Carcinoembryonic Antigen

The primary aim of this clinical trial was to determine the feasibility of delivering first-generation CAR T cell therapy to patients with advanced, CEACAM5+ malignancy. Secondary aims were to assess clinical efficacy, immune effector function and optimal dose of CAR T cells. Three cohorts of patients received increasing doses of CEACAM5+-specific CAR T cells after fludarabine pre-conditioning plus systemic IL2 support post T cell infusion. Patients in cohort 4 received increased intensity pre-conditioning (cyclophosphamide and fludarabine), systemic IL2 support and CAR T cells. No objective clinical responses were observed. CAR T cell engraftment in patients within cohort 4 was significantly higher. However, engraftment was short-lived with a rapid decline of systemic CAR T cells within 14 days. Patients in cohort 4 had transient, acute respiratory toxicity which, in combination with lack of prolonged CAR T cell persistence, resulted in the premature closure of the trial. Elevated levels of systemic IFNγ and IL-6 implied that the CEACAM5-specific T cells had undergone immune activation in vivo but only in patients receiving high-intensity pre-conditioning. Expression of CEACAM5 on lung epithelium may have resulted in this transient toxicity. Raised levels of serum cytokines including IL-6 in these patients implicate cytokine release as one of several potential factors exacerbating the observed respiratory toxicity. Whilst improved CAR designs and T cell production methods could improve the systemic persistence and activity, methods to control CAR T 'on-target, off-tissue' toxicity are required to enable a clinical impact of this approach in solid malignancies.

BackgroundThe diagnostic and prognostic significance of carcinoembryonic antigen (CEA), carbohydrate associated antigen 19-9 (CA19-9), alpha-fetoprotein (AFP) and cancer antigen 125 (CA125) in early gastric cancer have not been investigated yet. Thus, the present study aimed to explore the diagnostic and prognostic significance of the four tumor markers for early gastric cancer.MethodsFrom September 2008 to March 2015, 587 early gastric cancer patients were given radical gastrectomy in our center. The clinicopathological characteristics were recorded. The association between levels of CEA and CA19-9 and clinicopathological characteristics and prognosis of patients were analyzed.ResultsThere were 444 men (75.6%) and 143 women (24.4%). The median age was 57 years (ranged 21-85). The 1-, 3- and 5-year overall survival rate was 99.1%, 96.8% and 93.1%, respectively. The positive rate of CEA, CA19-9, AFP and CA125 was 4.3%, 4.8%, 1.5% and 1.9%, respectively. The positive rate of all markers combined was 10.4%. The associations between the clinicopathological features and levels of CEA and CA19-9 were analyzed. No significant association was found between CEA level and clinicopathological features. However, elevated CA19-9 level was correlated with female gender and presence of lymph node metastasis. Age > 60 years old, presence of lymph node metastasis and elevation of CEA level were independent risk factors for poor prognosis of early gastric cancer.ConclusionsThe positive rates of CEA, CA19-9, APF and CA125 were relatively low for early gastric cancer. Elevation of CA19-9 level was associated with female gender and presence of lymph node metastasis. Elevation of CEA level was an independent risk factor for the poor prognosis of early gastric cancer.

BackgroundThe therapeutic application of T cells endowing with chimeric antigen receptors (CARs) is faced with "on-target, off-tumor" toxicity against solid tumors, particularly in the treatment of the pancreatic cancer. To our best knowledge, the pancreatic cancer cell line AsPC-1 often highly expressed some distinct tumor-associated antigens, such as carcino-embryonic antigen (CEA) and mesothelin (MSLN). Therefore, in this research, we have characterized dual-receptor CAR-modified T cells (dCAR-T) that exert effective and safe cytotoxicity against AsPC-1 cells.MethodsBased on the dual signaling pathway of wild T cells, we designed a novel dCAR diagram specific for CEA and MSLN, which achieved comparable activity relative to that of conventional CAR-T cells (CEA-CAR T or MSLN-CAR T). In this dCAR, a tandem construct containing two physically separate structures, CEA-CD3ζ and MSLN-4/1BB signaling domains were effectively controlled with tumor antigens CEA and MSLN, respectively. Finally, the activity of dCAR-T cells has been verified via in vitro and in vivo experiments.ResultsIn the presence of cognate tumor cells (AsPC-1) expressing both CEA and MSLN, dCAR-T cells exerted high anti-tumor activity relative to that of other single-receptor CAR-T cells bearing only one signaling pathway (e.g., Cζ-CAR and MBB-CAR). In a xenograft model, dCAR-T cells significantly inhibited the growth of AsPC-1 cells yet no effect on the growth of non-cognate tumor cells. Furthermore, the released cytokines and T cell persistence in mice were comparable with that of conventional CAR-T cells, obtaining specific and controllable cytotoxicity.ConclusionsA novel type of CAR-T cells, termed dCAR-T, was designed with specific activities, that is, significant cytotoxicity for two antigen-positive tumor cells yet no cytotoxicity for single antigen-positive tumor cells. Dual-targeted CAR-T cells can be precisely localized at the tumor site and can exert high cytotoxicity against tumor cells, alleviating "on-target, off-tumor" toxicity and enabling accurate application of CAR-T cell therapy.

BackgroundThe clinical success of fluorescence-guided surgery is dependent on tumor-specific probes that can achieve high tumor-to-background contrast. Conventional near-infrared (NIR) fluorophores often alter the pharmacokinetic properties of the parental molecule that result in aggregation, altered biodistribution, and impaired tumor targeting.MethodsThis present study evaluates two charge-balanced heptamethine cyanine dyes, FNIR-Tag-766 and FNIR-Tag-804, conjugated to a humanized anti-carcinoembryonic antigen antibody (M5A). Their performance was compared to the standard M5A-IR800CW conjugate in both subcutaneous and orthotopic colorectal cancer xenograft models in mice. Mean fluorescence intensity (MFI), tumor-to-background ratio (TBR), and ex vivo biodistribution were compared.ResultsThe M5A-FNIR-766 conjugate produced a greater MFI in tumors at all timepoints compared to M5A-IR800CW, resulting in a significantly improved TBR. Ex vivo analysis at 96 h confirmed higher tumor accumulation for M5A-FNIR-766 and revealed a reduction in hepatic signal for both M5A-FNIR-Tag conjugates. The observations were concordant in the clinically relevant orthotopic model.ConclusionAntibody-fluorophore conjugates linked to the charge-modified FNIR-Tag dyes provide improved tumor-specific signals and a more favorable biodistribution profile than the same antibody conjugated to a conventional dye. By achieving superior performance through intrinsic fluorophore design rather than complex bioconjugation strategies, the approach provides a clinically translatable advancement for tumor-specific FGS.