A Clinical Study Comparing SG301 Plus Pomalidomide and Dexamethasone to Placebo Plus Pomalidomide and Dexamethasone in Relapsed or Refractory Multiple Myeloma Patients

A Phase 3 Randomized, Placebo-controlled, Double-blind, Multicenter Study Comparing SG301 in Combination With Pomalidomide and Dexamethasone Versus Placebo in Combination With Pomalidomide and Dexamethasone in Patients With Relapsed or Refractory Multiple Myeloma

The purpose of this study is to evaluate the effects of the addition of SG301 injection to pomalidomide and dexamethasone in subjects with relapsed or refractory multiple myeloma.

Study Overview

• Status: Recruiting
• Conditions: Relapsed/Refractory Multiple Myeloma
• Intervention / Treatment: Drug: SG301 Injection; Drug: pomalidomide; Drug: dexamethasone; Drug: SG301 placebo

Detailed Description

This is a randomized, placebo-controlled, double-blind, multicenter phase III clinical study to compare SG301 injection in combination with pomalidomide and dexamethasone versus placebo in combination with pomalidomide and dexamethasone in patients with relapsed or refractory multiple myeloma who have received at least 1 prior treatment regimen with both lenalidomide and a proteasome inhibitor and have demonstrated disease progression.

This study consists of two stages. Stage 1 is the dose exploration stage to confirm the recommended stage 2 dose of SG301 injection in combination with pomalidomide and dexamethasone in patients with relapsed/refractory multiple myeloma. Stage 2 is the randomized controlled stage of SG301 injection in combination with pomalidomide and dexamethasone versus placebo in combination with pomalidomide and dexamethasone in patients with relapsed/refractory multiple myeloma.

• Study Type: Interventional
• Enrollment (Estimated): 360
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Jing Yang; Phone Number: +86 010-56315401; Email: yangjing@sumgenbio.com

Study Locations

• China
  • Beijing
    • Beijing, Beijing, China, 100024
      • Recruiting
      • Beijing Chaoyang Hospital of Capital Medical University
      • Contact: Wenming Chen, Doctor
      • Contact: Ying Tian
  • Guangdong
    • Guangzhou, Guangdong, China, 510000
      • Not yet recruiting
      • Sun yat-sen University Cancer Center
      • Contact: Zhongjun Xia
      • Contact: Xiaoqin Chen
    • Guangzhou, Guangdong, China, 510000
      • Not yet recruiting
      • Guangzhou First People's Hospital
      • Contact: Shunqing Wang
      • Contact: Wei Zhou
  • Henan
    • Luoyang, Henan, China, 471000
      • Recruiting
      • First Affiliated Hospital of Henan University of Science and Technology
      • Contact: haiping Yang
      • Contact: Bingke Zhu
    • Zhengzhou, Henan, China, 450000
      • Recruiting
      • Henan Cancer Hospital
      • Contact: Baijun Fang
      • Contact: Yuzhang Liu
  • Hubei
    • Wuhan, Hubei, China, 430000
      • Recruiting
      • Union Hospital, Tongji Medical College, Huazhong University of Science and Technology
      • Contact: Chunyan Sun
      • Contact: Fei Zhao
  • Jiangsu
    • Suzhou, Jiangsu, China, 215006
      • Recruiting
      • the First Affiliated Hospital of Soochow University
      • Contact: ZhengZheng Fu
      • Contact: Yingying Zhai
  • Shanxi
    • Taiyuan, Shanxi, China, 030000
      • Recruiting
      • Shanxi Provincial Hospital
      • Contact: Liping Su
      • Contact: Jingrong Wang
    • Xi'an, Shanxi, China, 710000
      • Recruiting
      • The Second Affiliated Hospital Of Xi an Jiaotong University (Xibei Hospital)
      • Contact: Wanhong Zhao
      • Contact: Fangxia Wang
  • Tianjin
    • Tianjin, Tianjin, China, 300060
      • Not yet recruiting
      • Tianjin Medical University Cancer Institute & Hospital
      • Contact: Yafei Wang
      • Contact: Haifeng Zhao
    • Tianjin, Tianjin, China, 300060
      • Recruiting
      • Tianjin Cancer University Airport Hospital
      • Contact: Yafei Wang
      • Contact: Zhiying Zhang
  • Zhejiang
    • Hangzhou, Zhejiang, China, 310056
      • Recruiting
      • the Second Affiliated Hospital Zhejiang University School of Medicine
      • Contact: WenBin Qian
      • Contact: Xuzhao Zhang

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

1. Understand and voluntarily sign the informed consent form (ICF).
2. Males and females aged 18-75 years (inclusive)
3. Eastern Cooperative Oncology Group (ECOG) Performance Status score of 0, 1 or 2
4. Expected survival time of ≥3 months.
5. Subjects had a documented diagnosis of multiple myeloma with evidence of measurable disease.
6. Subjects had received at least 1 prior lines of anti-myeloma therapy, which must include lenalidomide and a proteasome inhibitor (bortezomib, carfilzomib or ixazomib) given alone or in combination.
7. Subjects must have documented evidence of PD on or after the last regimen.
8. Adequate function of vital organs
9. Women of childbearing potential (WOCBP) must agree to follow instructions for methods of contraception for 4 weeks before the start of study treatment, for the duration of study treatment, and for 6 months after cessation of SG301 or 4 weeks after cessation of pomalidomide, whichever is longer. WOCBP must have 2 negative serum or urine pregnancy tests, one 10-14 days prior to start of study treatment and one 24 hours prior to the start of study treatment.

Exclusion Criteria:

1. Primary refractory multiple myeloma defined as participants who had never achieved at least a minimal response (MR) with any treatment during the disease course.
2. Bone independent extramedullary disease at screening.
3. Subjects who are primary refractory to a prior CD38 monoclonal antibody therapy.
4. Previous exposure to pomalidomide.
5. Subject has received chemotherapy or small molecule antitumor therapy within 2 weeks or 5 pharmacokinetic half-lives of the treatment, whichever is shorter, before the first dose of study treatment;
6. Subject has received tumor biotherapy within 4 weeks or 5 pharmacokinetic half-lives of the treatment, whichever is shorter, before the first dose of study treatment;
7. Subject has received investigational agents within 4 weeks or 5 pharmacokinetic half-lives of the treatment, whichever is shorter (but not less than 14 days), before the first dose of study treatment;
8. Active hepatitis B, or C.
9. Known HIV infection.
10. Known active tuberculosis or positive treponema pallidum antibodies.
11. Subjects with clinical significant organ dysfunction that does not meet the study needs.
12. Previous allogenic stem cell transplant or autologous stem cell transplantation (ASCT) before the first dose of study treatment.
13. Known allergy to any component of the investigational medicinal product.
14. Any concurrent medical or psychiatric condition or disease (eg, active systemic infection, uncontrolled diabetes, acute diffuse infiltrative pulmonary disease) that is likely to interfere with the study procedures or results or that, in the opinion of the investigator, would constitute a hazard for participating in this study.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: SG301 Injection in combination with pomalidomide and dexamethasone; Participants will receive SG301 Injection in combination with pomalidomide and dexamethasone. Treatment cycles have a duration of 28 days. Participants will continue to receive study treatment until confirmed disease progression, unacceptable toxicity, or any other treatment discontinuation criteria are met.	Drug: SG301 Injection; Dosage form: solution for infusion Route of administration: intravenous Frequency: weekly intervals (QW) for 8 weeks, then every 2 weeks (Q2W) thereafter.; Drug: pomalidomide; Dosage form: capsule Route of administration: oral Dosage: 4 mg Frequency: once daily on Days 1 through 21 of each 28-day cycle.; Drug: dexamethasone; Dosage form: tablets or solution for infusion Route of administration: oral or intravenous Dosage: 40 mg (participants with BMI < 18.5 kg/m2 received 20 mg dexamethasone) Frequency: once daily on Day 1, 8, 15, 22 of each 28-day treatment cycle.
Placebo Comparator: Placebo in combination with pomalidomide and dexamethasone; Participants in Stage 2 who randomized to this arm will receive placebo in combination with pomalidomide and dexamethasone. Treatment cycles have a duration of 28 days. Participants will continue to receive study treatment until confirmed disease progression, unacceptable toxicity, or any other treatment discontinuation criteria are met.	Drug: pomalidomide; Dosage form: capsule Route of administration: oral Dosage: 4 mg Frequency: once daily on Days 1 through 21 of each 28-day cycle.; Drug: dexamethasone; Dosage form: tablets or solution for infusion Route of administration: oral or intravenous Dosage: 40 mg (participants with BMI < 18.5 kg/m2 received 20 mg dexamethasone) Frequency: once daily on Day 1, 8, 15, 22 of each 28-day treatment cycle.; Drug: SG301 placebo; Dosage form: solution for infusion Route of administration: intravenous Frequency: weekly intervals (QW) for 8 weeks, then every 2 weeks (Q2W) thereafter.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Adverse events （stage 1）	AEs, DLTs, laboratory abnormality, Vital signs or ECG abnormalities, ECOG scores, abnormal physical examination	From date of first dose of study intervention through approximately 30 days after last study intervention administration, assessed up to approximately 4 years.
Recommended stage 2 dose of SG301 (Stage 1)	Recommended stage 2 dose of SG301 will be determined based on the DLTs and safety data	Up to approximately 6 months.
Progression Free Survival (Stage 2)	Comparison of Progression Free Survival between treatment arms (SG301/Pomalidomide/Dexamethasone vs Placebo/Pomalidomide/Dexamethasone).	From baseline through the end of study. Assessed every 4 weeks after randomization until C19D1, and every 8 weeks thereafter until disease progression (IMWG criteria) or death whichever occurs first, assessed up to approximately 4 years.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pharmacokinetics (PK): AUC	The area under the curve (AUC) of serum concentration of the drug after the administration.	From date of first dose of study intervention through approximately 30 days after last study intervention administration, assessed up to approximately 4 years.
Pharmacokinetics (PK): Cmax	Cmax to maximum drug concentration.	From date of first dose of study intervention through approximately 30 days after last study intervention administration, assessed up to approximately 4 years.
Pharmacokinetics (PK):limination half-life (T1/2)	Limination half-life (T1/2) of the drug after administration.	From date of first dose of study intervention through approximately 30 days after last study intervention administration, assessed up to approximately 4 years.
Overall Response Rate	ORR (IMWG criteria): percentage of participants with stringent complete response(sCR), complete response (CR), very good partial response (VGPR), and partial response (PR) as best overall response	From baseline through the end of study. It is measured from the start of treatment until disease progression, death, initiation of further anti-myeloma treatment, or cut-off date, whichever occurs first, assessed up to approximately 4 years.
Percentage of Participants With Very Good Partial Response (VGPR) or Better (≥VGPR Rate)	≥VGPR Rate (IMWG criteria): percentage of participants with stringent complete response(sCR), complete response (CR), and very good partial response (VGPR) as best overall response.	From baseline through the end of study. It is measured from the start of treatment until disease progression, death, initiation of further anti-myeloma treatment, or cut-off date, whichever occurs first, assessed up to approximately 4 years.
Duration of Response	Duration of response will be restricted to subjects who achieve a best objective response of PR or better.	From baseline through the end of study. It is measured from the time that the criteria for objective response are first met until the date of a progression event, assessed up to approximately 4 years.
Overall Survival	Overall survival is defined as the time, in months, from randomization to the date of death from any cause.	From baseline through the end of study, assessed up to approximately 4 years.
Percentage of Participants With Minimal Residual Disease (MRD)	MRD was assessed by next-generation sequencing in bone marrow samples from participants who achieved CR or sCR, to determine the depth of response at the molecular level.	From baseline through the end of study. It is measured from the time that the criteria for CR are first met until the date of a progression event, assessed up to approximately 4 years.
Immunogenicity endpoints	Anti-SG301 antibody, neutralizing antibody (to be detected only in case of the presence of anti-SG301 antibody.	From date of first dose of study intervention through approximately 30 days after last study intervention administration, assessed up to approximately 4 years.

Collaborators and Investigators

• Sponsor: Hangzhou Sumgen Biotech Co., Ltd.

Study record dates

Study Major Dates

• Study Start (Actual): June 14, 2024
• Primary Completion (Estimated): March 31, 2027
• Study Completion (Estimated): March 31, 2028

Study Registration Dates

• First Submitted: July 5, 2024
• First Submitted That Met QC Criteria: July 17, 2024
• First Posted (Actual): July 19, 2024

Study Record Updates

• Last Update Posted (Actual): June 27, 2025
• Last Update Submitted That Met QC Criteria: June 24, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Neoplasms; Immune System Diseases; Neoplasms by Histologic Type; Hematologic Diseases; Lymphoproliferative Disorders; Immunoproliferative Disorders; Hemostatic Disorders; Paraproteinemias; Blood Protein Disorders; Hemorrhagic Disorders; Multiple Myeloma; Neoplasms, Plasma Cell; Antineoplastic Agents; Immunologic Factors; Physiological Effects of Drugs; Anti-Inflammatory Agents; Antiemetics; Autonomic Agents; Peripheral Nervous System Agents; Gastrointestinal Agents; Glucocorticoids; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Antineoplastic Agents, Hormonal; Angiogenesis Inhibitors; Angiogenesis Modulating Agents; Growth Substances; Growth Inhibitors; Dexamethasone; Pomalidomide
• Other Study ID Numbers: CSG-301-301

Drug and device information, study documents

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