Jasper Therapeutics (JSPR) Study Result summary

Study Overview and Objectives

• Presented updated data from BEACON and open-label extension studies in chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU), focusing on briquilimab, an anti-KIT antibody, for rapid and durable disease control.

• Data update included new patients and longer-term follow-up for efficacy and safety.

• Results support advancing to a phase 2b study in CSU, planned for the second half of 2026, with dose selection enabled by accumulated data.

Efficacy and Clinical Response

• In BEACON, 83% of patients in the 240mg/180mg Q8W cohort achieved complete response by week 3, and 67% maintained complete response at week 12, with a mean UAS7 reduction of 31 points.

• In the open-label extension, 75% of CSU patients achieved complete or well-controlled disease at 12 weeks, and 65% of CIndU patients maintained clinical response at week 16.

• CSU patients in the extension showed progressive UAS7 reductions, with up to 62% achieving complete response at week 20.

• Rapid onset of effect observed, with most patients experiencing response as early as week one or two.

Safety and Tolerability

• Briquilimab demonstrated a favorable safety profile, with most adverse events being low-grade, transient, and resolving during treatment.

• No dose-limiting toxicities or discontinuations due to treatment-related adverse events were reported.

• KIT-related adverse events, such as taste changes and neutrophil count decreases, were infrequent and typically resolved without discontinuation.

• Median exposure in the open-label extension exceeded 200 days, supporting long-term tolerability.

• Serious adverse events were rare, and no treatment-related deaths or grade 3 or higher events occurred.