in July 2025, patients depended solely on injectable treatments during attacks. The drug, known generically as sebetralstat, captured close to 20 per cent of the US HAE market in its first year, generating $49.1m in product revenue. It has since received regulatory clearance in the European Union, United Kingdom, Switzerland, Australia, Singapore, and Japan.

At $27.00 per share, the transaction represents a 36 per cent premium to KalVista's recent trading price and the largest acquisition in Chiesi's 90-year history. The deal is central to Chiesi's ambition to reach €6bn in annual revenue by 2030. Its rare disease division posted €906m in revenue in fiscal 2025, a rise of 22 per cent year on year.

A filing to extend Ekterly's approved use to children aged 2 to 11 is planned for later this year, which could expand the drug's addressable market. The HAE treatment space is drawing wider competitive attention: Pharvaris is preparing a regulatory submission for a rival oral therapy, while Intellia Therapeutics is advancing a potential gene-editing treatment that could offer a one-time intervention. Analysts at RBC Capital Markets have suggested that the acquisition may prompt renewed interest in remaining independent HAE-focused companies from larger pharmaceutical buyers.

Whether Chiesi can sustain Ekterly's early commercial momentum as oral competition intensifies is the central question facing the combined business.