Jasper Therapeutics (JSPR) TD Cowen 46th Annual Health Care Conference summary

Key clinical updates and data

• Briquilimab, a c-Kit inhibitor, demonstrated rapid and deep disease control in phase I/II studies for chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU), with significant reductions in disease scores and serum tryptase levels within weeks of dosing.

• In the BEACON study, high-dose cohorts showed rapid improvement in UAS7 scores, with many patients achieving well-controlled or complete response status within two weeks.

• Safety profile was favorable, with most adverse events being mild and transient, including minor changes in hair color, taste, and neutrophil counts, none leading to significant discontinuations.

• The SPOTLIGHT trial in CIndU showed all patients in the highest dose cohort achieved partial or complete response by week eight.

• Proof-of-concept in allergic asthma indicated reduced eosinophil recruitment and improved lung function following allergen challenge after a single dose.

Competitive landscape and positioning

• c-Kit inhibition offers a differentiated mechanism by depleting mast cells, unlike other approved therapies (Xolair, DUPIXENT, Rhapsido) that only inhibit degranulation.

• Current CSU treatment algorithm starts with high-dose antihistamines, followed by Xolair; c-Kit inhibitors could be positioned as a next-line option, especially valuable for both CSU and CIndU indications.

• DUPIXENT and Rhapsido have limitations in efficacy or safety, and c-Kit inhibitors may offer faster onset and broader applicability.

• Having a single therapy for both spontaneous and inducible urticaria simplifies treatment for physicians and patients.

Development plans and strategy

• Phase II-B/III trial in CSU is planned for the second half of the year, testing two dosing regimens versus placebo, with dose selection informed by PK/PD modeling and observed data.

• One regimen will maintain KIT receptor saturation for maximal efficacy, while the other will allow partial recovery to optimize safety.

• Final dose and schedule decisions are pending further analysis, with a focus on balancing efficacy and minimizing KIT-related adverse events.

• Phase III studies in both CSU and CIndU are planned, aiming for simultaneous market entry in both indications.

• Asthma program may advance to phase II in 2027, contingent on resources.