Genetically modified CD7-targeting allogeneic CAR-T cell therapy with enhanced efficacy for relapsed/refractory CD7-positive hematological malignancies: a phase I clinical study.

Chimeric antigen receptor (CAR)-T cell therapy against T cell malignancies faces major challenges including fratricide between CAR-T cells and product contamination from the blasts. Allogeneic CAR-T cells, generated from healthy donor T cells, can provide ready-to-use, blast-free therapeutic products, but their application could be complicated by graft-versus-host disease (GvHD) and host rejection. Here we developed healthy donor-derived, CD7-targeting CAR-T cells (RD13-01) with genetic modifications to resist fratricide, GvHD and allogeneic rejection, as well as to potentiate antitumor function. A phase I clinical trial (NCT04538599) was conducted with twelve patients recruited (eleven with T cell leukemia/lymphoma, and one with CD7-expressing acute myeloid leukemia). All patients achieved pre-set end points and eleven proceeded to efficacy evaluation. No dose-limiting toxicity, GvHD, immune effector cell-associated neurotoxicity or severe cytokine release syndrome (grade ≥ 3) were observed. 28 days post infusion, 81.8% of patients (9/11) showed objective responses and the complete response rate was 63.6% (7/11, including the patient with AML). 3 of the responding patients were bridged to allogeneic hematopoietic stem cell transplantation. With a median follow-up of 10.5 months, 4 patients remained in complete remission. Cytomegalovirus (CMV) and/or Epstein-Barr virus (EBV) reactivation was observed in several patients, and one died from EBV-associated diffuse large B-cell lymphoma (DLBCL). Expansion of CD7-negative normal T cells was detected post infusion. In summary, we present the first report of a Phase I clinical trial using healthy donor-derived CD7-targeting allogeneic CAR-T cells to treat CD7+ hematological malignancies. Our results demonstrated the encouraging safety and efficacy profiles of the RD13-01 allogeneic CAR-T cells for CD7+ tumors.

CRISPR/Cas9-Engineered Universal CD19/CD22 Dual-Targeted CAR-T Cell Therapy for Relapsed/Refractory B-cell Acute Lymphoblastic Leukemia.

PURPOSE: 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. PATIENTS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

[Mechanism of enhancement of the CTL activity in mice co-expressing CD80, CD86 and CD137L genes].

OBJECTIVE: To study the mechanism of enhancement of the CTL activity in mice co-expressing of CD80, CD86 and CD137L genes. METHODS: The mice were randomly divided into five groups, named A, B, C, D and E. The group A and B were control groups (CG). H22-BAL B/c HCC mouse model was established by subcutaneous injection with hepatocellular carcinoma cells of cell line H22-Wt (group A), H22-neo (group B), H22-CD80/CD86(+) (group C), H22-CD137L(+) (group D) and H22-CD80/CD86/CD137L(+) (group E), respectively. On the 14th, 35th, 56th and 84th day after the first inoculation of tumor cells, TUNEL staining and DNA ladder examination were used to detect apoptosis of splenic T lymphocytes in all groups at each post-inoculation time point. Electrophoretic mobility-shift assay (EMSA) method was used to detect the activity of nuclear factor kappaB (NF-kappaB) in splenic T lymphocytes in each group at each time point post-inoculation. RESULTS: Apoptosis was found in a great number of T lymphocytes in CG on the 14th day, much more than that in group C and E. The number of apoptotic T cells in group C had a significant difference compared with that in the group E from 14th to 84th day (P = 0.003). DNA ladder analysis showed typical positive results in group C and E. The significant apoptosis fragments were found in group C on 21st, 35th and 84th days. NF-kappaB activity of T cells in groups C and E was remarkably higher than that of groups CG and D, with higher in group D than that of CG (P = 0.002), and with no significant difference between group C and E on 14th day. The activity in group E was stable and remarkably higher than that of group C on 56th and 84th days after the first inoculation. CONCLUSION: H22-CD80/CD86/CD137L(+) induces higher NF-kappaB activity of the host T cells by synergistic action of CD28 and CD137, which may be one of the mechanisms of enhancement of the host CTL activity induced by co-expression of CD80, CD86 and CD137L genes.

Safety evaluation of donors for living-donor liver transplantation in Chinese mainland: a single-center report.

AIM: To discuss the safety of donors during living donor liver transplantation (LDLT) and the authors' experience with 50 cases. METHODS: Between January 1995 and March 2006, 50 patients with end-stage liver disease received LDLT in our department. Donors (at the age of 27-58 years) were healthy and antibody (ABO)-compatible. The protocol of evaluation and selection of donors, choice of surgical methods and strategy applied in the safety evaluation of donors were analyzed. RESULTS: A total of 115 candidate donors were evaluated for LDLT at our center. Of these, 50 underwent successful hepatectomy for living donation. The elimination rate for donors was 43.5%. Positive hepatitis serology and ABO incompatibility were the main factors for excluding candidates. All donors recovered uneventfully. The follow-up time ranged from 3 to 135 mo. The incidence of major and minor medical complications was 12.0% and 28.0%, respectively. CONCLUSION: LDLT provides an excellent approach to the problem of donor shortage in China. With a thorough and complete preoperative workup and meticulous intra- and postoperative management, LDLT can be performed with minimal donor morbidity.

Early experiences on living donor liver transplantation in China: multicenter report.

BACKGROUND: Because of the lack of brain death laws in China, the proportion of cadaveric organ donation is low. Many patients with end-stage liver disease die waiting for a suitable donor. Living donor liver transplantation (LDLT) would reduce the current discrepancy between the number of patients on the transplant waiting list and the number of available organ donors. We describe the early experience of LDLT in the mainland of China based on data from five liver transplant centers. METHODS: Between January 2001 and October 2003, 45 patients with end-stage liver disease received LDLT at five centers in China. The indication and timing, surgical techniques and complications, nonsurgical issues including rejection, infection, and advantages of LDLT in the series were reviewed. Actuarial patient and graft survival rates were calculated by using the Kaplan-Meier product-limit estimate. Statistical analysis was completed by using SPSS 10.0. RESULTS: All LDLT recipients were cirrhotic patients, except for one man with fulminant hepatic failure. Among the 45 cases of LDLT, 35 (77.8%) were performed in one center (the First Affiliated Hospital of Nanjing Medical University). The overall 1 and 3 year survival rate of the recipients was 93.1% and 92.0%, respectively. Of the 45 LDLT donors, there were 3 cases of biliary leakage, 2 subphrenic collections, 1 fat liquefaction around the incision and 1 biliary peritonitis after T tube removal. All donors recovered completely. CONCLUSIONS: LDLT provides an excellent approach to addressing the problem of donor shortage in China even though the operation is complicated, uncompromising and difficult with respect to the safety of the donors and receptors. Despite early technical hurdles having been overcome, perfection of technique is still necessarily. At present, LDLT is a good choice for the patients with irreversible liver disease.

[Surgical methods in living donor liver transplantation: with report of 50 cases].

OBJECTIVE: To investigate and evaluate different surgical methods applied in living-donor liver transplantation (LDLT). METHODS: Fifty patients with end-stage liver disease received LDLT in our department between January 1995 and March 2006. The data were analyzed on a retrospective basis. The choice of different surgical methods, strategies applied to ensure the safety of donors and indications of LDLT in the series were reviewed. RESULTS: All donors recovered uneventfully. Among the 50 patients, 47 recipients presented with end-stage cirrhosis, 3 patients suffered from malignant tumor. To date, 6 recipients died after LDLT, among them, 3 recipients died of the operation and the other 3 recipients died of long-term complications. Resected donor livers included 9 cases of segments V, VI, VII and VIII (not including the middle hepatic veins) and 1 case of segments V, VI, VII and VIII (including the middle hepatic veins), 36 cases of segments II, III and IV (including the middle hepatic veins) and 4 cases of segments II, III, and part of IV (not including middle hepatic veins). CONCLUSIONS: LDLT helps tackle the problem of donor shortage in the world. The process is complicated, and it is very important to choose appropriate surgical methods for the improvement of surgical achievement and donor safety.