BioCryst Pharmaceuticals has signed a definitive agreement to buy Astria Therapeutics with a mix of cash and stock transactions. The deal values Astria at an implied $13 per share, culminating in an enterprise value of around $700m.

The companies’ boards of directors have unanimously approved the acquisition and the transaction will be finalised in the first quarter of 2026.

Upon completion, Astria CEO Jill Milne will join the BioCryst board of directors.

The acquisition is expected to provide strategic benefits by expanding BioCryst's portfolio with a late-stage, rare disease product candidate.

Astria's flagship candidate, navenibart, is an injectable monoclonal antibody inhibitor targeting plasma kallikrein for the prophylaxis of hereditary angioedema (HAE).

Navenibart is in Phase III clinical development, with expectations of improvements over current treatment options due to its extended administration schedule of every three to six months.

BioCryst's commercialisation infrastructure and knowledge in HAE will enhance the distribution of the antibody.

BioCryst will also acquire Astria's early-stage atopic dermatitis programme, STAR-0310, and is considering strategic options for this asset.

BioCryst has also secured a debt commitment letter from Blackstone-managed funds for a strategic financing facility of up to $550m.

The cash portion of the acquisition is expected to be financed through BioCryst’s available cash and a part of the Blackstone facility.

Based on basic shares outstanding, the stockholders of Astria are projected to own almost 15% of the proforma equity in the merged entity.

BofA Securities and Covington & Burling are advising BioCryst, while Evercore and Sidley Austin are advising Astria on the transaction.

BioCryst CEO Jon Stonehouse stated: “We believe this transaction gives BioCryst a perfect second product candidate that fits seamlessly with our HAE core competency and enables us to build out a comprehensive portfolio that could offer the most patient-friendly option, regardless of administration preference.

“Navenibart can emerge as the injectable of choice for patients seeking infrequent, pain-free dosing, strong attack control and a mechanism of action they know and understand.”

In May 2025, the US Food and Drug Administration (FDA) granted priority review to BioCryst’s new drug application for Orladeyo (berotralstat) for use in children aged two to 11 with HAE.