Purpose T cells can be genetically modified to express an anti-CD19 chimeric antigen receptor (CAR). We assessed the safety and efficacy of administering autologous anti-CD19 CAR T cells to patients with advanced CD19+ B-cell malignancies. Patients and Methods We treated 15 patients with advanced B-cell malignancies. Nine patients had diffuse large B-cell lymphoma (DLBCL), two had indolent lymphomas, and four had chronic lymphocytic leukemia. Patients received a conditioning chemotherapy regimen of cyclophosphamide and fludarabine followed by a single infusion of anti-CD19 CAR T cells. Results Of 15 patients, eight achieved complete remissions (CRs), four achieved partial remissions, one had stable lymphoma, and two were not evaluable for response. CRs were obtained by four of seven evaluable patients with chemotherapy-refractory DLBCL; three of these four CRs are ongoing, with durations ranging from 9 to 22 months. Acute toxicities including fever, hypotension, delirium, and other neurologic toxicities occurred in some patients after infusion of anti-CD19 CAR T cells; these toxicities resolved within 3 weeks after cell infusion. One patient died suddenly as a result of an unknown cause 16 days after cell infusion. CAR T cells were detected in the blood of patients at peak levels, ranging from nine to 777 CAR-positive T cells/μL. Conclusion This is the first report to our knowledge of successful treatment of DLBCL with anti-CD19 CAR T cells. These results demonstrate the feasibility and effectiveness of treating chemotherapy-refractory B-cell malignancies with anti-CD19 CAR T cells. The numerous remissions obtained provide strong support for further development of this approach.

The identification of many tumor-associated epitopes as nonmutated “self” Ags led to the hypothesis that the induction of large numbers of self/tumor Ag-specific T cells would be prevented because of central and peripheral tolerance. We report in this study on vaccination efforts in 95 HLA-A*0201 patients at high risk for recurrence of malignant melanoma who received prolonged immunization with the “anchor-modified” synthetic peptide, gp100209–217(210M). Vaccination using this altered peptide immunogen was highly effective at inducing large numbers of self/tumor-Ag reactive T cells in virtually every patient tested, with levels as high as 42% of all CD8+ T cells assessed by tetramer analysis. From 1 to 10% of all CD8+ cells were tumor-Ag reactive in 44% of patients and levels >10% were generated in 17% of patients. These studies were substantiated using the ELISPOT assay and a bulk cytokine release assay. Although our data regarding “tumor escape” were inconclusive, some patients had growing tumors that expressed Ag and HLA-A*0201 in the presence of high levels of antitumor T cells. There was no difference in the levels of antitumor Ag-specific T cells in patients who recurred compared with those that remained disease-free. Thus, the mere presence of profoundly expanded numbers of vaccine-induced, self/tumor Ag-specific T cells cannot by themselves be used as a “surrogate marker” for vaccine efficacy. Further, the induction of even high levels of antitumor T cells may be insufficient to alter tumor progression.

SummaryLymphopenia is a serious consequence of HIV infection and the administration of cancer chemotherapeutic agents. Although growth factors can be administered to patients to increase circulating neutrophils, there is no effective method to stimulate CD8 + lymphocyte production in humans, in vivo. This report is the first to describe the administration of recombinant interleukin-7 to humans and demonstrates the ability of this cytokine to mediate selective increases in CD4 + and CD8 + lymphocytes along with a decrease in the percentage of CD4 + T-regulatory cells. These studies suggest an important role for interleukin-7 in the treatment of patients with lymphopenia. Keywordsinterleukin-7; regulatory T cells; human lymphocytes; lymphopoiesis Interleukin (IL) 7 is a 17.5 kd cytokine produced by a variety of stromal cells, as well as by keratinocytes, dendritic cells, neurons, and endothelial cells but is not produced by lymphocytes. 1,2 The IL-7 receptor contains a unique 75 kd α chain and a γ chain shared with 4,7,9,15,and 21. Homeostatic control of lymphocyte levels in mice seems to be dependent on the cytokine, IL-7. IL-7 receptor knockout mice exhibit thymic atrophy, arrest of T-cell development at the double positive stage, and severe lymphopenia. 3 Administration of IL-7 to mice results in an increase in thymic emigrants, increases in B and T cells, and increased recovery of T cells after cyclophosphamide administration or after bone marrow transplantation. 4-7 Transgenic mice overexpressing IL-7 exhibit expansion of immature B cells and can develop lymphoproliferative disorders. 8,9In vitro studies have suggested a role for IL-7 in human immune function. The addition of IL-7 to neonatal human thymic cultures increases the number of immature and mature T cells. 10 A mutation in the IL-7 receptor α chain in humans leads to an unusual form of combined immunodeficiency disease characterized by severe T-cell defects but normal B cells and natural Reprints: Steven A. Rosenberg, MD, PhD, Surgery Branch, National Cancer Institute, National Institutes of Health, CRC, Room 3-3940, 10 Center Drive, Bethesda, MD 20892-1201 (e-mail: sar@nih.gov MATERIALS AND METHODS PatientsAll patients were treated in the Surgery Branch, National Cancer Institute in a protocol approved by the Institutional Review Board, NCI. Eleven patients had metastatic melanoma and one (patient 7, Table 1) had metastatic sarcoma. All patients were HLA-A*0201 + and had measurable disease. Eligibility criteria included creatinine <1.4 mg/dL, liver function enzymes <3 times the normal limit, absolute neutrophil count >1000/mm 3 , absolute lymphocyte count >200/mm 3 , platelet counts >100,000/mm 3 , and coagulation parameters <1.5 times the upper limit of normal. Patients were not eligible if they had any form of immunosuppressive disease or had resting blood pressure >140/90. IL-7IL-7 (CYT 99-007) was produced according to good manufacturing practice and supplied to the National Cancer Institute under a Cooperative Research and Development Agreeme...