Background: Despite the impressive complete remission (CR) induced by CD19 CART cell therapy in BALL , the high rate of complete responses is sometimes limited by the emergence of CD19-negative leukemia. Bispecific CAR-modified T cells targeting both CD19 and CD22 may overcome the limitation of CD19-negative relapse. Methods: We here report the design of a bispecific CAR simultaneous targeting of CD19 and CD22. We performed a phase 1 trial of bispecific CAR T cell therapy in patients with relapsed/refractory precursor BALL at a dose that ranged from 1.7 × 10 6 to 3 × 10 6 CAR T cells per kilogram of body weight. Results: We demonstrate bispecific CD19/CD22 CAR T cells could trigger robust cytolytic activity against target cells. MRD-negative CR was achieved in 6 out of 6 enrolled patients. Autologous CD19/CD22 CAR T cells proliferated in vivo and were detected in the blood, bone marrow, and cerebrospinal fluid. No neurotoxicity occurred in any of the 6 patients treated. Of note, one patient had a relapse with blast cells that no longer expressed CD19 and exhibited diminished CD22 site density approximately 5 months after treatment. Conclusion: In brief, autologous CD19/CD22 CAR T cell therapy is feasible and safe and mediates potent antileukemic activity in patients with relapsed/refractory BALL. Furthermore, the emergence of target antigen loss and expression downregulation highlights the critical need to anticipate antigen escape. Our study demonstrates the reliability of bispecific CD19/CD22 CAR T cell therapy in inducing remission in adult patients with relapsed/ refractory BALL. Trial registration: ClinicalTrials.gov identifier: NCT03185494.

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This study is an expanded and parallel clinical trial of EGFR-specific chimeric antigen receptor-engineered autologous T (CART) cell immunotherapy (NCT01869166) to assess the safety and activity of CART-EGFR cell therapy in EGFR-positive advanced unresectable, relapsed/metastatic biliary tract cancers (BTC). Patients with EGFR-positive (>50%) advanced unresectable, relapsed/metastatic BTCs were enrolled. Well-produced CART-EGFR cells were infused in a manner of dose escalation after the conditioning treatment with nab-paclitaxel (100-250 mg/m) and cyclophosphamide (15-35 mg/kg). A total of 19 patients (14 cholangiocarcinomas and 5 gallbladder carcinomas) received one to three cycles of CART-EGFR cell infusion (median CART cell dose, 2.65 × 10/kg; range, 0.8-4.1 × 10/kg) within 6 months. The CART-EGFR cell infusion was tolerated, but 3 patients suffered grade ≥3 acute fever/chill. Grade 1/2 target-mediated toxicities including mucosal/cutaneous toxicities and acute pulmonary edema and grade ≥3 lymphopenia and thrombocytopenia related to the conditioning treatment were observed. Of 17 evaluable patients, 1 achieved complete response and 10 achieved stable disease. The median progression-free survival was 4 months (range, 2.5-22 months) from the first cycle of treatment. Analysis of data indicated that the enrichment of central memory T cells (Tcm) in the infused CART-EGFR cells improved the clinical outcome. The CART-EGFR cell immunotherapy was a safe and active strategy for EGFR-positive advanced BTCs. The enrichment of Tcm in the infused CART-EGFR cells could predict clinical response. .

Low-dose DNA-demethylating agent decitabine therapy is effective in a subgroup of cancer patients. It remains largely elusive for the biomarker to predict therapeutic response and the underlying antitumor mechanisms, especially the impact on host antitumor immunity. The influence of low-dose decitabine on T cells was detected both and Moreover, a test cohort and a validation cohort of advanced solid tumor patients with low-dose decitabine-based treatment were involved. The activation, proliferation, polarization, and cytolysis capacity of CD3 T cells were analyzed by FACS and CCK8 assay. Kaplan-Meier and Cox proportional hazard regression analysis were performed to investigate the prognostic value of enhanced T-cell activity following decitabine epigenetic therapy. Low-dose decitabine therapy enhanced the activation and proliferation of human IFNγ T cells, promoted Th1 polarization and activity of cytotoxic T cells both and, which in turn inhibited cancer progression and augmented the clinical effects of patients. In clinical trials, increased IFNγ T cells and increased T-cell cytotoxicity predicted improved therapeutic responses and survival in the test cohort and validation cohort. We find that low-dose decitabine therapy promotes antitumor T-cell responses by promoting T-cell proliferation and the increased IFNγ T cells may act as a potential prognostic biomarker for the response to decitabine-based antitumor therapy..

Background Chimeric antigen receptor T (CAR-T) cell therapy simultaneously against CD19 and CD22 is an attractive strategy to address the antigen escape relapse after CD19-directed CAR-T cell therapies. However, the potential of optimizing the durability of remission by this approach in patients with B cell acute lymphoblastic leukemia (B-ALL) remains a critical unanswered question so far. Case presentation We treated an adult patient with relapsed and refractory B-ALL after haploidentical hematopoietic stem cell transplantation (HSCT) by administering haploidentical CAR-T cells targeting both CD19 and CD22 following preparative lymphodepleting chemotherapy. This patient has remained in minimal residual disease-negative remission for more than 14 months and has been tapered off graft versus host disease prophylaxis. Conclusions CAR simultaneously targeting CD19 and CD22 has the potential of inducing long-term remission in patients with B-ALL. Electronic supplementary material The online version of this article (10.1186/s13045-019-0741-6) contains supplementary material, which is available to authorized users.