A Clinical Study on the Efficacy and Safety of HBM9161 in Patients With ITP

A Randomized, Double-blind, Placebo-controlled, Phase 2/3 Operational Seamless Designed Clinical Study to Evaluate the Efficacy and Safety of HBM9161 Weekly Subcutaneous Injection in Patients With Primary Immune Thrombocytopenia

To select a dose and to make a decision for Phase 3 study

Study Overview

• Status: Completed
• Conditions: Primary Immune Thrombocytopenic Purpura
• Intervention / Treatment: Drug: HBM9161 Dose A; Drug: HBM9161 Dose B; Drug: Placebo

Detailed Description

The onset of primary immune thrombocytopenia is thought to be increased platelet destruction and decreased platelet production due to anti-platelet antibodies. HBM9161 is a fully human anti-FcRn monoclonal antibody that can effectively remove pathogenic IgG, thereby relieving platelet destruction and rapidly increasing platelet counts in patients. The study will be conducted in a Phase 2/3 operational seamless design, with group Dose A and Dose B of HBM9161 and a placebo group in Phase 2.

• Study Type: Interventional
• Enrollment (Actual): 36
• Phase: Phase 2; Phase 3

Contacts and Locations

Study Locations

• China
  • Tianjin Municipality
    • Tianjin, Tianjin Municipality, China, 300020
      • Hematology hospital, Chinese academy of medical sciences

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. ≥ 18 years of age at the screening visit, male or female.
2. Persistent or chronic ITP whose average number of platelet at the screening visit and pre-dose (at least 1 day apart) is < 30 × 10^9/L, and not > 35 × 10^9/L for any of two tests. No severe bleeding within 4 weeks prior to the screening visit.
3. Patients who have received and failed at least 1 first line of ITP therapy (glucocorticoids and/or intravenous gamma globulin), or who are contraindicated, intolerable, or refuse standard therapy.
4. Patients will be allowed to use a stable dose of concomitant drugs for the treatment of ITP. e.g., glucocorticoid, danazol, immunosuppressant (azathioprine, cyclosporine A, mycophenolate mofetil) and eltrombopag.

Exclusion Criteria:

1. Other autoimmune systemic diseases other than ITP.
2. Multi-lineage immune cytopenias, such as Evan's syndrome, autoimmune pancytopenia.
3. Secondary ITP.
4. Received a vaccine within 4 weeks prior to the first dose of the study drug or planned during the study.
5. Use of anticoagulants or any agents that have antiplatelet effect or can affect thrombopoiesis within 3 weeks prior to the first dose of the study drug.
6. Received blood transfusion within 1 week prior to the first dose of the study drug.
7. Received the intravenous gamma globulin, anti-D immunoglobulin, or plasmapheresis within 2 weeks prior to the first dose of the study drug.
8. Received high-dose dexamethasone or high-dose methylprednisolone within 2 weeks prior to the first dose of the study drug.
9. Received recombinant human thrombopoietin (rhTPO) within 4 weeks prior to the first does of the study drug.
10. Received rituximab or other non-rituximab anti-CD20 drugs within 6 months prior to the first does of the study drug.
11. Treated with splenectomy within 4 weeks prior to first dose of the study drug.
12. Any thromboembolic or embolic events within 12 months prior to the first does of the study drug.
13. Serum total IgG < 700 mg/dL at the screening visit.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: HBM9161 Dose A; Patients will be randomized in a 1:1:1 ratio to HBM9161 (Dose A or Dose B) or placebo	Drug: HBM9161 Dose A; HBM9161 (Dose A or Dose B) or matching placebo will be administered IV weekly
Experimental: HBM9161 Dose B; Patients will be randomized in a 1:1:1 ratio to HBM9161 (Dose A or Dose B) or placebo	Drug: HBM9161 Dose B; HBM9161 (Dose A or Dose B) or matching placebo will be administered IV weekly
Placebo Comparator: Placebo; Patients will be randomized in a 1:1:1 ratio to HBM9161 (Dose A or Dose B) or placebo	Drug: Placebo; HBM9161 (Dose A or Dose B) or matching placebo will be administered IV weekly

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of patients who achieve the early response.	The primary endpoint of phase 2	7 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
Proportion of patients who achieve platelet count ≥ 50 × 10^9/L at least 2 times within 7 weeks.	7 weeks

Collaborators and Investigators

• Sponsor: Harbour BioMed (Guangzhou) Co. Ltd.
• Investigators: Principal Investigator: Renchi Yang, Hematology hospital, Chinese academy of medical sciences

Study record dates

Study Major Dates

• Study Start (Actual): July 24, 2020
• Primary Completion (Actual): August 10, 2021
• Study Completion (Actual): August 11, 2021

Study Registration Dates

• First Submitted: June 9, 2020
• First Submitted That Met QC Criteria: June 9, 2020
• First Posted (Actual): June 11, 2020

Study Record Updates

• Last Update Posted (Actual): April 28, 2026
• Last Update Submitted That Met QC Criteria: April 27, 2026
• Last Verified: August 1, 2021

More Information

Terms related to this study

• Keywords: ITP
• Additional Relevant MeSH Terms: Pathologic Processes; Immune System Diseases; Autoimmune Diseases; Hematologic Diseases; Hemorrhage; Hemorrhagic Disorders; Blood Coagulation Disorders; Skin Manifestations; Thrombocytopenia; Blood Platelet Disorders; Thrombotic Microangiopathies; Purpura; Purpura, Thrombocytopenic; Purpura, Thrombocytopenic, Idiopathic
• Other Study ID Numbers: 9161.4

Drug and device information, study documents

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