Summary of Jasper Therapeutics Data Update Webinar Company Overview - **Company**: Jasper Therapeutics (NasdaqCM:JSPR) - **Date of Call**: December 2, 2025 Key Points Industry and Company Focus - **Industry**: Biotechnology, specifically focusing on treatments for chronic spontaneous urticaria (CSU) and allergic asthma - **Core Product**: Briquilimab, a drug targeting mast cells BEACON Trial Findings - **Unexpected Results**: In the BEACON trial for CSU, none of the 10 U.S. patients in Cohort 8 achieved complete response by week 12, contrasting with two out of three patients in EU sites who did respond, indicating potential issues with drug lot A34954 used in the U.S. [4][5] - **Investigation**: An internal investigation was launched, reviewing manufacturing records, drug handling, and patient data. No significant deviations were found in drug production or handling [5][10][11]. - **Patient-Specific Factors**: The investigation concluded that patient-specific factors likely caused the unexpected results, with many patients possibly not having CSU [11][17]. Redosing Data from BEACON - **Cohorts 8 and 9**: Patients were switched to a new drug lot (34955) during the trial, showing no changes in pharmacokinetics (PK) or pharmacodynamics (PD) measures after redosing [12][15]. - **Clinical Outcomes**: The drug effectively depleted mast cells, as indicated by reduced tryptase levels, but clinical responses were not observed in many patients, suggesting misdiagnosis [15][17]. ATESIAN Study Results - **Study Design**: The ATESIAN trial assessed briquilimab's safety and efficacy in patients with mild allergic asthma, focusing on allergen challenges [20][21]. - **Efficacy Observations**: A single 180 mg dose resulted in significant reductions in serum tryptase levels and improved FEV1 responses, indicating a sustained effect on both early and late asthmatic responses [22][24]. - **Safety Profile**: Briquilimab was well tolerated with no serious treatment-related adverse events reported, reinforcing its safety in asthmatic populations [24][26]. Future Directions - **Next Steps**: Jasper plans to report additional BEACON data and open-label extension data in Q1 2026, including efficacy and safety data from new patients [26][27]. - **Broader Asthma Studies**: The company is evaluating further studies to explore briquilimab's effects across different asthma endotypes, including T2 high and T2 low diseases [25][27]. Recommendations for Future Trials - **Patient Selection**: Emphasis on quality patient selection is crucial, with recommendations to involve certified specialists in diagnosing CSU to avoid misdiagnosis [18][49]. - **Larger Sample Sizes**: Increasing sample sizes in trials may help mitigate the impact of non-mast cell-driven patients [18][67]. Conclusion - **Overall Outlook**: Jasper Therapeutics is optimistic about briquilimab's potential in treating both CSU and asthma, with ongoing investigations and upcoming data expected to support its clinical efficacy and safety [72].