BOSTON, Mass. — Astria Therapeutics, Inc. (NASDAQ:ATXS), a biopharmaceutical company focused on developing life-changing therapies for allergic and immunological diseases, today announced positive initial proof-of-concept results from the ALPHA-STAR Phase 1b/2 clinical trial evaluating STAR-0215, a monoclonal antibody inhibitor of plasma kallikrein, in hereditary angioedema (HAE) patients. Initial results demonstrate a favorable safety and tolerability profile, mean monthly attack rate reduction of 90-96% for up to 6 months of follow up, and support both three- (Q3M) and six-month (Q6M) dosing regimens. Based on the positive results, Astria plans to advance STAR-0215 to Phase 3 development with trial initiation expected in Q1 2025 and top-line results expected by year-end 2026.
We are thrilled with these initial results from ALPHA-STAR and believe that STAR-0215 can be a transformative therapy for patients that greatly reduces their disease and treatment burdens,” said Christopher Morabito, M.D., Chief Medical Officer at Astria Therapeutics. “These results give us conviction that we will be able to deliver STAR-0215 once every three and six months, and we look forward to progressing this program into Phase 3 as quickly as possible.”
“The initial results of the ALPHA-STAR trial represent a very exciting step forward in the HAE treatment landscape,” said Marcus Maurer, M.D., Executive Director of the Institute of Allergology at Charite – Universitatsmedizin Berlin. “STAR-0215 has the potential to help patients manage their disease with a mechanism and modality that they trust, but with a substantially improved dosing regimen and the ability to administer without pain. Based on this profile, STAR-0215 has the potential to normalize the lives of people living with HAE.”
“Thanks to the enthusiasm for STAR-0215, the ALPHA-STAR trial enrolled ahead of schedule, enabling us to report these data earlier than originally scheduled,” said Jill C. Milne, Ph.D., Chief Executive Officer. “We believe STAR-0215 has the potential to be the first-choice HAE treatment and I am thankful for the HAE community and the Astria team for helping us to achieve today’s important milestone.”
ALPHA-STAR is a dose-ranging proof-of-concept trial in adults with HAE Type 1 or 2 designed to assess safety, tolerability, efficacy, pharmacokinetics (PK), pharmacodynamics (PD), and quality of life in patients receiving single and multiple doses of STAR-0215 delivered subcutaneously to prevent attacks in HAE. Target enrollment of 16 patients has been achieved and all doses have been administered. All cohorts began with an eight-week run-in period to measure baseline HAE attacks and safety, efficacy, PK, and PD are assessed through 6-months (Day 168) after the last dose received. The initial efficacy and safety data-cut was as of March 13, 2024.
Cohort 1 evaluated a 450 mg dose and all four patients have completed 6 months of follow-up. Efficacy observations compared to baseline through 6 months of follow-up were as follows:
- 92% reduction in monthly attack rate
- 96% reduction in moderate and severe attacks
- 91% reduction in acute rescue medication use
- 50% of patients were attack-free through 3 months of follow-up
Cohort 2 evaluated a 600 mg dose followed by a 300 mg dose three months later, on Day 84. The Company plans to evaluate this dosing regimen in Phase 3. All six patients have completed 3 months of follow up and three patients have completed 6 months of follow-up. Efficacy observations compared to baseline through 6 months of follow-up were as follows:
- 96% reduction in monthly attack rate
- 98% reduction in moderate and severe attacks
- 94% reduction in acute rescue medication use
- 67% of patients were attack-free
- 100% of patients were attack-free in the first month after dosing, demonstrating rapid onset of action
Cohort 3 received a 600 mg dose followed by a 600 mg dose one month later, on Day 28. Four of six patients have completed 3 months of follow-up. Efficacy observations compared to baseline through 3 months of follow-up were as follows:
- 90% reduction in monthly attack rate
- 100% reduction in moderate and severe attacks
- 95% reduction in acute rescue medication use
- 50% of patients were attack-free
Preliminary PK and PD data are consistent with Phase 1a data in healthy subjects and consistent with observed efficacy.
STAR-0215 was generally well-tolerated with no serious treatment-emergent adverse events (TEAEs) and no discontinuations. There were two treatment-related TEAEs (both mild), one of which was a case of dizziness and the other a transient injection site reaction (rash). There were no injection site reactions of pain.
After completion of the ALPHA-STAR trial, patients have the opportunity to continue to receive STAR-0215 every three or six months in the long-term open label ALPHA-SOLAR trial. Initial safety and efficacy data from Q3M and Q6M dosing in the ALPHA-SOLAR trial are expected mid-2025.
The observed efficacy, PK, PD, and safety and tolerability profile of STAR-0215 support advancement of STAR-0215 into Phase 3 development. To progress STAR-0215 to market as quickly as possible, the Company plans to focus the Phase 3 program on Q3M dosing initially, immediately followed by a second trial to support label expansion to Q6M. Pending regulatory feedback, the Company expects to start a pivotal Q3M Phase 3 trial in Q1 2025, with top-line results expected by year-end 2026.
The Company expects that its current cash, cash equivalents, and short-term investments of $246.5 million as of December 31, 2023, plus $137.1 million from financing activity in the first quarter of 2024, will be sufficient to fund the Company into mid-2027 including all STAR-0215 program activities through the completion of a planned Q3M Phase 3 pivotal trial as well as advancing the Company’s STAR-0310 OX40 program through IND submission and early proof-of-concept results from a Phase 1a trial.
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 immunological diseases. Our lead program, 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 preclinical development for the treatment of atopic dermatitis.
About STAR-0215
STAR-0215 is a monoclonal antibody inhibitor of plasma kallikrein in development for the treatment of HAE. Our goal with STAR-0215 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 living with HAE to live life without limitations from their disease. Pending regulatory feedback, we expect to initiate a pivotal Q3M Phase 3 trial in Q1 of 2025 with top-line results expected by year-end 2026.