Efficacy and Safety of LP-003 in Patients With CSU Who Remain Symptomatic Despite Antihistamine (H1) Treatment

Multi-center,Randomized,Double-blind Phase II Study to Evaluate the Efficacy and Safety of LP-003 in Patients With Chronic Spontaneous Urticaria (CSU) Who Remain Symptomatic Despite Antihistamine (H1) Treatment

The study is a Phase II, multicenter, randomized, double-blind study to evaluatethe efficacy and safety of LP-003 administered subcutaneously as an add-on therapy for the treatment of adult patients aged 18-75 who have been diagnosed with refractory CSU and who remain symptomatic despitestandard-dose H1 antihistamine treatment.

Study Overview

• Status: Completed
• Conditions: Chronic Spontaneous Urticaria
• Intervention / Treatment: Biological: Placebo; Biological: LP-003; Biological: Omalizumab

• Study Type: Interventional
• Enrollment (Actual): 202
• Phase: Phase 2

Contacts and Locations

Study Locations

• China
  • Hangzhou, China
    • The Second Affiliated Hospital Zhejiang University School of Medicine
  • Hangzhou, China
    • Hangzhou First People's Hospital
  • Wuhan, China
    • Wuhan No.1 Hospital
  • Zhenjiang, China
    • Affiliated Hospital of Jiangsu University
  • Beijing Municipality
    • Beijing, Beijing Municipality, China
      • Peking University Third Hospital
    • Beijing, Beijing Municipality, China
      • Peking Union Medical College Hospital, Chinese Academy of Medical Sciences
    • Beijing, Beijing Municipality, China
      • Beijing Friendship Hospital, Capital Medical University
    • Beijing, Beijing Municipality, China
      • The First Affiliated Hospital of China Medical University
    • Beijing, Beijing Municipality, China
      • The First Hospital of Peking University
  • Chongqing Municipality
    • Chongqing, Chongqing Municipality, China
      • The First Affiliated Hospital of PLA Army Medical University
  • Fujian
    • Fuzhou, Fujian, China
      • Fujian Medical University Union Hospital
  • Guangdong
    • Guangzhou, Guangdong, China
      • The Second Affiliated Hospital of Guangzhou Medical University
    • Guangzhou, Guangdong, China
      • Dermatology Hospital of Southern Medical University
  • Hubei
    • Wuhan, Hubei, China
      • Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology
  • Hunan
    • Changsha, Hunan, China
      • The second Xiangya hospital of central south university
  • Jiangsu
    • Nanjing, Jiangsu, China
      • Hospital of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College
  • Liaoning
    • Shenyang, Liaoning, China
      • Shengjing Hospital Of China Medical University
  • Shanghai Municipality
    • Shanghai, Shanghai Municipality, China
      • Ruijin Hospital Affiliated to Shanghai Jiaotong University School of Medicine
    • Shanghai, Shanghai Municipality, China
      • Shanghai skin disease hospital
  • Shanxi
    • Xi’an, Shanxi, China
      • The Second Affiliated Hospital of Xi'an Jiaotong University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Aged 18 to 75 years at the screening period.
2. Presence of wheals with itching for ≥ 6 weeks prior to randomization. At the screening visit, subjects had taken double or more than the approved dose, or a combination of two or more H1 antihistamines for the treatment of chronic spontaneous urticaria for at least 2 weeks. Within the 7 days preceding randomization, the Urticaria Activity Score 7 (UAS7) was ≥16 (range 0-42), Itch Severity Score 7 (ISS7) was ≥8 (range 0-21), at least one UAS (range 0-6) was ≥4 on any screening visit day, and there must be a current record of medication use.
3. Subjects must not miss more than one diary record (morning or night) within 7 days prior to randomization (day 1), and are willing and able to complete daily symptom electronic diary records during the study period;
4. Male participants and their partners or female participants must agree to take one or more non pharmacological contraceptive measures (such as complete abstinence, contraceptive ring, partner ligation, etc.) during the trial period and within 6 months after the end of the trial and have no plans for sperm or egg donation.
5. Agree to participate in this clinical trial and voluntarily sign an informed consent form.

Exclusion Criteria:

1. The subject has a primary or sole trigger for chronic urticaria (chronic Induced urticaria), including artificial urticaria (symptomatic skin scratch disease), cold, heat, sun, pressure, delayed pressure, water, cholinergic, or contact urticaria;
2. Other medical conditions accompanied by symptoms of urticaria or angioedema including, but not limited to, urticarial vasculitis, pigmented urticaria, erythema multiforme, mastocytosis, hereditary urticaria, or drug-induced urticaria;
3. Any other dermatologic condition with chronic itching, such as atopic dermatitis, herpetic pemphigoid, herpetic dermatitis, senile itching, or psoriasis, which in the judgment of the Investigator may affect the evaluation of the study and the results of the study;
4. Subjects with clinically significant conditions such as (but not limited to) unstable ischemic heart disease, NYHA Class III/IV left ventricular failure, cardiac arrhythmias, uncontrolled hypertension, cerebrovascular disease, neurodegenerative, or other neurological disorders, uncontrolled hypothyroidism and hyperthyroidism and other autoimmune disorders, hypokalemia, hyper adrenergic state; past diagnosis of malignancy (other than basal cell carcinoma or squamous cell skin cancer); history of myocardial infarction within 12 months prior to screening;
5. Acute active infections requiring treatment at screening, including but not limited to, pulmonary infections, tuberculosis;
6. Positive hepatitis B surface antigen or hepatitis B core antibody (except for HBV-DNA testing below the lower limit of the research center's test) at screening; positive hepatitis C virus antibody, human immunodeficiency virus (HIV) antibody, and anti-syphilis helical antibody (TP-Ab) (except for those who are negative for RPR or TRUST);
7. Clinically significant cardiovascular, neurological, psychiatric, metabolic, hepatic, or other abnormalities identified during the Screening Period that may affect the interpretation of the study results and/or the safety of the subject;
8. Comorbid neurological or psychiatric disorders that prevent or prevent cooperation; patients with disabilities as defined by law (blindness, deafness, mute, mental retardation, psychiatric disorders, etc.);
9. Major surgery within 8 weeks prior to screening or surgery planned during the study period;
10. Evidence of historical or ongoing alcohol or substance abuse in the 6 months prior to screening;
11. Poor compliance, such as low medication adherence, inability to accurately complete a diary card, or use of prohibited medications;
12. Pregnant women, nursing mothers, or those with recent birth plans;
13. Patients who have participated in clinical trials of other drugs within the last 3 months;
14. Those who are considered by the investigator to be unfit to participate in the clinical trial.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

5

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: LP-003 group 1; Participants received LP-003 subcutaneously during the 24-week treatment period	Biological: LP-003; Liquid in vial
Experimental: LP-003 group 2; Participants received LP-003 subcutaneously during the 24-week treatment period	Biological: LP-003; Liquid in vial
Experimental: LP-003 group 3; Participants received LP-003 subcutaneously during the 24-week treatment period	Biological: LP-003; Liquid in vial
Active Comparator: Omalizumab; Participants received omalizumab 300 mg subcutaneously every 4 weeks during the 24-week treatment period	Biological: Omalizumab; Liquid in vial
Placebo Comparator: Placebo; Participants received placebo subcutaneously every 4 weeks during the 24-week treatment period	Biological: Placebo; Liquid in vial

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
The proportion of participants achieving complete absence of wheals and itching (UAS7 = 0) at week 12	Week 12

Secondary Outcome Measures

Outcome Measure	Time Frame
The incidence of adverse events during the study	40 weeks
The proportion of participants with no hives (HSS7 = 0) at week 4, 8, 12, 16, 20, 24, 32, and 40	Week 4, 8, 12, 16, 20, 24, 32, and 40
The proportion of participants achieving complete absence of wheals and itching (UAS7 = 0) at week 4, 8, 16, 20, 24, 32, and 40	Week 4, 8, 16, 20, 24, 32, and 40
The proportion of participants achieving complete absence of angioedema (AAS7 = 0) at week 4, 8, 12, 16, 20, 24, 32, and 40	Week 4, 8, 12, 16, 20, 24, 32, and 40
The proportion of participants with controlled disease activity (UAS7 ≤ 6) at week 4, 8, 12, 16, 20, 24, 32, and 40	Week 4, 8, 12, 16, 20, 24, 32, and 40
Change From Baseline in UAS7, HSS7, ISS7, AAS7 at week 4, 8, 12, 16, 20, 24, 32, and 40	Baseline and week 4, 8, 12, 16, 20, 24, 32, and 40
Change From Baseline in Chronic Urticaria Quality of Life Questionnaire (CU-Q2oL) at week 4, 8, 12, 16, 20, 24, 32, and 40	Baseline and week 4, 8, 12, 16, 20, 24, 32, and 40
Blood concentrations of LP-003, free IgE, total IgE, anti-drug antibodies (ADA), and neutralizing antibodies (Nab) during the study	40 weeks

Collaborators and Investigators

• Sponsor: Longbio Pharma

Study record dates

Study Major Dates

• Study Start (Actual): January 26, 2024
• Primary Completion (Actual): April 17, 2025
• Study Completion (Actual): November 14, 2025

Study Registration Dates

• First Submitted: January 18, 2024
• First Submitted That Met QC Criteria: January 18, 2024
• First Posted (Actual): January 29, 2024

Study Record Updates

• Last Update Posted (Actual): December 12, 2025
• Last Update Submitted That Met QC Criteria: December 5, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Chronic Disease; Disease Attributes; Immune System Diseases; Hypersensitivity, Immediate; Hypersensitivity; Skin Diseases; Urticaria; Skin Diseases, Vascular; Pathological Conditions, Signs and Symptoms; Skin and Connective Tissue Diseases; Chronic Urticaria; Amino Acids, Peptides, and Proteins; Proteins; Antibodies, Monoclonal, Humanized; Antibodies, Monoclonal; Antibodies; Immunoglobulins; Immunoproteins; Blood Proteins; Serum Globulins; Globulins; Antibodies, Anti-Idiotypic; Omalizumab
• Other Study ID Numbers: P10-LP003-03

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No