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

BioCryst Pharmaceuticals has announced its acquisition of Astria Therapeutics for $700 million, positioning itself to enhance its offerings in the hereditary angioedema (HAE) market. This strategic move aims to provide patients with a less frequent dosing option for preventing swelling attacks associated with this rare disease.

Patients currently rely on injectable medications that require administration every two weeks to every two months. The acquisition of Astria, which is developing an injectable kallikrein inhibitor named navenibart, could potentially reduce this to as few as two injections per year. BioCryst, based in Durham, North Carolina, already markets Orladeyo, a once-daily oral medication designed to prevent HAE attacks by blocking the kallikrein protein involved in swelling.

Details of the Acquisition and Clinical Trials

Astria Therapeutics, located in Boston, is currently conducting a global Phase 3 clinical trial for navenibart. This trial includes various dosing regimens, testing an initial dose of 600 mg followed by 300 mg every three months, 600 mg every six months, or another 600 mg every three months. The primary goal is to measure the number of HAE attacks over a six-month treatment period, with preliminary results expected by early 2027.

BioCryst’s portfolio is heavily invested in HAE treatments, particularly with Orladeyo, which generated $437.6 million in sales last year. Anticipated FDA decisions regarding an oral granule formulation of Orladeyo for children aged 2 to 11 are expected by December 12, 2023.

As competition intensifies in the HAE therapy market, BioCryst faces significant rivals, including Takeda Pharmaceutical, which has the leading drug, Takhzyro, an FDA-approved kallikrein inhibitor requiring injections every two weeks. Recent approvals for two new HAE drugs have further diversified patient options. CSL Behring launched Andembry in June, a monthly injection, followed by Ionis Pharmaceuticals with Dawnzera, an antisense oligonucleotide administered monthly or bi-monthly.

BioCryst’s acquisition of Astria could position navenibart as a leading therapy option, offering a three- to six-month injection schedule that may enhance patient adherence and reduce injection site pain.

Market Dynamics and Future Projections

During an investor call on October 14, 2023, BioCryst’s Chief Commercial Officer, Charlie Gayer, emphasized the growing demand for less burdensome dosing options among HAE patients. “The market isn’t looking for more efficacy; what it’s looking for is less burdensome dosing,” he stated.

BioCryst projects that its HAE portfolio, driven by Orladeyo and the potential success of navenibart, could generate up to $1 billion in revenue by 2029 and exceed $1.8 billion by 2033. The company continues to explore other rare disease treatments, including BCX17725, an early-stage protein drug for Netherton syndrome, which currently lacks FDA-approved therapies.

The terms of the acquisition include $8.55 in cash and 0.58 shares of BioCryst common stock per Astria share, valuing the latter’s shares at approximately $13, a 53% premium over its pre-announcement closing price. To support the cash requirements, BioCryst has secured up to $550 million in debt financing managed by Blackstone.

Pending necessary approvals from regulatory bodies and Astria shareholders, the transaction is expected to close in the first quarter of 2026. Following the merger, Astria’s CEO, Jill Milne, will join the BioCryst board, and Astria’s shareholders will hold around 15% of the combined entity.

BioCryst’s acquisition of Astria not only strengthens its position in the HAE market but also highlights its commitment to expanding its product offerings for rare diseases.