In a bold move that strengthens its foothold in the rare disease and immunology market, BioCryst Pharmaceuticals Inc. announced Tuesday that it will acquire Astria Therapeutics Inc. in a cash-and-stock transaction valued at approximately $700 million.

The biopharmaceutical power play brings together BioCryst’s commercialization muscle and Astria’s innovative research pipeline, signaling a new era in therapies for hereditary angioedema (HAE) and allergic and immunologic disorders.

Under the agreement, BioCryst will purchase all outstanding Astria shares for $8.55 in cash plus 0.59 BioCryst shares, representing an implied value of about $13 per share — a 53% premium over Astria’s October 13 closing price. The announcement sent Astria’s stock soaring more than 40% by Tuesday afternoon.

When the deal closes, expected in the first quarter of 2026, Astria shareholders will own roughly 15% of the combined company. To fund the transaction, BioCryst secured a $550 million debt commitment from funds managed by Blackstone.

Navenibart: A Promising Frontier in HAE Treatment

At the heart of the acquisition lies Astria’s flagship therapy candidate, navenibart, an injectable antibody inhibitor designed to treat hereditary angioedema, a rare genetic disease marked by unpredictable and painful swelling attacks.

BioCryst, already established in the HAE market with its expertise and commercial infrastructure, sees navenibart as a next-generation breakthrough.

“Navenibart can emerge as the injectable of choice for patients seeking infrequent, pain-free dosing, strong attack control, and a trusted mechanism of action,” said Jon Stonehouse, CEO of BioCryst.

Upon completion, BioCryst will also acquire Astria’s early-stage program for atopic dermatitis, further broadening its immunology portfolio.

Leadership and Advisors Behind the Deal

Both companies’ boards have unanimously approved the transaction. Astria CEO Dr. Jill C. Milne will join BioCryst’s board of directors, bringing her scientific and leadership experience to the merged entity.

“We have great confidence in BioCryst’s proven expertise and ability to successfully bring navenibart to patients who need better options,” Milne said.

On the advisory front, Covington & Burling LLP is representing BioCryst, led by partners Jack Bodner and Andrew Ment, while Sidley Austin LLP is advising Astria through partners Rosemary Reilly, John Butler, and Sally Wagner Partin.

BofA Securities Inc. is serving as BioCryst’s exclusive financial adviser, with Evercore advising Astria. Sullivan & Cromwell LLP, led by partner Stephen M. Kotran, is advising Evercore.