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case_images: (A) Timeline of multi-line therapies before claudin18.2-targeted CAR-T therapy, including pancreaticoduodenectomy and adjuvant chemotherapies, as well as multiple metastases. (B) Postoperative pathology revealed pancreatic ductal adenocarcinoma. On the left is hematoxylin and eosin (H&E) staining of tumor tissues (original magnification 100x), in the middle is immunohistochemical (IHC) staining for claudin 18.2 (original magnification 100x) and on the right is IHC staining for claudin 18.2 (original magnification 400x).
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case_images: The postoperative pathology indicated pancreatic ductal adenocarcinoma (pT2N2M0, stage III) ( Figure 1B ). Given tumor recurrence and metastasis after multi-line therapies ( Figure 1A ), the patient and his family strongly requested participation in clinical trials of CAR-T cell therapy. Therefore, immunochemistry was performed to detect claudin18.2 expression in tumor tissues, which showed high levels of claudin18.2 expression (positive tumor cell rate >=70%) ( Figure 1B ).
case_images: (A) Timeline of patient preparation and CAR-T cell therapy from leukapheresis to 1 month after claudin18.2-targeted CAR-T cell infusion. (B) Changes in body temperature and the levels of CRP at different time points after CAR-T cell infusion. (C) The levels of IL-6, IL-8, and IFN-gamma in serum at different time points after CAR-T cell infusion. (D) The structure of claudin18.2-targeted CAR. (E) The percentage of claudin18.2-targeted CAR-T cells in peripheral blood at different time points. The plot was gated on peripheral blood lymphocytes. (F) The percentage of CD4+ CAR-T cells in peripheral blood at different time points. The plot was gated on peripheral blood lymphocytes. (G) The percentage of CD8+ CAR-T cells in peripheral blood at different time points. The plot was gated on peripheral blood lymphocytes. (H) The percentage of central memory CD4+ T cells in peripheral blood. The plot was gated on peripheral blood CD4+ lymphocytes. (I) The percentage of central memory CD8+ T cells in peripheral blood. The plot was gated on peripheral blood CD8+ lymphocytes.
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case_images: T cells were collected from the patient's peripheral blood on September 30, 2022, and then genetically engineered to express a chimeric antigen receptor (CAR) which contains a humanized anti-claudin18.2 single-chain variable fragment (scFv) ( Figure 2D ). Then, the patient received lymphodepleting chemotherapy with FC regimen (fludarabine 50 mg/m2 day -5 to day -3, cyclophosphamide 400 mg/m2 day -5 to day -3) on November 16, 2022. Given the advanced age and poor tolerability of the patient, the patient was treated with a single infusion of claudin 18.2-targeted CAR-T cells at a dose of 1. 2 x 106 cells/kg on November 21, 2022 ( Figure 2A ). The patient experienced fever 3 days after CAR-T cell infusion ( Figure 2B ), accompanied by fatigue, episodic upper abdominal pain, and nausea. The levels of serum IL-6 was significantly elevated and reached 389.6 pg/mL on day 6 ( Figure 2C ), which suggested grade 2 CRS. CAR-T cell expansion reached peak levels of 3.75% with 19/muL in peripheral blood on day 14 ( Figure 2E ), and the expansion of CD4 CAR-T cells and CD8 CAR-T cells both reached peak blood levels on day 14 ( Figures 2F, G ). CD4+ T cells was markedly increased 1 month after claudin 18.2-targeted CAR-T cell therapy ( Figure 2H ), but the proportion of central memory CD8+ T cells reached peak levels on day 17 and then experienced a decline ( Figure 2I ). CA19-9 maintained normal levels 5 months after CAR-T cell therapy ( Figure 3D ), and PET-CT scan revealed no recurrence of neck and lung lesions 8 months after CAR-T cell therapy ( Figures 3A, B ).
case_images: (A) PET/CT showed the disappearance of cervical lymph node metastasis 1 month after claudin18.2-targeted CAR-T cell therapy, and it remained in remission 8 months after CAR-T cell infusion. (B) PET/CT showed the disappearance of lung metastasis 1 month after claudin18.2-targeted CAR-T cell therapy, and it remained in remission 8 months after CAR-T cell infusion. (C) PET/CT showed tumor recurrence at the surgical resection site 8 months after CAR-T cell infusion (D) The levels of CA19-9 were markedly decreased after CAR-T cell infusion.
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case_images: Surprisingly, the levels of the tumor marker CA19-9 were significantly decreased from 1100 U/mL to 25.85U/mL and reached normal range 1 month after CAR-T cell infusion ( Figure 3D ), and PET-CT showed the complete disappearance of tumor lesions, including cervical lymph node metastasis and lung metastasis ( Figures 3A, B ). CD4+ T cells was markedly increased 1 month after claudin 18.2-targeted CAR-T cell therapy ( Figure 2H ), but the proportion of central memory CD8+ T cells reached peak levels on day 17 and then experienced a decline ( Figure 2I ). CA19-9 maintained normal levels 5 months after CAR-T cell therapy ( Figure 3D ), and PET-CT scan revealed no recurrence of neck and lung lesions 8 months after CAR-T cell therapy ( Figures 3A, B ). Unfortunately, PET-CT showed tumor recurrence in situ 8 months after CAR-T cell infusion ( Figure 3C ), and biopsy of tumor tissues showed claudin 18.2-negative ( Figure 4B ).
case_images: (A) Gastroscopy revealed gastric mucosal injury 2 and 4 months after claudin18.2-targeted CAR-T cell therapy, including diffuse gastric mucosal edema and gastric mucosal denudation. The mucosal injury of gastric and duodenal anastomoses as well as gastric mucosal edema was significantly alleviated 8 months after CAR-T cell infusion. (B) Biopsy of tumor tissues showed claudin18.2-negative relapse 8 months after claudin18.2-targeted CAR-T cell therapy. On the left is H&E staining of tumor tissues 8 months after CAR-T cell therapy (original magnification 100x), in the middle is IHC staining for claudin 18.2 8 months after CAR-T cell therapy (original magnification 100x) and on the right is IHC staining for claudin 18.2 8 months after CAR-T cell therapy (original magnification 400x).
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case_images: Unfortunately, PET-CT showed tumor recurrence in situ 8 months after CAR-T cell infusion ( Figure 3C ), and biopsy of tumor tissues showed claudin 18.2-negative ( Figure 4B ). Of note, the gastroscopy and biopsy revealed diffuse gastric mucosal edema, hyperemia, and denudation, accompanied by a large number of lymphocyte infiltration 2 and 4 months after claudin18.2-targeted CAR-T cell therapy ( Figure 4A ), which were partially alleviated by proton pump inhibitors, prokinetic drugs, and gastric mucosal protectants. In addition, a nasogastric tube was used for nutritional support, and the patient returned to free feeding now ( Figure 4A ).