Jasper Therapeutics (JSPR) investor relations material

Study background and objectives

• Updated data from BEACON and open-label extension studies in chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU) were presented.

• Briquilimab is a monoclonal antibody targeting the KIT receptor, aiming for rapid mast cell depletion and disease control.

• Studies evaluated efficacy, safety, and dosing regimens, informing phase 2b trial design.

• Briquilimab's differentiated mechanism and rapid clinical effect position it as a promising candidate for chronic urticaria and other mast cell-driven diseases.

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.

• Mean UAS7 scores dropped by 31 points at week 12, indicating significant disease control and rapid onset of effect.

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

• In CSU, 62% achieved complete response at week 20, with progressive UAS7 reductions over time.

• Rapid onset of effect was reported, with most patients experiencing complete or well-controlled disease by week 2.

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 observed.

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

• In the open-label extension, only 1.6% of patients discontinued due to adverse events, and no grade 3 or higher treatment-related events were reported.

• Median follow-up exceeded 200 days in the extension study, supporting long-term safety and chronic use.