NCT07212335

Safety and Efficacy of Umbilical Cord Blood-Derived Mesenchymal Stem Cells in the Treatment of Long-Term Cytopenia After CAR-T Therapy

Single-Arm, Exploratory Clinical Study to Evaluate the Safety and Efficacy of Umbilical Cord Blood-Derived Mesenchymal Stem Cells in the Treatment of Long-Term Cytopenia After CAR-T Therapy

• Status: Recruiting
• Phase: EARLY_Phase 1
• Study type: Interventional
• Enrollment: 15 (estimated)
• Sponsor: Institute of Hematology & Blood Diseases Hospital, China · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

Summary

This study is a single arm, open label, exploratory clinical study aimed at evaluating the efficacy, and safety of allogeneic umbilical cord blood-derived mesenchymal stem cells in the treatment of long-term cytopenia after CAR-T therapy.

Detailed description

This is a single-center, open-label, dose-escalation exploratory trial, whose primary objective is to evaluate the safety and preliminary efficacy of human umbilical cord-derived mesenchymal stem cell injection in patients with acute lymphoblastic leukemia, lymphoma, and multiple myeloma who still suffer from severe cytopenia 3 weeks after CAR-T infusion, so as to provide dose evidence and efficacy reference for subsequent studies. Targeting the severe cytopenia complication with a high incidence rate (27%-95%) after CAR-T therapy and limited efficacy of conventional treatments, this trial adopts a "3+3" dose-escalation design. All three groups use a unified single dose of 2×10⁶ cells/kg body weight, differing only in infusion frequency (Group A: once; Group B: twice; Group C: four times), with 3 patients initially enrolled in each group. The dose-limiting toxicity (DLT) observation period is 28 days; if 2 or more DLTs occur, dose escalation will be terminated. The total sample size ranges from 15 to 24 cases, with a 24-week follow-up (weekly for the first 8 weeks and monthly from week 9 to week 24). Cell Preparation: Dispensed according to the actual body weight of each subject at a standard dose of 2×10⁶ cells/kg body weight, in compliance with GMP requirements. The cell viability is ≥85%, and the preparation can only be released after passing pathogenic microorganism, purity and tumorigenicity screenings. Infusion Procedure: Administer 5mg dexamethasone 30 minutes before infusion to prevent allergies. Thaw and mix the preparation at room temperature before infusion, with an initial rate of 20 drops/min for the first 15 minutes; if no discomfort occurs, adjust the rate to 40-60 drops/min (completing the infusion within 30-60 minutes). Monitor vital signs every 15 minutes during infusion and keep the patient under observation for 2 hours after infusion. Safety: Graded according to NCI CTCAE 5.0. Acute reactions are monitored for 24 hours, delayed reactions are specifically examined at weeks 4, 8, 12 and 24, and serious adverse events (SAEs) must be reported within 24 hours. Efficacy: Complete response (CR) and partial response (PR) require "dual-test compliance + 7 days without blood product transfusion" (with an interval of ≥48 hours). The response rate and duration are calculated at weeks 4 and 8 as key time points. Immunological Detection: Collect samples at baseline and at weeks 1, 4 and 8 after infusion to detect inflammatory markers, immune cells and cytokines.

Conditions

• Immune Effector Cell Associated Hematotoxicity

Interventions

Type	Name	Description
BIOLOGICAL	Mesenchymal Stem Cell Infusion	Mesenchymal stem cells: intravenous infusion, 2×10⁶ cells/kg body weight/week (once weekly), with 1 to 4 administrations based on different dosage groups.

Timeline

• Start date: 2025-10-01
• Primary completion: 2027-09-30
• Completion: 2028-09-30
• First posted: 2025-10-08
• Last updated: 2026-02-11

Locations

1 site across 1 country: China