A Study to Evaluate the Safety and Efficacy of SCTB35 in Combination With Gemcitabine and Oxaliplatin in Patients With Relapsed or Refractory Diffuse Large B-Cell Lymphoma

A Phase 3 Randomized, Open-label, Multicenter Study to Evaluate the Safety and Efficacy of SCTB35 in Combination With Gemcitabine and Oxaliplatin Versus Rituximab in Combination With Gemcitabine and Oxaliplatin in Patients With Relapsed or Refractory Diffuse Large B-Cell Lymphoma

The purpose of this study is to evaluate the efficacy and safety of SCTB35 in Combination With Gemcitabine and Oxaliplatin vs Rituximab in Combination With Gemcitabine and Oxaliplatin in Patients With Relapsed or Refractory Diffuse Large B-Cell Lymphoma.

Study Overview

• Status: Not yet recruiting
• Conditions: DLBCL - Diffuse Large B Cell Lymphoma
• Intervention / Treatment: Drug: Rituxumab; Drug: SCTB35 injection; Drug: Gemcitabine; Drug: Oxaliplatin

• Study Type: Interventional
• Enrollment (Estimated): 101
• Phase: Phase 3

Contacts and Locations

Study Locations

• China
  • Beijing, China, 100142
    • Beijing Cancer Hospital

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Age 18-80 years old
• Histologically confirmed diffuse large B-cell lymphoma according to WHO 2022 criteria
• Relapsed or refractory (R/R) disease following at least one prior systemic regimen that contained an anti-CD20 monoclonal antibody (mAb) in combination with chemotherapy
• Participants who have failed after one prior line of therapy are not candidates for high-dose chemotherapy followed by autologous stem cell transplant (ASCT)
• Presence of measurable or evaluable disease at baseline ECOG PS 0-2
• ECOG PS 0-2
• Adequate organ function and bone marrow function
• Expected survival ≥ 3 months

Exclusion Criteria:

• Prior treatment with antibodies targeting both CD20 and CD3
• Contraindication to rituximab, gemcitabine or oxaliplatin, or prior treatment with an anti-CD20 antibody in combination with the GemOx regimen
• Peripheral neuropathy assessed to be Grade >1 according to National Cancer Institute Common Terminology Criteria for Adverse Events (NCI CTCAE) v6.0 at enrollment
• Known central nervous system (CNS) involvement by lymphoma
• Known any major episode of active infection requiring treatment with systemic antibiotics within 2 weeks
• Treatment with chimeric antigen receptor T-cell (CAR-T) therapy within 100 days prior to first SCTB35 administration
• Autologous HSCT within 100 days prior to first SCTB35 administration, or any prior allogeneic HSCT or solid organ transplantation
• Major surgery within 4 weeks prior to first SCTB35 administration
• Chemotherapy and other non-investigational antineoplastic agents (except CD20 mAbs) within 4 weeks or 5 half-lives (whichever is shorter) prior to first SCTB35 administration
• Administration of a live, attenuated vaccine within 4 weeks before first study treatment administration or anticipation that such a live, attenuated vaccine will be required during the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: R-GemOx	Drug: Rituxumab; Participants will receive IV rituxumab on Day 1 of each cycle for up to 8 cycles.; Drug: Gemcitabine; Participants will receive IV gemcitabine administration for up to 8 cycles.; Drug: Oxaliplatin; Participants will receive IV oxaliplatin administration for up to 8 cycles.
Experimental: SCTB35-GemOx	Drug: SCTB35 injection; SCTB35 will be subcutaneously administered at a dose as specified; Drug: Gemcitabine; Participants will receive IV gemcitabine administration for up to 8 cycles.; Drug: Oxaliplatin; Participants will receive IV oxaliplatin administration for up to 8 cycles.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Adverse Events	Treatment-emergent adverse events/serious adverse events/adverse events of special interest	Up to approximately 3 years
Progression free survival (PFS)	Defined as the time from the date of randomization to the date of first documentation of progression disease (PD) or the date of death from any cause, whichever occurs first.	Up to approximately 3 years

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants Achieving Best Overall Response (BOR)	BOR is defined as Complete Response (CR) or Partial Response (PR), determined by Lugano criteria	Up to approximately 3 years
Percentage of Participants Achieving CR	Percentage of participants who achieve a CR determined per Lugano criteria.	Up to approximately 3 years
Overall Survival (OS)	Overall survival is defined as the duration from the date of randomization to the date of the participant's death.	Up to approximately 3 years
Duration of Response (DOR)	DOR is defined as the time from the first occurrence of response (CR or PR) to disease progression or death, whichever occurs first.	Up to approximately 3 years
Time to Response (TTR)	Time to response is defined for participants achieving a CR/PR as the time from starting therapy to first a CR/PR.	Up to approximately 3 years
Event-Free Survival (EFS)	EFS is defined as the duration from randomization to disease progression determined by Lugano criteria as assessed by the investigator, initiation of any non-protocol-specified new anti-lymphoma therapy for any reason, or death (whichever occurs first).	Up to approximately 3 years
Duration of Complete Response (DOCR)	DOCR is defined as the time from the first occurrence of CR to disease progression or death, whichever occurs first.	Up to approximately 3 years
Time to Complete Response (TTCR)	Time to complete response is defined for participants achieving a CR as the time from starting therapy to first a CR.	Up to approximately 3 years
Blood Concentrations of SCTB35	The pharmacokinetics of SCTB35 will be analyzed based on the drug concentrations at respective timepoints in the blood samples (or blood derivative)	Up to approximately 1 years
Anti-drug Antibodies of SCTB35	Blood samples (or blood derivative) will be screened for antibodies binding to SCTB35	Up to approximately 3 years

Collaborators and Investigators

• Sponsor: Sinocelltech Ltd.

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2026
• Primary Completion (Estimated): November 1, 2027
• Study Completion (Estimated): April 1, 2029

Study Registration Dates

• First Submitted: April 29, 2026
• First Submitted That Met QC Criteria: April 29, 2026
• First Posted (Actual): May 6, 2026

Study Record Updates

• Last Update Posted (Actual): May 6, 2026
• Last Update Submitted That Met QC Criteria: April 29, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neoplasms; Neoplasms by Histologic Type; Lymphatic Diseases; Histiocytic Disorders, Malignant; Histiocytosis; Hemic and Lymphatic Diseases; Dendritic Cell Sarcoma, Interdigitating; Organic Chemicals; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Coordination Complexes; Deoxycytidine; Cytidine; Pyrimidine Nucleosides; Pyrimidines; Oxaliplatin; Gemcitabine
• Other Study ID Numbers: SCTB35-B301

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