Biocryst to acquire Astria, getting experimental navenibart for HAE
Long-acting preventive treatment still being tested in clinical trials
Biocryst Pharmaceuticals is preparing to acquire Astria Therapeutics, and with it navenibart, a still-experimental, long-acting prophylactic (preventive) treatment that could improve care for people with hereditary angioedema (HAE) by reducing how often patients need injections.
Navenibart is now in Phase 3 clinical testing, after earlier data showed it was well-tolerated and able to prevent swelling attacks in adults with HAE. The treatment candidate was found to offer sustained benefits when injected subcutaneously, or under the skin, once or twice over six months in earlier studies.
The ongoing ALPHA-ORBIT trial (NCT06842823), underway at 29 locations worldwide, is recruiting patients as young as 12.
Both sides expressed satisfaction with the deal.
“We are thrilled to have navenibart become an integral part of Biocryst’s HAE portfolio, advancing our shared mission of empowering patients to live beyond the limitations of their disease,” Jill C. Milne, PhD, Astria’s CEO, said in a joint press release from the two companies.
Biocryst already has experience in HAE with Orladeyo (berotralstat), its oral treatment that’s approved to prevent swelling attacks in adults and adolescents ages 12 and older. The company recently licensed the European rights to Orladeyo to an Italian company.
According to Jon Stonehouse, Biocryst’s CEO, the acquisition gives the company “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.”
HAE is a type of angioedema caused by genetic mutations that lead to a deficiency in a protein called C1 inhibitor. Without C1 inhibitor, an enzyme called kallikrein becomes overactive and triggers the release of bradykinin. High levels of bradykinin cause blood vessels to leak fluid into tissues, making them swell.
Navenibart designed to require less-frequent dosing
Navenibart, an antibody designed to block kallikrein, is expected to lower bradykinin levels, thus preventing HAE swelling attacks. Unlike most other injectable treatments, which require frequent doses, navenibart may be injected only once every three to six months. According to its developer, the less frequent dosing can ease the burden of treatmend for people with HAE.
Top-line data from ALPHA-ORBIT, which aims to recruit 145 patients with HAE type 1 or 2, are expected in early 2027. The trial is testing how safe navenibart is compared with a placebo when injected at a dose of 300 or 600 mg every three or six months. It’s also assessing how well the therapy works to prevent swelling attacks over the six months of the study.
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.
If these data are positive and navenibart wins regulatory approval, it could serve an estimated 5,000 patients who currently receive injectable prophylaxis and who may prefer a longer-acting treatment option that reduces the burden of frequent injections, according to the companies.
“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,” Stonehouse said.
With its two products, Stonehouse expects to “be well-positioned to drive sustainable growth and profitability while optimally serving the HAE patient community.”
Biocryst will acquire Astria for about $700 million, paid in cash and shares, in a transaction expected to close in early 2026. After the transaction, Milne will join Biocryst’s board of directors. In addition to navenibart, Biocryst will acquire Astria’s program for atopic dermatitis, an inflammatory skin condition that causes itching.
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