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

NCT07710248 | Recruiting Phase 2

• 1 other identifier: CSG-301 SC-206
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 22

Brief Summary

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.

Conditions

Primary Immune Thrombocytopenia

Outcome Measures

Primary Outcomes (2)

• Incidence of Treatment-Emergent Adverse Events

  Number and percentage of AEs which is calculated by worst CTCAE grade by CTCAE 6

  up to 24 weeks

• ORR

  Overall platelet response rate

  at Week 8 of treatment

Study Arms (3)

SG301 SC Injection-low dose group

EXPERIMENTAL

SG-301 SC monotherapy Weekly dosing for 8 doses

Drug: low dose group

SG301 SC Injection-high dose group

EXPERIMENTAL

SG-301 SC monotherapy Weekly dosing for 8 doses

Drug: high dose group

SG301 SC Placebo

PLACEBO COMPARATOR

Placebo SC monotherapy Weekly dosing for 8 doses

Drug: Placebo group

Interventions

Placebo group DRUG

SG301 SC Placebo weekly for a total of 8 doses, subcutaneous injection

SG301 SC Placebo

low dose group DRUG

SG301 SC weekly for a total of 8 doses, subcutaneous injection

SG301 SC Injection-low dose group

high dose group DRUG

SG301 SC weekly for a total of 8 doses , subcutaneous injection

SG301 SC Injection-high dose group

Eligibility Criteria

• Age: 18 Years - 75 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Aged 18-75 years, any gender.
• Voluntarily signed informed consent and able to comply with study procedures.
• 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.
• Experienced treatment failure or relapse after prior first-line therapy (glucocorticoids and/or IVIG).
• ≥2 platelet assessments ≥3 days apart before first dosing: mean platelet count \<30×10⁹/L, no single value \>35×10⁹/L.
• ECOG performance status 0-2.
• On stable-dose maintenance therapy for ≥4 weeks pre-first dose, with stability expected throughout the trial.
• Screening lab parameters meeting criteria below:
• Liver function: AST and ALT ≤3×ULN; total bilirubin ≤1.5×ULN.
• Renal function: eGFR ≥30 mL/min (CKD-EPI equation).
• 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.
• Participants or partners with childbearing potential must use effective contraception during the study and for 6 months after last study drug administration.

You may not qualify if:

• Prior treatment targeting CD38, including but not limited to monoclonal antibodies, bispecific antibodies and antibody-drug conjugates.
• Secondary thrombocytopenia or concurrent autoimmune hemolytic anemia.
• History of thromboembolism within 12 months prior to randomization, or severe bleeding events (hemoptysis, massive gastrointestinal hemorrhage, intracranial hemorrhage, etc.).
• Anticoagulants or antiplatelet agents (e.g., aspirin) administered within 4 weeks before randomization.
• Emergency ITP therapies (methylprednisolone, platelet transfusion, IVIG, TPO-RA, etc.) received within 4 weeks before randomization.
• 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.
• Splenectomy performed within 6 months before randomization.
• Diagnosis of myelodysplastic syndrome; history of malignancy within 5 years pre-randomization (excluding cervical carcinoma in situ, basal cell skin carcinoma, etc.).
• Participation in another clinical trial within 4 weeks or 5 half-lives pre-randomization (whichever is longer), except placebo-controlled trials.
• 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.
• Major surgery within 12 weeks pre-randomization, unhealed wounds, ulcers or fractures, or planned major surgery during the study.
• 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).
• HIV infection, active hepatitis B or hepatitis C.
• Confirmed active syphilis or Mycobacterium tuberculosis infection.
• Known hypersensitivity to monoclonal antibodies (prior Grade ≥3 allergic reactions per CTCAE v6.0) or excipients of investigational product.

Sponsors & Collaborators

• Hangzhou Sumgen Biotech Co., Ltd.: lead

Study Sites (22)

Fujian Medical University Union Hospital

Fuzhou, Fujian, 350001, China

RECRUITING

Nanfang Hospital, Southern Medical University

Guangzhou, Guangdong, 510515, China

NOT YET RECRUITING

Liuzhou People's Hospital

Liuzhou, Guangxi, 545006, China

NOT YET RECRUITING

Yulin Red Cross Hospital

Yulin, Guangxi, 537000, China

RECRUITING

Hebei University Affiliated Hospital

Baoding, Hebei, 071000, China

NOT YET RECRUITING

Affiliated Hospital of Chengde Medical University

Chengde, Hebei, 067000, China

NOT YET RECRUITING

North China University of Science and Technology Affiliated Hospital

Tangshan, Hebei, 063000, China

RECRUITING

The Second Affiliated Hospital of Harbin Medical University

Harbin, Heilongjiang, 150086, China

RECRUITING

Pingdingshan First People's Hospital

Pingdingshan, Henan, 467000, China

RECRUITING

Henan Cancer Hospital

Zhenzhou, Henan, 450003, China

NOT YET RECRUITING

Union Hospital, Tongji Medical College, Huazhong University of Science and Technology

Wuhan, Hubei, 430022, China

NOT YET RECRUITING

Xiangyang Central Hospital

Xiangyang, Hubei, 441021, China

NOT YET RECRUITING

Siping Central People's Hospital

Siping, Jilin, 136000, China

RECRUITING

The First Affiliated Hospital of Shandong First Medical University (Qianfoshan Hospital)

Jinan, Shandong, 250014, China

RECRUITING

Jining No.1 People's Hospital

Jining, Shandong, 272011, China

RECRUITING

Heping Hospital Affiliated to Changzhi Medical College

Changzhi, Shanxi, 046000, China

RECRUITING

The Second Affiliated Hospital of Xi'an Jiaotong University

Xian, Shanxi, China, China

RECRUITING

West China Hospital, Sichuan University

Chengdu, Sichuan, 610041, China

NOT YET RECRUITING

Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences

Tianjin, Tianjin Municipality, 300020, China

RECRUITING

Yunnan Provincial First People's Hospital

Kunming, Yunnan, 650032, China

RECRUITING

The First Affiliated Hospital, Zhejiang University School of Medicine

Hangzhou, Zhejiang, 310003, China

RECRUITING

The First Affiliated Hospital of Wenzhou Medical University

Wenzhou, Zhejiang, 325000, China

RECRUITING

MeSH Terms

Conditions

Purpura, Thrombocytopenic, Idiopathic

Interventions

Population Groups

Condition Hierarchy (Ancestors)

Purpura, Thrombocytopenic; Purpura; Blood Coagulation Disorders; Hematologic Diseases; Hemic and Lymphatic Diseases; Thrombotic Microangiopathies; Thrombocytopenia; Blood Platelet Disorders; Cytopenia; Hemorrhagic Disorders; Autoimmune Diseases; Immune System Diseases; Hemorrhage; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Skin Manifestations; Signs and Symptoms

Intervention Hierarchy (Ancestors)

Demography; Population Characteristics

Central Study Contacts

Songping Ao

CONTACT

86-0571-86035537; aosongping@sumgenbio.com

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: July 9, 2026
• First Posted: July 17, 2026
• Study Start: June 11, 2026
• Primary Completion (Estimated): May 17, 2027
• Study Completion (Estimated): May 17, 2027
• Last Updated: September 9, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

CN (22)