In the BEACON Phase 1b/2a trial of subcutaneous briquilimab in adults with moderate to severe chronic spontaneous urticaria refractory to high‐dose antihistamines, six additional patients dosed with briquilimab (240 mg loading followed by 180 mg every eight weeks) achieved a mean UAS7 reduction of 31 points at 12 weeks. By week 3, 83% of these patients attained a complete response (UAS7=0), and at week 12, 67% maintained complete disease control. Two of the eight newly enrolled participants were randomized to placebo, underscoring the robust signal in the active arm. These results expand on prior data and reinforce briquilimab’s rapid onset of action in this patient population.

In the ongoing open-label extension study, 36 patients with chronic spontaneous urticaria treated with briquilimab 180 mg every eight weeks achieved a 75% rate of complete response or well-controlled disease (UAS7≤6) at 12 weeks, including a 58% complete response rate. Among 17 chronic inducible urticaria patients, 65% achieved complete or partial response by week 16, eight weeks after the second dose. With a median follow-up of 205 days across 63 participants, adverse events related to KIT blockade remained infrequent and predominantly low grade, with no dose-limiting toxicities, discontinuations or dose delays reported. Most events resolved on study without intervention.

Based on these efficacy and safety data, Jasper Therapeutics has selected dose regimens for a planned Phase 2b chronic spontaneous urticaria study, slated to commence in the second half of 2026. The company will host a conference call and webinar at 8:00 a.m. ET today to review data highlights, discuss dose selection rationale, and outline upcoming trial milestones. Management highlighted more than six months of median exposure in over 63 patients as sufficient to support a differentiated product profile and accelerated development timeline.