AUTHOR=Hu Guan-hua , Cheng Yi-fei , Zuo Ying-xi , Chang Ying-jun , Suo Pan , Wu Jun , Jia Yue-ping , Lu Ai-dong , Li Ying-chun , Wang Yu , Jiao Shun-chang , Zhang Long-ji , Zhao Xiang-yu , Yan Chen-hua , Xu Lan-ping , Zhang Xiao-hui , Liu Kai-yan , Wang Yu , Zhang Le-ping , Huang Xiao-jun 

TITLE=Chimeric Antigens Receptor T Cell Therapy Improve the Prognosis of Pediatric Acute Lymphoblastic Leukemia With Persistent/Recurrent Minimal Residual Disease in First Complete Remission

JOURNAL=Frontiers in Immunology

VOLUME=Volume 12 - 2021

YEAR=2022

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2021.731435

DOI=10.3389/fimmu.2021.731435

ISSN=1664-3224

ABSTRACT=Background The presence of minimal residual disease (MRD) is an independent risk factor for poor prognosis in patients with acute lymphoblastic leukemia (ALL). Moreover, the role of chimeric antigen receptor T-cell (CAR-T) therapy in patients with MRD is currently unclear. 
Methods We conducted a prospective study to investigate the role of CAR-T therapy in patients with persistent/recurrent MRD-positive ALL in first remission. 
Results A total of 77 patients who had persistent/recurrent MRD were included. Of these patients, 43 were enrolled in the CAR-T group, 20 received chemotherapy as a bridge to allogeneic hematopoietic cell transplantation (allo-HSCT), and 14 patients received intensified chemotherapy. MRD negativity was achieved in 90.7% of the patients after CAR-T infusion. Patients who received CAR-T therapy had a higher 3-year leukemia-free survival (LFS) than patients who did not (77.8% vs. 51.1%, P = 0.033). Furthermore, patients in the CAR-T group had a higher 3-year LFS than those in the chemotherapy bridge-to-allo-HSCT group (77.8% [95% CI, 64.8–90.7%] vs. 68.7% [95% CI, 47.7–89.6%], P = 0.575) and had a significantly higher 3-year LFS than those in the intensified chemotherapy group (77.8% [95% CI, 64.8–90.7%] vs. 28.6% [95% CI, 4.9–52.3%], P = 0.001). Among the patients who received CAR-T therapy, eight were not bridged to allo-HSCT, and six (75%) remained in remission with a median follow-up of 23.0 months after CAR-T infusion. 
Conclusions Our findings show that CAR-T therapy can effectively eliminate MRD and improve survival in patients with a suboptimal MRD response.