RAPT Therapeutics(US:RAPT) Globenewswireยท2025-10-20 12:00Core Insights - RAPT Therapeutics and Shanghai Jeyou Pharmaceutical announced positive topline data from a Phase 2 trial of RPT904 for chronic spontaneous urticaria, showing comparable efficacy and safety to omalizumab [1][4][5] Study Design and Results - The Phase 2 study enrolled 137 adult patients with chronic spontaneous urticaria inadequately controlled by H1 antihistamines, randomized into three arms: RPT904 Q8W, RPT904 Q12W, and omalizumab Q4W [2] - The primary endpoint was the change in the seven-day urticaria activity score (UAS7) at Weeks 8, 12, and 16, with key secondary endpoints including the proportion of patients achieving UAS7=0 [2] - RPT904 demonstrated numerically greater improvements in UAS7 scores and a higher proportion of patients achieving UAS7=0 compared to omalizumab at all time points [3] Efficacy Data - Mean baseline UAS7 scores were similar across treatment arms, with RPT904 Q8W showing a least squares mean change from baseline of -20.51 at Week 8, -22.14 at Week 12, and -23.20 at Week 16 [3] - The proportion of patients with UAS7=0 at Week 16 was 45.65% for RPT904 Q8W and 43.48% for Q12W, compared to 33.33% for omalizumab [3] Safety Profile - RPT904 was well tolerated, with no serious adverse events related to the study drug and no treatment-related discontinuations [3][4] Future Development Plans - Jeyou plans to advance RPT904 to Phase 3 development in China, while RAPT will discuss the Phase 3 development path with the FDA [4][5] - RAPT also aims to initiate a Phase 2b trial in food allergies by the end of the year [5] Background Information - Chronic spontaneous urticaria is characterized by sudden onset hives and intense itch, with a need for therapies targeting the underlying IgE-autoantibody pathology [7] - RPT904 is a novel anti-IgE monoclonal antibody designed to provide extended pharmacokinetics compared to omalizumab, targeting the same epitope [8]