Jasper Therapeutics Inc. (NASDAQ:JSPR) jumped 17.4% in premarket trading Tuesday after the company released promising initial findings from its ETESIAN Phase 1b trial evaluating briquilimab in patients with asthma.
The preliminary results indicated that a single 180 mg subcutaneous dose of briquilimab led to notable reductions in sputum eosinophils at both the six- and twelve-week marks. Patients also experienced improvements in FEV1, reflecting better lung function during both Early and Late Asthmatic Responses. In addition, the treatment produced significant declines in serum tryptase, echoing trends seen in previous briquilimab research.
Participants receiving briquilimab demonstrated a 10.4% improvement in Late Asthmatic Response at week six and an 8.7% improvement at week twelve from baseline. Jasper said the therapy was well-tolerated and maintained a favorable safety profile throughout the study.
“I am pleased to see the initial results of the ETESIAN study, the first clinical study to evaluate an agent specifically targeting mast cells in asthma patients,” said Dr. Elliot Israel, Director of Clinical Research in the Pulmonary and Critical Care Division at the Brigham and Women’s Hospital in Boston. “The initial results demonstrate the potential to reduce both airway hyperresponsiveness and the accumulation of eosinophils in the airways, both of which are key factors in managing chronic asthma and reducing exacerbations.”
The company also reported that it has wrapped up its internal review into irregular data from its BEACON trial in chronic spontaneous urticaria (CSU). Jasper concluded the unusual efficacy signals seen among U.S. patients were most likely due to patient selection inconsistencies rather than any manufacturing or product-related issues.
Jasper continues to advance briquilimab, an antibody designed to inhibit KIT (CD117), as a potential treatment for mast cell–driven disorders, including CSU and asthma.