Chimeric antigen receptor-modified T cells for the immunotherapy of patients with EGFR-expressing advanced relapsed/refractory non-small cell lung cancer

The successes achieved by chimeric antigen receptor-modified T(CAR-T) cells in hematological malignancies raised the possibility of their use in non-small lung cancer(NSCLC). In this phase I clinical study(NCT01869166), patients with epidermal growth factor receptor(EGFR)-positive(>50% expression), relapsed/refractory NSCLC received escalating doses of EGFR-targeted CAR-T cell infusions. The EGFR-targeted CAR-T cells were generated from peripheral blood after a 10 to 13-day in vitro expansion. Serum cytokines in peripheral blood and copy numbers of CAR-EGFR transgene in peripheral blood and in tissue biopsy were monitored periodically. Clinical responses were evaluated with RECIST1.1 and immune-related response criteria, and adverse events were graded with CTCAE 4.0. The EGFR-targeted CAR-T cell infusions were well-tolerated without severe toxicity. Of 11 evaluable patients, two patients obtained partial response and five had stable disease for two to eight months. The median dose of transfused CAR+ T cells was 0.97×10~7 cells kg^(-1)(interquartile range(IQR), 0.45 to 1.09×10~7 cells kg^(-1)). Pathological eradication of EGFR positive tumor cells after EGFR-targeted CAR-T cell treatment can be observed in tumor biopsies, along with the CAR-EGFR gene detected in tumor-infiltrating T cells in all four biopsied patients. The EGFR-targeted CAR-T cell therapy is safe and feasible for EGFR-positive advanced relapsed/refractory NSCLC.

Phase I study of chimeric antigen receptor modified T cells in treating HER2-positive advanced biliary tract cancers and pancreatic cancers

This phase I clinical trial （NCT01935843） is to evaluate the safety, feasibility, and activity of chimeric antigen receptor-engineered T cell （CART） immunotherapy tar- geting human epidermal growth factor receptor 2 （HER2） in patients with advanced biliary tract cancers （BTCs） and pancreatic cancers （PCs）. Eligible patients with HER2-positive （〉50%） BTCs and PCs were enrolled in the trial. Well cultured CART-HER2 cells were infused following the conditioning treatment composed of nab- paclitaxel （100-200 mg/m2） and cyclophosphamide （15-35 mglkg）. CAR transgene copy number in the peripheral blood was serially measured to monitor the expansion and persistence of CART-HER2 cells in vivo. Eleven enrolled patients received 1 to 2-cycle CART- HER2 cell infusion （median CAR＋ T cell 2.1× 10^6/kg）. The conditioning treatment resulted in mild-to-moderate fatigue, nausea/vomiting, myalgialarthralgia, and lym- phopenia. Except one grade-3 acute febrile syndrome and one abnormal elevation of transaminase （〉9 ULN）, adverse events related to the infusion of CART-HER2 cells were mild-to-moderate. Post-infusion toxicities included one case of reversible severe upper gastroin- testinal hemorrhage which occurred in a patient with gastric antrum invaded by metastasis 11 days after the CART-HER2 cell infusion, and 2 cases of grade 1-2delayed fever, accompanied by the release of C-reactive protein and interleukin-6. All patients were evaluable for assessment of clinical response, among which 1 obtained a 4.5-months partial response and 5 achieved stable disease. The median progression free survival was 4.8 months （range, 1.5-8.3 months）. Finally, data from this study demonstrated the safety and feasibility of CART-HER2 immunotherapy, and showed encourag- ing signals of clinical activity.

Effective and persistent antitumor activity of HER2-directed CAR-T cells against gastric cancer cells in vitro and xenotransplanted tumors in vivo

Human epidermal growth factor receptor 2 （HER2） pro- teins are overexpressed in a high proportion of gastric cancer （GC） cases and affect the maintenance of cancer stem cell （CSC） subpopulations, which are used as tar- gets for the clinical treatment of patients with HER2- positive GC. Despite improvements in survival, numer- ous HER2-positive patients fail treatment with trastuzu- mab, highlighting the need for more effective therapies. In this study, we generated a novel type of genetically modified human T cells, expressing a chimeric antigen receptor （CAR）, and targeting the GC cell antigen HER2, which harbors the CD137 and CD3/; moieties. Our findings show that the expanded CART cells, expressing an increased central memory phenotype, were activated by the specific recognition of HER2 antigens in an MHC-in- dependent manner, and effectively killed patient-derived HER2-positive GC cells. In HER2-positive xenograft tumors, CART cells exhibited considerably enhanced tumor inhibition ability, long-term survival, and homing totargets, compared with those of non-transduced T cells. The sphere-forming ability and in vivo tumorigenicity of patient-derived gastric cancer stem-like cells, expressing HER2 and the CD44 protein, were also inhibited. Our results support the future development and clinical application of this adoptive immunotherapy in patients with HER2-positive advanced GC.

An analytical biomarker for treatment of patients with recurrent B-ALL after remission induced by infusion of anti-CD19 chimeric antigen receptor T(CAR-T) cells

Anti-CD19 chimeric antigen receptor-modified T(CAR-T-19) cells have emerged as a powerful targeted immunotherapy for B-cell lineage acute lymphoblastic leukemia with a remarkable clinical response in recent trials. Nonetheless, few data are available on the subsequent clinical monitoring and treatment of the patients, especially those with disease recurrence after CAR-T-19 cell infusion. Here, we analyzed three patients who survived after our phase I clinical trial and who were studied by means of biomarkers reflecting persistence of CAR-T-19 cells in vivo and predictive factors directing further treatment. One patient achieved 9-week sustained complete remission and subsequently received an allogeneic hematopoietic stem cell transplant. Another patient who showed relapse after 20 weeks without detectable leukemia in the cerebrospinal fluid after CAR-T-19 cell treatment was able to achieve a morphological remission under the influence of stand-alone low-dose chemotherapeutic agents. The third patient gradually developed extensive extramedullary involvement in tissues with scarce immune-cell infiltration during a long period of hematopoietic remission after CAR-T-19 cell therapy. Long-term and discontinuous increases in serum cytokines(mainly interleukin 6 and C-reactive protein) were identified in two patients(Nos. 1 and 6) even though only a low copy number of CAR molecules could be detected in their peripheral blood. This finding was suggestive of persistent functional activity of CAR-T-19 cells. Combined analyses of laboratory biomarkers with their clinical manifestations before and after salvage treatment showed that the persistent immunosurveillance mediated by CAR-T-19 cells would inevitably potentiate the leukemia-killing effectiveness of subsequent chemotherapy in patients who showed relapse after CAR-T-19-induced remission.

Optimal model establishment of whole-process management data for CAR-T therapy in China—how should this be done?

Chimeric antigen receptor(CAR)T-cell therapy utilizes patients’own T lymphocytes that are engineered to attack cancer cells[1,2,3].With the US Food and Drug Administration(FDA)approval of four CD19-and one BCMA-targeted CAR therapy for B cell malignancies[4,5],CAR T-cell therapy has finally reached the status of a medicinal product.

Exploring innate immunity in cancer immunotherapy: opportunities and challenges

The recognition of the important role of cancer immunity in tumors has led to the introduction of immunotherapeutic strategies. Most of the immunomodulatory approaches currently being developed engage the adaptive immune system. The clinical approval of checkpoint inhibitors and chimeric antigen receptor (CAR) T-cell therapy has led to considerable success in treating hematologic malignancies.1,2,3,4 However, for the majority of patients with solid tumors, little or no progress has been seen. The efficacy of immunotherapies is limited by the complexities of a diverse set of immune cells and interactions between tumor cells and all other cells in the local microenvironment of solid tumors. A large proportion of immune cells in and around solid tumors derive from the innate arm of the immune system, and using these innate cells against tumors offers an alternative immunotherapeutic option, while current strategies mainly focus on the adaptive arm of the immune system.5 In a recent issue of Cell research, Lv et al.6 discovered that Mn2+ played a critical role in the innate immune sensing of tumors, as Mn-insufficient mice poorly controlled tumor growth and metastasis. Mechanistically, Mn2+ promoted dendritic cell (DC) and macrophage maturation and tumor-specific antigen presentation, augmented CD8+ T-cell differentiation and activation and NK cell activation, and increased memory CD8+ T cells in a cyclic-AMP synthase (cGAS)-stimulator of interferon genes (STING)-dependent manner, uncovering a critical role of Mn in bridging innate and adaptive immunity for tumor surveillance.