Jasper Therapeutics Announces Positive SPOTLIGHT Study Results for Briquilimab in Chronic Inducible Urticaria

Jasper Therapeutics, Inc., a clinical-stage biotechnology firm listed on Nasdaq under the ticker JSPR, focuses on developing briquilimab, an innovative antibody therapy targeting c-Kit (CD117). This therapy aims to tackle mast cell-driven diseases such as chronic spontaneous urticaria (CSU), chronic inducible urticaria (CIndU), and asthma. Recently, Jasper shared preliminary data from its ongoing SPOTLIGHT Phase 1b/2a study examining subcutaneous briquilimab in adult patients with cold urticaria (ColdU) or symptomatic dermographism (SD), which are the most common subtypes of CIndU.

The study involved 15 participants, and within six weeks of treatment, 93% (14 out of 15) showed a clinical response. Specifically, in the 120mg dose cohort, 83% (10 out of 12) achieved a complete response (CR), with one participant showing a partial response (PR). The treatment was well tolerated with no serious adverse events (SAEs) or grade 3 or higher adverse events (AEs) reported. Jasper also received regulatory approval to enroll a 180mg dose cohort in the SPOTLIGHT study and expects to present full data from this study in the first half of 2025.

Jasper anticipates reporting initial data from all cohorts of the BEACON study in CSU, including the newly added 180mg Q8W dose cohort, in early January 2025. Ronald Martell, President and CEO of Jasper, expressed enthusiasm over the positive data from the SPOTLIGHT study, highlighting an over 80% complete response rate in the 120mg cohort and the treatment’s favorable tolerability. Martell emphasized briquilimab's potential to offer robust and durable clinical benefits along with a promising safety profile.

The SPOTLIGHT study is an open-label clinical trial evaluating a single dose of subcutaneous briquilimab in adult patients with ColdU or SD who do not respond to antihistamines. The study plans to enroll 27 patients across three dose cohorts: 40mg, 120mg, and 180mg. Primary endpoints include safety and tolerability, while secondary endpoints focus on clinical activity and pharmacokinetics/pharmacodynamics (PK/PD). Participants’ symptoms are induced via provocation testing before dosing and at various time points up to 12 weeks post-dosing.

As of October 10, 2024, 15 participants had been enrolled and received a single dose of briquilimab, with all having at least six weeks of follow-up. In the 120mg cohort, significant improvements were noted, with mean baseline TempTest® threshold and FricTest® scores showing marked reductions. The 93% clinical response rate included 83% achieving a complete response. Temperature and friction test scores improved significantly within one week of dosing.

Additionally, mean baseline serum tryptase levels, a marker for mast cell activity, were reduced by up to 66% in the 120mg cohort two weeks after treatment. At the six-week assessment, a 31% reduction in mean tryptase levels was observed, with 58% of participants maintaining a clinical response.

The study demonstrated that briquilimab was well tolerated, with no SAEs or grade 3 AEs reported. No adverse events related to hair or skin color changes, hypersensitivity, or anemia were noted, and only mild decreases in neutrophil counts were observed.

Dr. Martin Metz, Professor of Dermatology and Allergy at Charité – Universitätsmedizin Berlin, praised the initial clinical data, noting briquilimab’s potential for significant clinical benefits in difficult-to-treat CIndU patients. He was also encouraged by the safety and tolerability profile, especially the absence of hypopigmentation or hair color changes.

Briquilimab is a targeted aglycosylated monoclonal antibody that prevents stem cell factor from binding to the c-Kit receptor, leading to the depletion of mast cells and addressing the source of inflammation in mast cell-driven diseases. Jasper is conducting clinical studies of briquilimab in patients with CSU or CIndU and is initiating trials in asthma patients. Additionally, briquilimab is being studied as a treatment for lower-risk myelodysplastic syndromes (LR-MDS) and as a conditioning agent for cell therapies in rare diseases. To date, briquilimab has shown a favorable efficacy and safety profile in over 160 dosed participants across various studies, including those for SCID, AML, MDS, Fanconi anemia, and sickle cell disease.

Jasper Therapeutics continues to advance the clinical development of briquilimab, striving to provide new treatment options for patients with chronic urticaria, asthma, and other related conditions.