Radiation Combined With BCMA/CD3 Bispecific Antibody Therapy for Solitary Bone Plasmacytoma With Mild Bone Marrow Infiltration

NCT ID: NCT07115667

Last Updated: 2025-09-08

Basic Information

• Recruitment Status: RECRUITING
• Clinical Phase: PHASE2
• Total Enrollment: 21 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-08-25
• Study Completion Date: 2027-12-01

Brief Summary

This is a prospective, single-arm, single-center clinical trial designed to evaluate the safety and efficacy of radiation combined with a BCMA/CD3 bispecific antibody (CM336) in patients with solitary bone plasmacytoma (SBP) with mild bone marrow infiltration.

Detailed Description

This is a prospective, single-arm, single-center clinical trial designed to evaluate the safety and efficacy of radiation combined with a BCMA/CD3 bispecific antibody (CM336) in patients with solitary bone plasmacytoma (SBP) with mild bone marrow infiltration. SBP is a rare plasma cell malignancy with a high risk of progression to multiple myeloma (MM), particularly in patients with minimal bone marrow involvement.

Although radiotherapy is the standard treatment, it is often insufficient to eradicate clonal plasma cells and prevent progression in high-risk patients. CM336, a novel BCMA/CD3 bispecific antibody, has demonstrated promising activity in relapsed/refractory multiple myeloma. In this trial, eligible patients will receive radiotherapy followed by a 12-cycle limited treatment course of CM336, aiming to achieve deep clearance of residual malignant cells and reduce progression risk.

Conditions

Solitary Bone Plasmacytoma; Plasmacytoma of Bone; Plasma Cell Disorders

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

BsAbs-treatment group

Patients with solitary bone plasmacytoma (SBP) with mild bone marrow infiltration will receive radiation combined with a BCMA/CD3 bispecific antibody (CM336)

Group Type: EXPERIMENTAL

BCMA/CD3 bispecific antibody (CM336)

Intervention Type: DRUG

Patients with solitary bone plasmacytoma (SBP) with mild bone marrow infiltration will receive radiation combined with a BCMA/CD3 bispecific antibody (CM336)

Interventions

BCMA/CD3 bispecific antibody (CM336)

Patients with solitary bone plasmacytoma (SBP) with mild bone marrow infiltration will receive radiation combined with a BCMA/CD3 bispecific antibody (CM336)

Intervention Type: DRUG

Eligibility Criteria

Inclusion Criteria

• ≥18 years old
• Histologically confirmed SBP with <10% clonal plasma cells in marrow
• ECOG ≤ 2
• No prior anti-myeloma therapy. Previous local radiotherapy for SBP is not an exclusion criterion.
• Meets laboratory and imaging criteria

Exclusion Criteria

1. Patients who have previously received anti-plasma cell therapy, including melphalan, cyclophosphamide, proteasome inhibitors, immunomodulatory drugs, monoclonal antibodies, bispecific antibodies, or chimeric antigen receptor T-cell (CAR-T) therapy.

2. Any condition that, in the opinion of the investigator, would make the patient unsuitable for participation in this study.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 78 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Institute of Hematology & Blood Diseases Hospital, China

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

Institute of Hematology and Blood Diseases Hospital Chinese Academy of Medical Sciences

Tianjin, , China

Site Status: RECRUITING

Countries

China

Central Contacts

Gang An, MD

Role: CONTACT

angang@ihcams.ac.cn

13502181109

Facility Contacts

Gang An, PhD&MD

Role: primary

angang@ihcams.ac.cn

008613502181109

Other Identifiers

IIT2025065

Identifier Type: -

Identifier Source: org_study_id