Astria Therapeutics Initiates ALPHA-ORBIT Phase 3 Pivotal Trial of Navenibart in Hereditary Angioedema

Astria Therapeutics, Inc. (Nasdaq:ATXS), a biopharmaceutical company focused on developing life-changing therapies for allergic and immunologic diseases, today announced the initiation of the ALPHA-ORBIT Phase 3 clinical trial of navenibart in people living with hereditary angioedema (HAE). Navenibart has the potential to provide rapid and sustained HAE attack prevention with a very low treatment burden and administration every 3 months (Q3M) and every 6 months (Q6M).

“We believe that navenibart will deliver strong efficacy, low treatment burden, and favorable safety and tolerability and we are thrilled to have initiated our Phase 3 ALPHA-ORBIT trial to support that vision,” said Christopher Morabito, M.D., Chief Medical Officer at Astria Therapeutics. “The Phase 3 program is designed to enable options, providing patients and physicians with the potential to decide what works best for them by administering navenibart only 2 or 4 times per year.”

“We understand from patients that it would be incredibly meaningful to have a therapy that would enable them to live their lives free from the limitations of HAE,” said Dr. Aleena Banerji, Clinical Director MGH Allergy and Immunology Unit, and a Principal Investigator for the ALPHA-ORBIT trial. “Navenibart has demonstrated the potential to prevent HAE attacks with infrequent dosing, which could allow patients the freedom to spend less time managing their disease.”

ALPHA-ORBIT is a global, randomized, double-blind, placebo-controlled Phase 3 pivotal clinical trial to evaluate the efficacy and safety of navenibart over a 6-month treatment period in up to 135 adults and 10 adolescents (open label), with HAE Type 1 or Type 2. Adult patients will be randomized to receive one of three navenibart dose arms: 1) an initial 600 mg dose followed by 300 mg Q3M, 2) 600 mg Q6M, 3) 600 mg Q3M, or placebo; adolescents will receive an initial 600 mg dose followed by 300 mg Q3M. The dose arms support the potential to provide patient-centered dosing flexibility to people with HAE. The primary endpoint is time-normalized monthly HAE attacks at 6 months, and a key secondary endpoint includes the proportion of participants who are attack-free at 6 months. Top-line results from the trial are anticipated in early 2027.

For more information on the ALPHA-ORBIT Phase 3 trial, please visit AlphaOrbit.longboat.com, astriatrials.com, or clinicaltrials.gov, NCT06842823.

After 6 months, patients may be eligible to enter a long-term trial, called ORBIT-EXPANSE, in which all patients will be treated with navenibart and which includes a patient-centered flexible dosing period. The navenibart Phase 3 program consists of the ALPHA-ORBIT Phase 3 trial and ORBIT-EXPANSE long-term trial, which are designed to support registration globally.

The Phase 3 program was designed based on positive final top-line results from target enrollment in the Phase 1b/2 ALPHA-STAR trial of navenibart, which showed rapid onset of robust and durable efficacy, favorable safety and tolerability, and pharmacokinetics and pharmacodynamics consistent with sustained plasma kallikrein inhibition for both Q3M and Q6M administration. Final results included reduction in mean monthly attack rate of 90-95% and up to a 67% attack-free rate over 6 months.

About Navenibart:

Navenibart is an investigational monoclonal antibody inhibitor of plasma kallikrein in Phase 3 development for the treatment of HAE. Our goal with navenibart is to provide rapid and sustained HAE attack prevention with a validated mechanism and trusted modality administered every 3 and 6 months. We aim to empower people with HAE to live without limitations from their disease.

About Astria Therapeutics:

Astria Therapeutics is a biopharmaceutical company, and our mission is to bring life-changing therapies to patients and families affected by allergic and immunologic diseases. Our lead program, navenibart (STAR-0215), is a monoclonal antibody inhibitor of plasma kallikrein in clinical development for the treatment of hereditary angioedema. Our second program, STAR-0310, is a monoclonal antibody OX40 antagonist in clinical development for the treatment of atopic dermatitis. Learn more about our company on our website, www.astriatx.com, or follow us on Instagram @AstriaTx and on Facebook and LinkedIn.

Forward Looking Statements:

This press release contains forward-looking statements within the meaning of applicable securities laws and regulations including, but not limited to, statements regarding: our expectations about the potential significance of the topline results from the target enrollment of the Phase 1b/2 ALPHA-STAR clinical trial of navenibart, including with respect to the selection of the dosing for the Phase 3 program; the expected timing of receipt of topline results from the ALPHA-ORBIT trial; the goals of the design of the navenibart Phase 3 program; our goal of developing two dosing options for navenibart and the potential advantages and benefits thereof; the potential for navenibart in the HAE market, including the potential to be the market leading treatment in HAE, the potential therapeutic and other benefits of navenibart as a treatment for HAE, and our vision and goals for the program; and the goal of bringing life changing therapies to patients and families affected by allergic and immunological diseases and to become a leading allergy and immunology company. The use of words such as, but not limited to, “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “goals,” “intend,” “may,” “might,” “plan,” “potential,” “predict,” “project,” “should,” “target,” “will,” “would,” or "vision," and similar words expressions are intended to identify forward-looking statements. Forward-looking statements are neither historical facts nor assurances of future performance. Instead, they are based on Astria’s current beliefs, expectations and assumptions regarding the future of its business, future plans and strategies, future financial performance, results of pre-clinical and clinical results of Astria’s product candidates and other future conditions. Actual results may differ materially from those indicated by such forward-looking statements as a result of various important factors, including the following risks and uncertainties: changes in applicable laws or regulations; the possibility that we may be adversely affected by other economic, business, and/or competitive factors; risks inherent in pharmaceutical research and development, such as: adverse results in our drug discovery, preclinical and clinical development activities, the risk that the results of preclinical studies, including of navenibart and STAR-0310, may not be replicated in clinical trials, that the preliminary or interim results from clinical trials may not be indicative of the final results, that the results of early stage clinical trials, such as the results from the navenibart Phase 1a clinical trial and the ALPHA-STAR trial, may not be replicated in later stage clinical trials, including the navenibart Phase 3 program; the risk that we may not be able to enroll sufficient patients in our clinical trials on a timely basis, and the risk that any of our clinical trials may not commence, continue or be completed on time, or at all; decisions made by, and feedback received from, the FDA and other regulatory authorities on our regulatory and clinical trial submissions and other feedback from potential clinical trial sites, including investigational review boards at such sites, and other review bodies with respect to navenibart, STAR-0310, and any other future development candidates, and devices for such product candidates; our ability to manufacture sufficient quantities of drug substance and drug product for navenibart, STAR-0310, and any other future product candidates, and devices for such product candidates, on a cost-effective and timely basis, and to develop dosages and formulation for navenibart, STAR-0310, and any other future product candidates that are patient-friendly and competitive; our ability to develop biomarker and other assays, along with the testing protocols therefore; our ability to obtain, maintain and enforce intellectual property rights for navenibart, STAR-0310, and any other future product candidates; our potential dependence on collaboration partners; competition with respect to navenibart, STAR-0310, or any of our other future product candidates; the risk that survey results and market research may not be accurate predictors of the commercial landscape for HAE, the ability of navenibart to compete in HAE, and the anticipated position and attributes of navenibart in HAE based on clinical data to date, its preclinical profile, pharmacokinetic modeling, market research and other data; risks with respect to the ability of STAR-0310 to compete in AD and the anticipated position and attributes of STAR-0310 in atopic dermatitis based on its preclinical profile; our ability to manage our cash usage and the possibility of unexpected cash expenditures; our ability to obtain necessary financing to conduct our planned activities and to manage unplanned cash requirements; the risks and uncertainties related to our ability to recognize the benefits of any additional acquisitions, licenses or similar transactions; and general economic and market conditions; as well as the risks and uncertainties discussed in the “Risk Factors” section of our Annual Report on Form 10-K for the period ended December 31, 2023 and in other filings that we may make with the Securities and Exchange Commission.

New risks and uncertainties may emerge from time to time, and it is not possible to predict all risks and uncertainties. Astria may not actually achieve the forecasts or expectations disclosed in our forward-looking statements, and investors and potential investors should not place undue reliance on Astria’s forward-looking statements. Neither Astria, nor its affiliates, advisors or representatives, undertake any obligation to publicly update or revise any forward-looking statement, whether as result of new information, future events or otherwise, except as required by law. These forward-looking statements should not be relied upon as representing Astria’s views as of any date subsequent to the date hereof.

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