BOSTON — Astria Therapeutics, Inc. (NASDAQ: ATXS), a biopharmaceutical company developing therapies for allergic and immunologic diseases, announced final results from the full enrollment of 29 patients in the ALPHA-STAR Phase 1b/2 trial of navenibart (STAR-0215), a monoclonal antibody inhibitor of plasma kallikrein for the prevention of hereditary angioedema (HAE) attacks. The results remained consistent with earlier findings from the initial target enrollment group of 16 patients, showing strong efficacy, a favorable safety profile, and the potential for infrequent dosing.
The company also noted continued progress of the Phase 3 ALPHA-ORBIT trial, with topline results expected in early 2027, and confirmed that the first patient has been enrolled in the ORBIT-EXPANSE long-term extension study.
“The updated results from the full 29 patients in the ALPHA-STAR Phase 1b/2 trial are highly encouraging and reinforce our confidence in navenibart’s profile as a potentially life-changing preventative treatment for HAE,” said Christopher Morabito, M.D., Chief Medical Officer at Astria Therapeutics. “With nearly double the target enrollment, the data are highly consistent with previously reported results and demonstrate rapid onset, robust and durable efficacy, and a favorable safety and tolerability profile. Importantly, we also observed sustained, clinically meaningful improvements in patient-reported quality of life. The results strongly support both every three-month and every six-month dosing regimens, and we look forward to navenibart’s progress in the ALPHA-ORBIT Phase 3 trial, which is enrolling globally.”
ALPHA-STAR was a dose-ranging proof-of-concept trial evaluating safety, tolerability, efficacy, pharmacokinetics, pharmacodynamics, and patient-reported quality of life in adults with HAE Type 1 or 2. Patients received single or multiple subcutaneous doses of navenibart across three dosing cohorts following an eight-week baseline run-in period. Due to rapid enrollment and patient interest, the study expanded from its original target of 16 participants to a total of 29, increasing the size of the clinical safety database for future regulatory submissions.
Key findings from the ALPHA-STAR trial showed mean/median reductions in attack rates over six months as follows:
Cohort 1 (n=4), single 450 mg dose: 84% / 93%
Cohort 2 (n=13), 600 mg dose followed by 300 mg at three months: 90% / 100%
Cohort 3 (n=12), 600 mg dose followed by 600 mg at one month: 92% / 100%
Expanded Cohorts 2 and 3 demonstrated attack-free rates of 62% and 67%, respectively, consistent with prior results. Patients also reported meaningful improvements in quality of life at six months across all cohorts.
Navenibart was generally well-tolerated, with no serious treatment-emergent adverse events, no discontinuations, and no cases of injection site pain. Four non-severe and quickly resolved treatment-related events were observed.
All 29 patients elected to continue treatment in the ALPHA-SOLAR long-term open-label extension trial.
