Jasper Therapeutics Announces Positive Updated Phase 1b/2a Data for Briquilimab in CSU

Today, Jasper Therapeutics reported positive updated clinical data for briquilimab, a novel monoclonal antibody targeting KIT (CD117), from its ongoing clinical development program in chronic spontaneous urticaria (CSU).¹ The newly released results include additional data from the phase 1b/2a BEACON study as well as longer-term findings from an open-label extension study enrolling patients with CSU and chronic inducible urticaria (CIndU).² Collectively, these data demonstrate rapid onset of disease control, high rates of complete response, and a favorable safety profile, supporting advancement to a planned Phase 2b study in CSU in the second half of 2026.

BEACON Study

The BEACON study is a randomized, double-blind, placebo-controlled phase 1b/2a trial evaluating multiple ascending doses of subcutaneous briquilimab in adults with moderate to severe CSU inadequately controlled by high-dose antihistamines. The primary objectives are assessment of safety and tolerability, while the secondary endpoints include measures of clinical activity and pharmacokinetic/pharmacodynamic effects, such as changes in serum tryptase and mast cell density in skin. Clinical efficacy was primarily assessed using the Urticaria Activity Score over 7 days (UAS7).

The updated BEACON data includes 8 additional participants enrolled in the 240 mg loading dose followed by 180 mg every 8 weeks cohort; 6 received briquilimab and 2 received placebo. Among patients treated with briquilimab, the mean reduction in UAS7 from baseline was 31 points at 12 weeks, reflecting a substantial improvement in disease activity. Notably, 83% of treated participants achieved a complete response (UAS7 = 0) by week 3 following the initial dose, and 67% maintained a complete response at week 12.

Open Label Extension Study

Additional supportive evidence comes from the ongoing open-label extension study, which enrolls patients with CSU from BEACON and patients with CIndU from the SPOTLIGHT study who have completed their parent trials. In the extension, participants receive briquilimab 180 mg every 8 weeks. Jasper reported 12-week efficacy data for 36 patients with CSU and 17 patients with CIndU.

In the CSU cohort, 58% of patients achieved a complete response at 12 weeks, and 75% achieved either complete response or well-controlled disease, defined as UAS7 ≤6. In patients with CIndU, efficacy assessments were conducted every 8 weeks, and 65% achieved either a complete or partial response at 16 weeks, corresponding to 8 weeks after the second dose.

Safety Data

Briquilimab continued to demonstrate a favorable safety profile. In the BEACON study, no dose-limiting toxicities were observed, and adverse events potentially related to KIT blockade were infrequent, predominantly low grade, and generally resolved during continued treatment. Importantly, no participants discontinued treatment. Similarly, in long-term data with a median follow-up duration of 205 days across 63 participants (46 CSU and 17 CIndU), the drug remained well-tolerated. With this data, a phase 2b study in CSU is expected to commence in the second half of 2026.

“We are very pleased to present data from additional patients enrolled in the BEACON study, which reaffirms the potential of briquilimab to drive rapid and durable disease control in patients with CSU,” said Daniel Adelman, MD, Acting Chief Medical Officer of Jasper. “We are also pleased by the performance of the 180mg Q8W dose in the open-label extension study, with the strong efficacy observed in CSU and CIndU patients. Taken together with the favorable safety and tolerability profile observed in both studies, we believe these data are sufficient to support a differentiated profile for briquilimab in chronic urticaria. On behalf of the Jasper team, I’d like to thank the investigators and the patients who participated in the study, along with their families and caregivers.”¹

References

1. Jasper Therapeutics Reports Positive Updated Data from Briquilimab Studies in Chronic Spontaneous Urticaria. News Release. Globe Newswire. Published January 8, 2026. Accessed January 8, 2026. https://www.globenewswire.com/news-release/2026/01/08/3215192/0/en/Jasper-Therapeutics-Reports-Positive-Updated-Data-from-Briquilimab-Studies-in-Chronic-Spontaneous-Urticaria.html

2. Jasper Therapeutics Reports Clinical Data Update from Briquilimab Studies in Chronic Spontaneous Urticaria. News Release. Jasper Therapeutics. Published July 7, 2025. Accessed January 8, 2026. https://www.globenewswire.com/news-release/2025/07/07/3110945/0/en/Jasper-Therapeutics-Reports-Clinical-Data-Update-from-Briquilimab-Studies-in-Chronic-Spontaneous-Urticaria.html