BOSTON– Astria Therapeutics, Inc. (NASDAQ: ATXS), a biopharmaceutical company focused on developing therapies for allergic and immunologic diseases, announced positive initial results from its Phase 1a trial of STAR-0310, a half-life extended monoclonal antibody antagonist of OX40, in healthy participants. The findings will be presented by Dr. Stephan Weidinger, M.D., Ph.D., at the European Academy of Dermatology and Venereology Congress on September 18.
STAR-0310 demonstrated a half-life of up to 68 days, the longest reported among investigational OX40/OX40L antibodies, supporting the potential for dosing every six months. The treatment showed rapid and sustained target engagement, durable cytokine suppression lasting at least 20 weeks after a single 300 mg subcutaneous injection, and was well-tolerated without antibody-dependent cellular cytotoxicity (ADCC)-related adverse events. These results suggest a wider therapeutic window than first-generation OX40 therapies, which have been limited by safety concerns.
“The Phase 1a results of STAR-0310 show compelling early differentiation,” said Christopher Morabito, M.D., Chief Medical Officer at Astria Therapeutics. “We saw rapid and durable pharmacodynamic effects without fever, chills, or dose-limiting side effects seen in earlier OX40 therapies. The data support STAR-0310 as a candidate for infrequent, every-six-month administration with the potential to provide differentiated, long-lasting efficacy for people with atopic dermatitis, particularly those who do not respond to existing biologics such as Dupixent.”
STAR-0310 was observed to be well-tolerated at all dose levels, with no serious treatment-emergent adverse events or discontinuations. Mild treatment-related effects were seen in some participants but resolved without intervention. Biomarker analysis confirmed durable ex vivo cytokine inhibition, including IL-2, IL-22, IL-31, and IL-4, for up to 20 weeks, suggesting that STAR-0310 modulates a broad spectrum of immune pathways beyond Th-2.
The Phase 1a study is a randomized, double-blind, placebo-controlled single ascending dose trial evaluating safety, tolerability, pharmacokinetics, and immunogenicity in 32 adults across four dose cohorts ranging from 150 mg to 1200 mg. This interim analysis included data from all cohorts through follow-up windows ranging from 84 to 168 days. Astria said it expects to provide an update on development plans for STAR-0310 in the coming months.
