BioCryst Acquires Astria for $700M to Compete in HAE Market

BioCryst Pharmaceuticals has announced its acquisition of Astria Therapeutics for $700 million, a strategic move aimed at enhancing its position in the competitive market for hereditary angioedema (HAE) treatments. This acquisition could provide patients with a less frequent dosing option for managing HAE, a rare disease that leads to severe swelling attacks.

Currently, patients manage HAE with injectable drugs that require administration every two weeks to two months. BioCryst aims to transform this landscape with Astria’s lead asset, navenibart, which could potentially reduce the need for injections to as few as two times a year. Based in Durham, North Carolina, BioCryst is already a key player in the HAE market, marketing Orladeyo, a once-daily oral medication approved for preventing HAE attacks.

The acquisition of Astria Therapeutics, which is based in Boston, grants BioCryst access to navenibart, an injectable kallikrein inhibitor designed for selective targeting and a long half-life. This allows for less frequent dosing. Earlier this year, Astria commenced a global Phase 3 clinical trial to evaluate navenibart’s efficacy, with preliminary results expected in early 2027. The trial includes various dosing regimens, including 600 mg every three months and 600 mg every six months, with the primary goal of measuring the number of HAE attacks during a six-month treatment period.

BioCryst’s emphasis on HAE is underscored by its commercial success with Orladeyo, which generated $437.6 million in sales last year. The company anticipates that revenue from Orladeyo will reach $550 million by 2025. An FDA decision is also expected by December 12 regarding an oral granule formulation of Orladeyo for children aged 2 to 11.

The HAE treatment market is increasingly competitive, with Takeda Pharmaceutical leading with its product Takhzyro. Approved in 2018, Takhzyro is administered as a subcutaneous injection every two weeks, though some patients may extend the dosing to every four weeks. Recently, two new therapies for HAE prophylaxis received FDA approval, providing additional options for patients. CSL Behring’s Andembry was approved in June and is designed to block factor XIIa, requiring monthly injections. In August, Ionis Pharmaceuticals gained approval for Dawnzera, an antisense oligonucleotide that targets the messenger RNA responsible for pre-kallikrein, administered monthly or bi-monthly.

BioCryst’s acquisition of Astria could position navenibart as a leading injectable therapy, with the potential for three- or six-month intervals for administration. Recent Phase 1b/2 trial results indicated an impressive average 92% reduction in HAE attacks, alongside a 50% attack-free rate. These outcomes surpass those of existing injectable therapies.

During an October 14 conference call, BioCryst Chief Commercial Officer Charlie Gayer highlighted the market’s need for less burdensome dosing rather than just increased efficacy. He noted, “The market isn’t looking for more efficacy; what it’s looking for is less burdensome dosing. That’s what navenibart has the potential to provide.”

The terms of the acquisition include $8.55 in cash and 0.58 shares of BioCryst common stock per share of Astria, valuing Astria’s shares at approximately $13 each, representing a 53% premium over the stock’s closing price prior to the announcement. Additionally, BioCryst has secured up to $550 million in debt financing from Blackstone, part of which will fund the cash component of the acquisition.

The transaction is subject to regulatory approvals and shareholder consent and is expected to close in the first quarter of 2026. Following the acquisition, Astria CEO Jill Milne will join BioCryst’s board, and Astria shareholders will hold about 15% of the combined company.

Alongside navenibart, Astria’s pipeline includes STAR-0310, an antibody aimed at blocking the inflammatory protein OX40, intended for atopic dermatitis treatment. BioCryst plans to explore strategic alternatives for this early-stage asset, given its focus on rare diseases.

As BioCryst continues to expand its portfolio, the company is optimistic about the future growth of its HAE treatments. With projected revenue from its HAE portfolio expected to reach $1 billion by 2029, and over $1.8 billion by 2033, the acquisition of Astria represents a significant step in its strategy to meet patient needs and stay competitive in the evolving market.