CAR T cells with dual targeting of CD19 and CD22 in pediatric and young adult patients with relapsed or refractory B cell acute lymphoblastic leukemia: a phase 1 trial.
Chimeric antigen receptor (CAR) T cells targeting CD19 or CD22 have shown remarkable activity in B cell acute lymphoblastic leukemia (B-ALL). The major cause of treatment failure is antigen downregulation or loss. Dual antigen targeting could potentially prevent this, but the clinical safety and efficacy of CAR T cells targeting both CD19 and CD22 remain unclear. We conducted a phase 1 trial in pediatric and young adult patients with relapsed or refractory B-ALL (n = 15) to test AUTO3, autologous transduced T cells expressing both anti-CD19 and anti-CD22 CARs (AMELIA trial, EUDRA CT 2016-004680-39). The primary endpoints were the incidence of grade 3-5 toxicity in the dose-limiting toxicity period and the frequency of dose-limiting toxicities. Secondary endpoints included the rate of morphological remission (complete response or complete response with incomplete bone marrow recovery) with minimal residual disease-negative response, as well as the frequency and severity of adverse events, expansion and persistence of AUTO3, duration of B cell aplasia, and overall and event-free survival. The study endpoints were met. AUTO3 showed a favorable safety profile, with no dose-limiting toxicities or cases of AUTO3-related severe cytokine release syndrome or neurotoxicity reported. At 1 month after treatment the remission rate (that is, complete response or complete response with incomplete bone marrow recovery) was 86% (13 of 15 patients). The 1 year overall and event-free survival rates were 60% and 32%, respectively. Relapses were probably due to limited long-term AUTO3 persistence. Strategies to improve CAR T cell persistence are needed to fully realize the potential of dual targeting CAR T cell therapy in B-ALL.
Cordoba S
,Onuoha S
,Thomas S
,Pignataro DS
,Hough R
,Ghorashian S
,Vora A
,Bonney D
,Veys P
,Rao K
,Lucchini G
,Chiesa R
,Chu J
,Clark L
,Fung MM
,Smith K
,Peticone C
,Al-Hajj M
,Baldan V
,Ferrari M
,Srivastava S
,Jha R
,Arce Vargas F
,Duffy K
,Day W
,Virgo P
,Wheeler L
,Hancock J
,Farzaneh F
,Domning S
,Zhang Y
,Khokhar NZ
,Peddareddigari VGR
,Wynn R
,Pule M
,Amrolia PJ
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Sequential CD19 and CD22 chimeric antigen receptor T-cell therapy for childhood refractory or relapsed B-cell acute lymphocytic leukaemia: a single-arm, phase 2 study.
Relapses frequently occur following CD19-directed chimeric antigen receptor (CAR) T-cell treatment for relapsed or refractory B-cell acute lymphocytic leukaemia in children. We aimed to assess the activity and safety of sequential CD19-directed and CD22-directed CAR T-cell treatments.
This single-centre, single-arm, phase 2 trial, done at Beijing GoBroad Boren Hospital, Beijing, China, included patients aged 1-18 years who had relapsed or refractory B-cell acute lymphocytic leukaemia with CD19 and CD22 positivity greater than 95% and an Eastern Cooperative Oncology Group performance status of 0-2. Patients were initially infused with CD19-directed CAR T cells intravenously, followed by CD22-directed CAR T-cell infusion after minimal residual disease-negative complete remission (or complete remission with incomplete haematological recovery) was reached and all adverse events (except haematological adverse events) were grade 2 or better. The target dose for each infusion was 0·5 × 106 to 5·0 × 106 cells per kg. The primary endpoint was objective response rate at 3 months after the first infusion. Secondary endpoints were duration of remission, event-free survival, disease-free survival, overall survival, safety, pharmacokinetics, and B-cell quantification. The prespecified activity analysis included patients who received the target dose and the safety analysis included all treated patients. This study is registered with ClinicalTrials.gov, NCT04340154, and enrolment has ended.
Between May 28, 2020, and Aug 16, 2022, 81 participants were enrolled, of whom 31 (38%) were female and 50 (62%) were male. Median age was 8 years (IQR 6-10), all patients were Asian. All 81 patients received the first infusion and 79 (98%) patients received sequential infusions, CD19-directed CAR T cells at a median dose of 2·7 × 106 per kg (IQR 1·1 × 106 to 3·7 × 106) and CD22-directed CAR T cells at a median dose of 2·2 × 106 per kg (1·1 × 106 to 3·7 × 106), with a median interval of 39 days (37-41) between the two infusions. 62 (77%) patients received the target dose, including two patients who did not receive CD22 CAR T cells. At 3 months, 60 (97%, 95% CI 89-100) of the 62 patients who received the target dose had an objective response. Median follow-up was 17·7 months (IQR 11·4-20·9). 18-month event-free survival for patients who received the target dose was 79% (95% CI 66-91), duration of remission was 80% (68-92), and disease-free survival was 80% (68-92) with transplantation censoring; overall survival was 96% (91-100). Common adverse events of grade 3 or 4 between CD19-directed CAR T-cell infusion and 30 days after CD22-directed CAR T-cell infusion included cytopenias (64 [79%] of 81 patients), cytokine release syndrome (15 [19%]), neurotoxicity (four [5%]), and infections (five [6%]). Non-haematological adverse events of grade 3 or worse more than 30 days after CD22-directed CAR T-cell infusion occurred in six (8%) of 79 patients. No treatment-related deaths occurred. CAR T-cell expansion was observed in all patients, with a median peak at 9 days (IQR 7-14) after CD19-directed and 12 days (10-15) after CD22-directed CAR T-cell infusion. At data cutoff, 35 (45%) of 77 evaluable patients had CAR transgenes and 59 (77%) had B-cell aplasia.
This sequential strategy induced deep and sustained responses with an acceptable toxicity profile, and thus potentially provides long-term benefits for children with this condition.
The National Key Research & Development Program of China, the CAMS Innovation Fund for Medical Sciences (CIFMS), and the Non-Profit Central Research Institute Fund of Chinese Academy of Medical Sciences.
For the Chinese translation of the abstract see Supplementary Materials section.
Pan J
,Tang K
,Luo Y
,Seery S
,Tan Y
,Deng B
,Liu F
,Xu X
,Ling Z
,Song W
,Xu J
,Duan J
,Wang Z
,Li C
,Wang K
,Zhang Y
,Yu X
,Zheng Q
,Zhao L
,Zhang J
,Chang AH
,Feng X
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CRISPR/Cas9-Engineered Universal CD19/CD22 Dual-Targeted CAR-T Cell Therapy for Relapsed/Refractory B-cell Acute Lymphoblastic Leukemia.
Autologous chimeric antigen receptor T (CAR-T) cell therapy is an effective treatment for relapsed/refractory acute lymphoblastic leukemia (r/r ALL). However, certain characteristics of autologous CAR-T cells can delay treatment availability. Relapse caused by antigen escape after single-targeted CAR-T therapy is another issue. Therefore, we aim to develop CRISPR-edited universal off-the-shelf CD19/CD22 dual-targeted CAR-T cells as a novel therapy for r/r ALL.
In this open-label dose-escalation phase I study, universal CD19/CD22-targeting CAR-T cells (CTA101) with a CRISPR/Cas9-disrupted TRAC region and CD52 gene to avoid host immune-mediated rejection were infused in patients with r/r ALL. Safety, efficacy, and CTA101 cellular kinetics were evaluated.
CRISPR/Cas9 technology mediated highly efficient, high-fidelity gene editing and production of universal CAR-T cells. No gene editing-associated genotoxicity or chromosomal translocation was observed. Six patients received CTA101 infusions at doses of 1 (3 patients) and 3 (3 patients) × 106 CAR+ T cells/kg body weight. Cytokine release syndrome occurred in all patients. No dose-limiting toxicity, GvHD, neurotoxicity, or genome editing-associated adverse events have occurred to date. The complete remission (CR) rate was 83.3% on day 28 after CTA101 infusion. With a median follow-up of 4.3 months, 3 of the 5 patients who achieved CR or CR with incomplete hematologic recovery (CR/CRi) remained minimal residual disease (MRD) negative.
CRISPR/Cas9-engineered universal CD19/CD22 CAR-T cells exhibited a manageable safety profile and prominent antileukemia activity. Universal dual-targeted CAR-T cell therapy may offer an alternative therapy for patients with r/r ALL.
Hu Y
,Zhou Y
,Zhang M
,Ge W
,Li Y
,Yang L
,Wei G
,Han L
,Wang H
,Yu S
,Chen Y
,Wang Y
,He X
,Zhang X
,Gao M
,Yang J
,Li X
,Ren J
,Huang H
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Combination of CD19 and CD22 CAR-T cell therapy in relapsed B-cell acute lymphoblastic leukemia after allogeneic transplantation.
The prognosis of relapsed acute lymphoblastic leukemia (ALL) after allogeneic transplantation is dismal when treated with conventional approaches. While single-target CD19 or CD22 chimeric antigen receptor (CAR) T-cell therapy has achieved high complete remission (CR) rates in refractory/relapsed B-ALL, it could not maintain a durable remission in most patients. To prolong relapse-free survival, we sequentially combined CD19 and CD22 CAR-T cells to treat post-transplant relapsed B-ALL patients with both CD19/CD22 antigen expression on lymphoblasts. Patient-derived donor cells were collected to produce CAR-T cells that were transfected by lentiviral vectors encoding second generation CARs composed of CD3ζ and 4-1BB. The second T-cell infusion was scheduled at least 1 month, and usually within 6 months after the first CAR-T treatment. Twenty-seven adult and pediatric patients, including 11 (41%) with extramedullary diseases (EMD), received the first CD19 CAR-T and 23 (85%) achieved CR. Subsequently, 21 out of 27 patients received the second CD22 CAR-T and were followed-up for a median of 19.7 (range, 5.6-27.3) months; 14 cases remained in CR, seven relapsed and two of them died from disease progression; Kaplan-Meier survival analysis showed overall survival and event-free survival rates of 88.5% and 67.5%, respectively, at both 12 months and 18 months. CAR-T associated graft-versus-host disease (GVHD) occurred in 23% of patients, with 8% new-onset acute GVHD and 15% persistent or worsened pre-existing cGVHD before CAR-T. This combination strategy of sequential CD19 and CD22 CAR-T therapy significantly improved the long-term survival in B-ALL patients who relapsed after transplantation.
Liu S
,Deng B
,Yin Z
,Lin Y
,An L
,Liu D
,Pan J
,Yu X
,Chen B
,Wu T
,Chang AH
,Tong C
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