A Prospective, Randomized, Open-Label, Parallel-Group Clinical Trial Evaluating the Efficacy and Safety of 125I Seed Interstitial Brachytherapy Combined With Immune Checkpoint Inhibitor Therapy in Patients With Primary, Recurrent, or Metastatic Malignant Tumors Compared With Immune Checkpoint Inhibitor Therapy Alone

NCT07277777 Phase 2 NOT_YET_RECRUITING

This prospective randomized trial evaluates the efficacy and safety of combining 125I seed interstitial brachytherapy with immune checkpoint inhibitor therapy in patients with primary, recurrent, or metastatic malignant tumors. Immunotherapy has become an important systemic treatment option, yet many patients experience limited benefit due to low tumor immunogenicity, insufficient T-cell infiltration, and an immunosuppressive tumor microenvironment. 125I seed brachytherapy provides continuous low-dose-rate radiation to the tumor, promoting antigen release, enhancing dendritic cell activation, and potentially converting immunologically "cold" tumors into more responsive "hot" lesions. Integrating localized radiation with systemic immunotherapy may improve tumor response, prolong progression-free survival, and reduce recurrence. Patients will be randomized 1:1 to receive 125I seed implantation plus immunotherapy or immunotherapy alone. The primary endpoints are objective response rate (ORR) and progression-free survival (PFS). Secondary endpoints include failure-free survival (FFS), overall survival (OS), disease control rate (DCR), duration of response (DoR), local control, recurrence rate, adverse events, and quality of life. Exploratory analyses will assess radiomics features, subgroup responses, and different patterns of recurrence. This study aims to determine whether adding 125I seed brachytherapy enhances the clinical benefits of immunotherapy across diverse malignant tumors.

Details

Lead sponsor	Li Min
Phase	Phase 2
Status	NOT_YET_RECRUITING
Enrolment	90
Start date	2026-01
Completion	2028-01-01

Conditions

• Malignant Tumors

Interventions

• Immune Checkpoint Inhibitors
• 125I Seed Implantation
• Immune Checkpoint Inhibitors

Primary outcomes

• Objective Response Rate (ORR) — Every 6-12 weeks, up to 24 months
  Proportion of patients achieving complete response (CR) or partial response (PR) as defined by RECIST 1.1 or iRECIST, assessed via CT/MRI/PET-CT.
• Progression-Free Survival (PFS) — Up to 24 months
  Time from randomization to radiographic disease progression or death from any cause.

Countries

China