28 February 2023 - - US-based biopharmaceutical company Astria Therapeutics, Inc. (NASDAQ: ATXS) presented new STAR-0215 data in two poster presentations at the American Academy of Allergy, Asthma, and Immunology annual meeting in San Antonio, Texas that demonstrate early proof-of-concept for STAR-0215's profile as a long-acting preventative therapy for HAE, the company said.

In a poster titled, "Initial Results from a Phase 1a Single Ascending Dose Clinical Trial of STAR-0215, an Investigational Long-Acting Monoclonal Antibody Plasma Kallikrein Inhibitor for Hereditary Angioedema, in Healthy Subjects Followed for at Least 3 Months," Chris Morabito, M.D., Chief Medical Officer at Astria Therapeutics, shared clinical data including unblinded safety data that showed that STAR-0215 was well-tolerated, with no serious adverse events or discontinuations due to an adverse event.

Additionally, there were no clinically significant changes in laboratory assessments, and there were no treatment-emergent anti-drug antibodies detected.

STAR-0215 demonstrated dose-dependent pharmacokinetics, with an estimated half-life of up to 117 days.

At Day 84, mean concentrations remained above the threshold for potential efficacy after a single 300 mg subcutaneous dose. Suppression of cleaved high molecular weight kininogen (cHMWK) to levels consistent with robust plasma kallikrein inhibition was achieved through Day 84 in both Western Blot and Chromogenic assays.

These results demonstrate early proof of concept for STAR-0215 as a potential long-acting therapy for HAE, and additional cohorts have been added to the Phase 1a trial to assess the potential for once every six-months administration, with preliminary results expected in the fourth quarter of 2023.

A second poster titled, "Structure of STAR-0215 Bound to Active Plasma Kallikrein Reveals a Novel Mechanism of Enzyme Inhibition" was presented by Nikolaos Biris, Ph.D., director of Assay Development at Astria Therapeutics, where STAR-0215 was shown to bind allosterically to a site that is unique to plasma kallikrein.

This allosteric binding of STAR-0215 blocks the formation of the active site of plasma kallikrein to potentially inhibit its activity and gives rise to the high selectivity for plasma kallikrein compared with prekallikrein and related serine proteases.

These findings, together with the additional Phase 1a clinical data that established long half-life in healthy subjects, support that STAR-0215 is a potential best-in-class therapy for the prevention of HAE attacks.

STAR-0215 is a monoclonal antibody inhibitor of plasma kallikrein in development for the treatment of HAE. Initial results from a Phase 1a trial in healthy subjects support STAR-0215's target profile: a long-acting preventative therapy, best-in-class PK profile, and dosing once every three months or less frequently.

The Phase 1b/2 ALPHA-STAR trial evaluating STAR-0215 in people living with HAE is ongoing, with initial results from single and multiple dose cohorts expected in mid-2024.

Astria Therapeutics is a biopharmaceutical company, and our mission is to bring life-changing therapies to patients and families affected by rare and niche allergic and immunological diseases.

Its lead program, STAR-0215, is a monoclonal antibody inhibitor of plasma kallikrein in clinical development for the treatment of hereditary angioedema.