5 November 2021 - - US-based biopharmaceutical company Astria Therapeutics, Inc. (NASDAQ: ATXS) has presented new preclinical data that included demonstration of the high potency of STAR-0215 to bind to and inhibit plasma kallikrein on a site different than lanadelumab and introduction of YTE technology to extend half-life.

The poster entitled "STAR-0215 is a Long-Acting Monoclonal Antibody Plasma Kallikrein Inhibitor for the Potential Treatment of HAE" was presented at the 2021 American College of Allergy, Asthma and Immunology Annual Scientific Meeting in New Orleans, Louisiana.

HAE is a rare genetic disorder characterized by severe, recurrent, unpredictable, painful, and sometimes life-threatening swelling in the face, limbs, abdomen, and airway.

Plasma kallikrein binding affinity and plasma half-life are key drivers of efficacy for the prevention of HAE attacks.

According to the company, the data presented show that STAR-0215 binds to plasma kallikrein in vitro with high affinity, about ten-fold more potently than lanadelumab, a monoclonal antibody plasma kallikrein inhibitor.

In addition, in competition binding experiments, STAR-0215 was shown to bind to a different site on plasma kallikrein than lanadelumab.

YTE modifications in STAR-0215 are designed to enable a longer duration of action. In cynomolgus monkeys dosed with STAR-0215, the enhanced FcRn binding enabled by the YTE modifications translated to a more than three-fold increase in plasma half-life to about 34 days with STAR-0215 compared to an antibody without the YTE modifications.

The plasma half-life of STAR-0215 in cynomolgus monkeys was also more than three-fold longer than that of lanadelumab, supporting the potential for less frequent dosing.

STAR-0215's potency was also tested using a physiologically relevant assay. STAR-0215 potently inhibited the release of bradykinin from high molecular weight kininogen, with an IC90 about 10-fold more potent than the IC90 achieved by lanadelumab in the same assay.

IC90 corresponds to the concentration required to inhibit 90% of enzymatic activity, which is thought to be the level of plasma kallikrein inhibition required to prevent HAE attacks.

Pharmacokinetic/pharmacodynamic modeling showed that STAR-0215 is predicted to prevent HAE attacks for a substantially longer period than lanadelumab.

Based on these data, STAR-0215 has the potential to be administered once every three months or longer to effectively prevent HAE attacks.

STAR-0215 is in preclinical development to treat HAE, and is a monoclonal antibody inhibitor of plasma kallikrein, designed to provide long-acting, effective HAE attack prevention.

The company's goal is to provide the most patient-friendly preventative treatment option for people living with HAE.

The company expects to file an Investigational New Drug application for STAR-0215 in mid-2022 and plans to initiate a Phase 1 clinical trial with initial results anticipated by year end 2022.

Astria Therapeutics is a biopharmaceutical company, whose lead program, STAR-0215, is a monoclonal antibody inhibitor of plasma kallikrein in preclinical development for the treatment of hereditary angioedema.