Longbio Pharma announced breakthrough interim results from its Phase II clinical trial of LP-003, a novel long-acting anti-IgE antibody, for the treatment of Chronic Spontaneous Urticaria (CSU) at the 2025 American Academy of Allergy, Asthma & Immunology annual meeting (AAAAI 2025) in San Diego.
Superior Efficacy and Extended Dosing Benefits
The multi-center, double-blind, placebo-controlled study evaluated multiple dosing regimens of LP-003 against Omalizumab and placebo, with 40 patients per group. LP-003 demonstrated superior improvement in mean change of UAS7 (urticaria activity score 7) from baseline at week 12, alongside higher percentages of patients achieving complete symptom resolution (UAS7=0) at both week 4 and week 12.
Patients received LP-003 at doses of 100mg or 200mg every 8 weeks (Q8W), or 200mg every 4 weeks (Q4W), compared to standard 300mg Omalizumab treatment. The drug showed dose-dependent rapid and sustained relief of CSU symptoms while maintaining a favorable safety profile comparable to placebo.
Market Positioning and Clinical Impact
CSU affects approximately 1-2% of the global population, with about 35% of patients showing inadequate response to first-line antihistamine treatments. The U.S. market for CSU treatments is projected to reach $2 billion by 2026, with an expected 8-10% CAGR over the following five years.
LP-003's efficacy results proved comparable to barzolvolimab, an anti-C-KIT mAb developed by Celldex, without raising additional safety concerns. Market research from RAPT indicates that healthcare providers prefer less frequent dosing schedules, even with marginally lower efficacy, making LP-003's extended dosing interval particularly attractive.
Expanding Therapeutic Applications
Following its success in allergic rhinitis, Longbio is advancing LP-003's development program across multiple allergic conditions. The company has initiated a Phase II trial in asthma, with China's NMPA approving a quarterly dosing schedule. Additionally, LP-003 received IND approval for food allergy studies, targeting a market estimated to exceed $10 billion USD.
Clinical Trial Details
The Phase II trial (NCT06228560) focuses on evaluating LP-003's efficacy and safety in CSU patients. Key endpoints include:
- Primary: Proportion of participants achieving complete symptom resolution (UAS7 = 0) at week 12
- Secondary: Mean UAS7 change from baseline at weeks 4 and 12
- Safety and additional efficacy measures
Dr. James Chen, Principal Investigator at the San Diego Research Center, noted, "The interim results suggest LP-003 could represent a significant advancement in CSU treatment, offering patients both improved efficacy and a more convenient dosing schedule."
