Phase I Clinical Trial of CD19 CAR-T Cells Expressing CXCR5 Protein for the Treatment of Relapsed or Refractory B-cell Lymphoma.

Background: It is difficult for CD19 CAR-T cells to enter solid tumors, which is one reason for their poor efficacy in lymphoma treatment. The chemokine CXCL13 secreted by stro-mal cells of the lymph nodes induces the homing of B and T lymphocytes, which express its receptor CXCR5. Preclinical trials have shown that the expression of CXCR5 on CD19 CAR-T cells can increase their migration to the tumor microenvironment and enhance their antitumor function.

Methods: We engineered the CD19 CAR-T cells to express a second receptor, CXCR5. Then, we conducted a phase I clinical trial to evaluate the safety and efficacy of CXCR5 CD19 CAR-T cells in the treatment of relapsed or refractory (R/R) B-cell lymphoma.

Results: We recruited 10 patients with R/R B-cell lymphoma undergoing CXCR5 CD19 CAR-T cell therapy. The objective response rate was 80%, and the complete response rate was 50%. The median follow-up time was 15.48 months (3.4-22.3 months), and the median Progression-Free Survival (PFS) time was 8.15 months (1.5-22.33 months). One patient received ASCT at 1.5 months (at PR) after infusion of CAR-T cells. The incidence of grade 1 and grade 2 Cytokine Release Syndrome (CRS) was 70% and 20%, respectively. No patient experienced grade 3 or higher levels of CRS, neurotoxicity, or infusion-related dose toxicity.

Conclusion: The results obtained in this study suggest that CXCR5 CD19 CAR-T cells should be investigated in a trial with broader patient populations.

Trial registration: The trials were registered at www.chictr.org.cn as ChiCTR2100052677 and ChiCTR1900028692.