SG301-SC Injection Safety Study in Subjects With Primary ITP Patients

July 13, 2026 updated by: Hangzhou Sumgen Biotech Co., Ltd.

A Randomized, Double-Blind, Placebo-Controlled Phase 2 Clinical Study to Evaluate the Safety and Efficacy of SG301 SC Injection in Patients With Primary Immune Thrombocytopenia

This is a multicenter, randomized, double-blind, placebo-controlled Phase II clinical study. The primary objective is to evaluate the safety and efficacy of SG301 SC Injection in participants with ITP, while the secondary objectives are to assess the pharmacokinetic, pharmacodynamic and immunogenicity profiles of SG301 SC Injection in ITP participants.

A total of 60 ITP participants are planned to be enrolled in this study and randomly assigned at a 1:1:1 ratio to the low dose group, high dose group and placebo group, with approximately 20 participants per group. All participants enrolled in this study may receive concomitant background therapies at stable doses for at least 4 weeks prior to the first study drug administration, and is expected to be maintained throughout the study period.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

60

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • China
    • Fujian
      • Fuzhou, Fujian, China, 350001
        • Recruiting
        • Fujian Medical University Union Hospital
        • Contact:
    • Henan
      • Pingdingshan, Henan, China, 467000
        • Recruiting
        • Pingdingshan First People's Hospital
        • Contact:
    • Shandong
      • Jining, Shandong, China, 272011
        • Recruiting
        • Jining No.1 People's Hospital
        • Contact:
    • Tianjin Municipality
      • Tianjin, Tianjin Municipality, China, 300020
        • Recruiting
        • Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences
        • Contact:
        • Contact:
    • Zhejiang
      • Wenzhou, Zhejiang, China, 325000
        • Recruiting
        • The First Affiliated Hospital of Wenzhou Medical University
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Aged 18-75 years, any gender.
  2. Voluntarily signed informed consent and able to comply with study procedures.
  3. Clinically diagnosed with primary immune thrombocytopenia (ITP) per 2019 ASH Guidelines, international consensus statements, or 2025 Chinese Guidelines for Adult ITP Diagnosis and Treatment; disease duration ≥ 3 months.
  4. Experienced treatment failure or relapse after prior first-line therapy (glucocorticoids and/or IVIG).
  5. ≥2 platelet assessments ≥3 days apart before first dosing: mean platelet count <30×10⁹/L, no single value >35×10⁹/L.
  6. ECOG performance status 0-2.
  7. On stable-dose maintenance therapy for ≥4 weeks pre-first dose, with stability expected throughout the trial.

  8. Screening lab parameters meeting criteria below:

    1. Liver function: AST and ALT ≤3×ULN; total bilirubin ≤1.5×ULN.
    2. Renal function: eGFR ≥30 mL/min (CKD-EPI equation).
    3. CBC (no RBC transfusions, IL-11, EPO or colony-stimulating factors within 2 weeks before testing): hemoglobin ≥90 g/L, absolute neutrophil count ≥1.5×10⁹/L.
  9. Participants or partners with childbearing potential must use effective contraception during the study and for 6 months after last study drug administration.

Exclusion Criteria:

  1. Prior treatment targeting CD38, including but not limited to monoclonal antibodies, bispecific antibodies and antibody-drug conjugates.
  2. Secondary thrombocytopenia or concurrent autoimmune hemolytic anemia.
  3. History of thromboembolism within 12 months prior to randomization, or severe bleeding events (hemoptysis, massive gastrointestinal hemorrhage, intracranial hemorrhage, etc.).
  4. Anticoagulants or antiplatelet agents (e.g., aspirin) administered within 4 weeks before randomization.
  5. Emergency ITP therapies (methylprednisolone, platelet transfusion, IVIG, TPO-RA, etc.) received within 4 weeks before randomization.
  6. Oral immunosuppressants other than azathioprine, cyclosporine A and mycophenolate mofetil (e.g., tacrolimus, sirolimus) within 4 weeks pre-randomization; anti-CD20 mAbs (e.g., rituximab) within 3 months pre-randomization.
  7. Splenectomy performed within 6 months before randomization.
  8. Diagnosis of myelodysplastic syndrome; history of malignancy within 5 years pre-randomization (excluding cervical carcinoma in situ, basal cell skin carcinoma, etc.).
  9. Participation in another clinical trial within 4 weeks or 5 half-lives pre-randomization (whichever is longer), except placebo-controlled trials.
  10. History of severe recurrent or chronic infection; active systemic infection requiring IV antibiotics, antivirals, antiparasitics or antifungals within 4 weeks pre-randomization (excluding prophylaxis); acute infection; superficial skin infection within 1 week pre-randomization.
  11. Major surgery within 12 weeks pre-randomization, unhealed wounds, ulcers or fractures, or planned major surgery during the study.
  12. Severe cardiovascular or cerebrovascular diseases, including but not limited to: myocardial infarction, unstable angina or stroke within 6 months pre-randomization; NYHA Class III/IV heart failure; screening QTcF >480 ms or familial long QT syndrome; uncontrolled hypertension (resting SBP ≥160 mmHg and/or DBP ≥95 mmHg).
  13. HIV infection, active hepatitis B or hepatitis C.
  14. Confirmed active syphilis or Mycobacterium tuberculosis infection.
  15. Known hypersensitivity to monoclonal antibodies (prior Grade ≥3 allergic reactions per CTCAE v6.0) or excipients of investigational product.
  16. Live or attenuated live vaccines administered within 4 weeks pre-randomization or planned during the study.
  17. History of solid organ transplantation (heart, lung, kidney, liver, etc.) or hematopoietic stem cell/bone marrow transplantation.
  18. Lactating females.
  19. Any condition judged by the investigator to interfere with subject compliance or trial participation.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: SG301 SC Injection-low dose group
SG-301 SC monotherapy Weekly dosing for 8 doses
Drug: SG301 SC monotherapy low dose group
SG301 SC weekly for a total of 8 doses
Experimental: SG301 SC Injection-high dose group
SG-301 SC monotherapy Weekly dosing for 8 doses
Drug: SG301 SCmonotherapy high dose group
SG301 SC weekly for a total of 8 doses
Placebo Comparator: SG301 SC Placebo
Placebo SC monotherapy Weekly dosing for 8 doses
Drug: Placebo group
SG301 SC Placebo weekly for a total of 8 doses.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of Treatment-Emergent Adverse Events
Time Frame: up to 24 weeks
Number and percentage of AEs which is calculated by worst CTCAE grade by CTCAE 6
up to 24 weeks
ORR
Time Frame: at Week 8 of treatment
Overall platelet response rate
at Week 8 of treatment

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Hangzhou Sumgen Biotech Co., Ltd.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 11, 2026

Primary Completion (Estimated)

May 17, 2027

Study Completion (Estimated)

May 17, 2027

Study Registration Dates

First Submitted

July 9, 2026

First Submitted That Met QC Criteria

July 13, 2026

First Posted (Actual)

July 17, 2026

Study Record Updates

Last Update Posted (Actual)

July 17, 2026

Last Update Submitted That Met QC Criteria

July 13, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • CSG-301 SC-206

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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