Astria Therapeutics (ATXS) TD Cowen 45th Annual Healthcare Conference summary

Lead program and clinical results

• Navenibart, a monoclonal antibody plasma kallikrein inhibitor, is being developed for hereditary angioedema (HAE) prophylaxis, showing robust efficacy and safety in phase 1b/2 trials, with over 90% reduction in attack rates and up to 67% attack freedom rate.

• Both three-month and six-month dosing regimens demonstrated similar efficacy, supporting flexible patient dosing options.

• Phase III trial design incorporates both dosing regimens in a single pivotal study, now initiated, with top-line data expected in early 2027.

• Dose selection for phase III was data-driven, leveraging PK/PD and efficacy data, with 600 mg every six months and two three-month arms (600 mg/300 mg and 600 mg/600 mg) to address patient needs.

• Open-label extension (Orbit Expansion) allows patients to continue on their regimen or switch, providing long-term safety and efficacy data.

Market landscape and competitive positioning

• Market research with 50 US physicians indicated potential for 50% market share in both newly diagnosed and existing HAE patients on preventative therapy.

• Flexible dosing (Q3 and Q6 months) is seen as a major differentiator versus competitors, with strong KOL and patient enthusiasm.

• The HAE market is less sticky than previously thought, with patient-friendly regimens driving adoption, as seen with Orladeyo's uptake.

• Navenibart's trusted mechanism and rapid onset, combined with YTE technology for infrequent dosing, position it favorably against both current and future competitors, including gene therapies.

• Patent estate could provide exclusivity through 2042–2043, covering composition and dosing.

Pipeline and future catalysts

• STAR-310, an OX40 receptor antagonist for atopic dermatitis and other T cell-mediated diseases, incorporates learnings from prior programs to reduce adverse events and enable infrequent dosing.

• Phase I trial for STAR-310 began in January, with interim results expected in Q3, focusing on safety, PK, and dose selection.

• Multiple catalysts expected in the next 6–12 months, including long-term Navenibart data (Alpha Solar) and STAR-310 phase I results.

• Ongoing market and KOL feedback remains highly positive, with expectations for Navenibart to achieve significant commercial success.

• Management views the program as underappreciated, expecting phase III clarity to drive greater recognition.