PMC8186315_01
Patient treatment history and response to piggyBac-generated CAR19-T cells. (A) Patient's disease progression and lymphoma treatment history. (B) Pre-treatment PET-CT, showing extensive invasion of tumors in gastric wall (SUVmax 13.2-18.0), small intestines (SUVmax 6.7) and bone marrow (SUVmax 2.6-3.2), scoring 5 points per Deauville criteria. (C) Pre-treatment abdominal CT, showing an abnormal mass sized as 3.0 x 2.2 cm (arrow). (D) PET-CT in the 1st month post-infusion, showing diminished invasion of tumors in small intestines (SUVmax 4.6) scoring 3 points per Deauville criteria. (E) Abdominal CT scans in the 1st month, showing an abnormal mass sized as 1.6 x 1.0 cm (arrow). (F) PET-CT scans were consistent with a complete metabolic response in the 2nd month post-infusion. (G) Normal Abdominal CT in the 2nd month.
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A 53-year-old Chinese male patient was diagnosed as follicular lymphoma (grade 3A, stage II, group B) in May 2017 and achieved first CR after two cycles of R-CHOP ( Figure 1 ). Positron emission tomography (PET)-CT scans suggested extensive invasion of lymphoma in gastric wall, small intestines and bone marrow, scoring 5 points per Deauville criteria ( Figure 1 ). Abdominal CT scans showed an abnormal mass sized as 3.0 x 2.2 cm ( Figure 1 ). The patient obtained a partial remission (PR) in the 1st month per Lugano criteria ( Figure 1D ). In the 2nd month, PET-CT scans were consistent with a complete metabolic response, and abdominal CT scans were normal ( Figure 1F ).
CD19CAR structure and immunophenotype of infused piggyBac-generated CAR19-T cell products. (A) Schematic diagram of CD19CAR. SP, CDS signal peptide; TM, Transmembrane; PA, SV40 Poly A signal. (B) In the final infused products, the CAR transfection efficiency was 42.97%, including 33.28% of CD4+CAR+ cells and 13.54% of stem-cell memory T cells (CD45RO+CCR7+CD62L+).
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The CD19CAR incorporated an FMC63 mAb-derived single chain variable fragment, a human CD8alpha hinge and transmembrane domain, an intracellular 4-1BB (CD137) costimulatory domain, and a cytoplasmic CD3zeta signal ( Figure 2 ). In the final infused cell products, the CAR transfection efficiency was 42.97%, including 33.28% of CD4+CAR+ cells and 13.54% of SCM T cells ( Figure 2 ).
Clinical monitoring after infusion of piggyBac-generated CAR19-T cells. (A) Trends of Interleukin(IL)-2, IL-4, IL-6, IL-10, tumor necrosis factor alpha (TNFalpha) and interferon (INF) during 28 days after infusion. (B) Trend of C-reactive protein (CRP) was associated with temperature (T) rising during 28 days after infusion. (C) CAR19 copies in peripheral blood were measured by quantitative polymerase chain reaction. (D, E) The peak values of ferritin and lactate dehydrogenase (LHD) after infusion were later than temperature. (F) Changes of white blood cells (WBC), neutrophils (NEC), platelet (PLT) and hemoglobin (Hb) during 28 days after infusion.
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As the body temperature rose after infusion, serum IL-6 and C-reactive protein significantly elevated, peaked at 598.5 and 73.8 mg/l, respectively (36-fold and 9-fold over upper limit of normal) ( Figure 3A ). The CAR copies increased dramatically and peaked at 103,000 copies/ug on day 14 ( Figure 3 ). The peak of ferritin and lactate dehydrogenase were detected on day 24, later than the time when toxicity culminated ( Figure 3D ). Moreover, he developed grade 3-4 hematological toxicities, which were relieved during the 1st month ( Figure 3 ). The CAR copies could be detected in peripheral blood until the 9th month post-infusion by quantitative polymerase chain reaction ( Figure 3 ).