Jing Pan, Yue Tan, Lingling Shan, Samuel Seery, Biping Deng, Zhuojun Ling, Jinlong Xu, Jiajia Duan, Zelin Wang, Kai Wang, Xinjian Yu, Qinlong Zheng, Xiuwen Xu, Guang Hu, Taochao Tan, Ying Yuan, Zhenglong Tian, Fangrong Yan, Yajing Han, Jiecheng Zhang & Xiaoming Feng

Abstract

Refractory or relapsed T cell acute lymphoblastic leukemia (r/r T-ALL) patients have poor prognoses, due to the lack of effective salvage therapies. Recently, CD7-targeting chimeric antigen receptor (CAR)-T therapies show efficacy in patients with r/r T-ALL, but relapse with CD7 loss is common. This study evaluates a CD5-gene-edited CAR-T cell therapy targeting CD5 in 19 r/r T-ALL patients, most of whom had previously failed CD7 CAR-T interventions. CAR-T products were derived from previous transplant donors (Cohort A) or newly matched donors (Cohort B). Primary endpoints were dose-limiting toxicity at 21 days and adverse events within 30 days. Secondary endpoints were responses, pharmacokinetics and severe adverse events after 30 days. A total of 16 received infusions, 10 at target dose of 1 × 10⁶ kg⁻¹. All encountered grade 3–4 cytopenias and one had a grade 3 infection within 30 days. All patients (100%) achieved complete remission or complete remission with incomplete blood count recovery by day 30. At a median follow-up of 14.3 months, four received transplantation; three were in remission and one died of infection. Of 12 untransplanted patients, 2 were in remission, 3 relapsed, 5 died of infection and 2 of thrombotic microangiopathy. CAR-T cells persisted and cleared CD5⁺ T cells. CD5⁻ T cells, mostly CD5-gene-edited, increased but remained below normal levels. These results suggest this CD5-specific CAR-T intervention has a high remission rate for T-ALL patients. Evidence also suggests the risk of late-onset severe infection may be mitigated with consolidative transplantation. This study provides insights that could help to optimize this promising intervention.

Refer to the original: https://doi.org/10.1038/s41591-024-03282-2