1区 · 医学
ArticleOA
作者: Chen, Xiaojuan ; Zhou, Chunlin ; Wang, Jianxiang ; Xu, Yingxi ; Zou, Dehui ; Lv, Lulu ; Zhong, Mengjun ; Lv, Rui ; Liu, Fang ; Lu, Yang ; Zhu, Xiaofan ; Liu, Wei ; Liu, Kaiqi ; Wang, Huijun ; Liu, Bingcheng ; Wang, Min ; Wang, Ying ; Gong, Xiaoyuan ; Qiu, Lugui ; Wei, Hui ; Chen, Xia ; Gu, Runxia ; Guo, Ye ; Mi, Yingchang
Background:Recent evidence suggests that resistance to CD19 chimeric antigen receptor (CAR)-modified T cell therapy may be due to the presence of CD19 isoforms that lose binding to the single-chain variable fragment (scFv) in current use. As such, further investigation of CARs recognize different epitopes of CD19 antigen may be necessary.
Methods:We generated a new CD19 CAR T (HI19α-4-1BB-ζ CAR T, or CNCT19) that includes an scFv that interacts with an epitope of the human CD19 antigen that can be distinguished from that recognized by the current FMC63 clone. A pilot study was undertaken to assess the safety and feasibility of CNCT19-based therapy in both pediatric and adult patients with relapsed/refractory acute lymphoblastic leukemia (R/R B-ALL).
Results:Data from our study suggested that 90% of the 20 patients treated with infusions of CNCT19 cells reached complete remission or complete remission with incomplete count recovery (CR/CRi) within 28 days. The CR/CRi rate was 82% when we took into account the fully enrolled 22 patients in an intention-to-treat analysis. Of note, extramedullary leukemia disease of two relapsed patients disappeared completely after CNCT19 cell infusion. After a median follow-up of 10.09 months (range, 0.49–24.02 months), the median overall survival and relapse-free survival for the 20 patients treated with CNCT19 cells was 12.91 months (95% confidence interval [CI], 7.74–18.08 months) and 6.93 months (95% CI, 3.13–10.73 months), respectively. Differences with respect to immune profiles associated with a long-term response following CAR T cell therapy were also addressed. Our results revealed that a relatively low percentage of CD8+ naïve T cells was an independent factor associated with a shorter period of relapse-free survival (p = 0.012, 95% CI, 0.017–0.601).
Conclusions:The results presented in this study indicate that CNCT19 cells have potent anti-leukemic activities in patients with R/R B-ALL. Furthermore, our findings suggest that the percentage of CD8+ naïve T cells may be a useful biomarker to predict the long-term prognosis for patients undergoing CAR T cell therapy.
Trial registration:ClinicalTrials.gov: NCT02975687; registered 29 November, 2016. https://clinicaltrials.gov/ct2/keydates/NCT02975687