Mutational analysis of DNMT3A improves the prognostic stratification of patients with acute myeloid leukemia.

Nucleophosmin1 (NPM1) mutations are the most frequently detected gene mutations in acute myeloid leukemia (AML) and are considered a favorable prognostic factor. We retrospectively analyzed the prognosis of 605 Japanese patients with de novo AML, including 174 patients with NPM1-mutated AML. Although patients with NPM1-mutated AML showed a high remission rate, this was not a favorable prognostic factor for overall survival (OS); this is contrary to generally accepted guidelines. Comprehensive gene mutation analysis showed that mutations in codon R882 of DNA methyltransferase 3A (DNMT3AR882 mutations) were a strong predicative factor indicating poor prognosis in all AML (p < 0.0001) and NPM1-mutated AML cases (p = 0.0020). Furthermore, multivariate analysis of all AML cases showed that DNMT3AR882 mutations and the co-occurrence of internal tandem duplication in FMS-like tyrosine kinase 3 (FLT3-ITD), NPM1 mutations, and DNMT3AR882 mutations (triple mutations) were independent factors predicting a poor prognosis related to OS, with NPM1 mutations being an independent factor for a favorable prognosis (hazard ratios: DNMT3AR882 mutations, 1.946; triple mutations, 1.992, NPM1 mutations, 0.548). Considering the effects of DNMT3AR882 mutations and triple mutations on prognosis and according to the classification of NPM1-mutated AML into three risk groups based on DNMT3AR882 /FLT3-ITD genotypes, we achieved the improved stratification of prognosis (p < 0.0001). We showed that DNMT3AR882 mutations are an independent factor for poor prognosis; moreover, when confounding factors that include DNMT3AR882 mutations were excluded, NPM1 mutations were a favorable prognostic factor. This revealed that ethnological prognostic discrepancies in NPM1 mutations might be corrected through prognostic stratification based on the DNMT3A status.

Primary diffuse large B cell lymphoma of the prostate in a patient with HIV infection.

Introduction: Primary prostate lymphomas are very rare; however, the incidence of malignant lymphoma is high among HIV-infected patients. Herein, we report a case of primary diffuse large B-cell lymphoma (DLBCL) of the prostate in an HIV-infected patient. Case presentation: A 47-year-old man presented with miction pain and back pain. Abdominal CT revealed a huge prostate mass extending to the left retroperitoneum. Serum sIL-2R level was abnormally high (2896 U/mL), whereas PSA level was normal. HIV antigen and antibody tests were positive. The patient was diagnosed with DLBCL after a prostate biopsy. Systemic treatments were administered; however, the tumor was refractory, and the patient died 9 months after diagnosis. Conclusion: Prostate malignant lymphomas are rare but should be considered in patients with enlarged prostates and normal PSA levels. It should be noted that HIV patients have a high incidence of malignant lymphomas.

Incidence and predictors of recurrent sick leave in survivors who returned to work after allogeneic hematopoietic cell transplantation.

BACKGROUND: Although rather favorable probabilities of return to work have been reported after allogeneic hematopoietic cell transplantation (allo-HCT), survivors often have difficulty continuing to work because of their immunocompromised status and diverse late effects after allo-HCT. We evaluated the incidence of and risk factors for recurrent sick leave in allo-HCT survivors after they initially returned to work. METHODS: We targeted allo-HCT survivors who were employed at diagnosis, aged 20-64 at survey, and survived for ≥ 2 years without relapse. Of the 1904 survivors who were informed of the study, 1148 returned the questionnaire (60%), and 1048 eligible participants were included in the overall analysis. In the present study that considered recurrent sick leave after return to work, we targeted 896 participants who returned to work at least once after allo-HCT. Participants stated if they had recurrent sick leave after returning to work and its reasons, as well as associated patient-, HCT/HCT center-, and work-related factors and clinical events after allo-HCT. A logistic regression analysis was conducted to explore correlated factors for recurrent sick leave. RESULTS: In survivors who returned to work, 30% required recurrent sick leave. The most frequent causes of recurrent leave were physical issues (72%), and analysis of free descriptions demonstrated that these were mainly associated with graft-versus-host disease, infection, or readmission. Other reasons included work-related issues such as gap between physical and working conditions. Multivariate analysis showed that cord blood transplantation, longer employment duration, and counseling from healthcare professionals were associated with a lower risk of recurrent leave. Readmission, immunosuppressant use, and symptoms involving the respiratory system, gut, and joints and muscles were associated with a higher risk. CONCLUSIONS: Our results drawn from a large cohort study should help healthcare professionals identify and assist at-risk patients. Multi-professional teams that provide continuous support and effective communication with the workplace are necessary to improve long-term outcomes after allo-HCT. IMPLICATIONS FOR CANCER SURVIVORS: In order to continue working after the initial return to work, it is important to receive counseling from healthcare professionals and obtain reasonable accommodation from workplace.

Type 1 diabetes mellitus after cord blood transplantation from an unrelated donor with a disease-sensitive haplotype.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT), a curative treatment for hematopoietic neoplasms, often causes various autoimmune disease-like conditions. In contrast, allo-HSCT-related type 1 diabetes mellitus is extremely rare. Herein, we report a case of allo-HSCT-related type 1 diabetes mellitus in a patient who had undergone cord blood transplantation (CBT) as a treatment for acute myeloid leukemia. The patient's human leukocyte antigen was replaced with the donor type after transplantation. The donor had a disease-sensitive haplotype. To the best of our knowledge, this is the first reported case of type 1 diabetes mellitus following CBT.

Allogeneic Hematopoietic Cell Transplantation for Patients with Relapsed Acute Promyelocytic Leukemia.

Although autologous hematopoietic cell transplantation (HCT) is an established therapy for patients with relapsed acute promyelocytic leukemia (APL) after returning to complete remission (CR), the role of allogeneic HCT remains unclear for treating relapsed APL. This study aimed to investigate allogeneic HCT outcomes in patients with relapsed APL, focusing particularly on those who underwent transplantation in non-CR and those who had relapsed after prior autologous HCT. We retrospectively analyzed Japanese nationwide transplantation registry data of patients with relapsed APL age ≥16 years who underwent allogeneic HCT between 2006 and 2020. A total of 195 patients were eligible for this analysis, including 69 who underwent transplantation in non-CR and 55 who relapsed after prior autologous HCT. The median duration of follow-up for survivors was 5.4 years. Multivariate analysis revealed that both non-CR at transplantation (hazard ratio [HR], 1.74; 95% confidence interval [CI], 1.12 to 2.71; P = .014) and prior autologous HCT (HR, 2.10; 95% CI, 1.28 to 3.44; P = .013) were associated with higher risks of overall mortality. The 5-year overall survival (OS) rates for patients who underwent transplantation in CR and non-CR were 58% and 39%, respectively (P = .085), if they did not have a history of prior autologous HCT. In the patients who had relapsed after prior autologous HCT, the 5-year OS rate was 47% for those who underwent allogeneic HCT in CR and 6% for those who did so in non-CR (P = .001). Allogeneic HCT still provides an opportunity for long-term survival for certain patients with relapsed APL for whom autologous HCT is unlikely to be effective. The dismal outcome of those with prior autologous HCT who underwent allogeneic HCT in non-CR poses a significant therapeutic challenge.

Serum high-density lipoprotein cholesterol level has a significant prognostic impact on outcomes of follicular lymphoma patients.

We investigated the potential of nutritional and inflammatory parameters as prognostic factors for follicular lymphoma (FL), and also examined the predictive value of the early progression of disease within 24 months of first-line chemo-immunotherapy (POD24). We retrospectively analyzed 46 patients with FL admitted to Teikyo University Hospital and treated with chemo-immunotherapy between May 2009 and July 2019. Physical characteristics, blood parameters, and markers or scores for consumptive/inflammatory and nutritional conditions were used as variables. Nine parameters correlated with poor overall survival (OS) in univariate analysis: An Eastern Cooperative Oncology Group (ECOG) scale performance status (PS) ≥2, five or more involved nodal sites, positive bone marrow (BM) involvement, a serum albumin level <3.5 g/dL, CRP >0.5 mg/dL, lactate dehydrogenase (LD) higher than the upper normal limit (UNL), high-density lipoprotein cholesterol (HDL-C) <40 mg/dL, modified Glasgow prognostic score of 1-2, and the geriatric nutritional risk index <82. In multivariate analysis, ECOG PS ≥2, positive BM involvement, and a serum HDL-C level <40 mg/dL remained significant for poor progression-free survival. One-year OS rate after receiving salvage chemotherapy was lower in the POD24 group (50%) and POD24 correlated with ECOG PS ≥2, positive BM involvement, a serum lactate dehydrogenase >UNL, and HDL-C <40 mg/dL by Fisher's exact test. These results indicate that low serum HDL-C levels appear to be important for predicting the risk of POD24 and the worse prognosis of FL.

The FLT3 internal tandem duplication mutation at disease diagnosis is a negative prognostic factor in myelodysplastic syndrome patients.

The role of the FMS-like tyrosine kinase 3 (FLT3) gene in acute myeloid leukemia (AML) has been well documented and the FLT3-internal tandem duplication (FLT3-ITD) mutation has been identified as a prognostic factor in AML. Due to its low incidence, the role of the FLT3 mutation remains unclear in myelodysplastic syndrome (MDS) patients. To investigate the impact of the FLT3-ITD status on the prognosis of MDS at diagnosis, we retrospectively analyzed 72 MDS patients admitted to Teikyo University Hospital. FLT3-ITD was examined by a reverse transcription-polymerase chain reaction using complementary DNA synthesized from mRNA extracted from bone marrow mononuclear cells at the diagnosis of MDS. Fifteen patients (20.8 %) were positive for FLT3-ITD and had significantly worse overall survival (OS) and progression-free survival (PFS) than patients who were negative (P < 0.001 and P < 0.001, respectively) in a multivariate analysis. We also investigated whether the Wilms' tumor gene-1 (WT-1) copy number was associated with the FLT3-ITD mutational status using data available on WT-1 from 57 patients. A WT-1 transcript copy number ≥50/µg total mRNA in peripheral blood was detected in 35 patients (61.4 %). All FLT3-ITD-positive patients showed WT-1 ≥50. The FLT3-ITD-positive group showed significantly higher WT-1 transcription levels than the negative group. These results indicate that the FLT3-ITD mutation has a prognostic impact at the diagnosis of MDS and is associated with a high level of WT-1.

Budd-Chiari Syndrome during Long-term Follow-up after Allogeneic Umbilical Cord Blood Transplantation.

A series of abdominal computed tomography scans of an asymptomatic 40-year-old woman with a history of umbilical cord blood transplantation (CBT) for leukemia at 19 years old revealed the long-term gradual development of a right hepatic vein thrombus and stenosis of the inferior vena cava, leading to a diagnosis of Budd-Chiari syndrome. The Budd-Chiari syndrome in this case might have been influenced by the patient's history of multiple liver abscesses after CBT and associated thrombus formation, in addition to the hormone replacement therapy with estradiol and dydrogesterone she was taking. This case provides insight into the development of Budd-Chiari syndrome.

Bilateral nephromegaly due to direct leukemic cell invasion in the initial and relapse phases of T-cell acute lymphoblastic leukaemia: A case report.

RATIONALE: T-cell acute lymphoblastic leukemia is a relatively uncommon disorder in adults. Kidneys are not frequently invaded by leukemic cells, and patients with adult ALL showing nephromegaly as an initial presentation are rare. PATIENT CONCERNS: A 54-year-old man was referred to our institution for mild anemia and thrombocytopenia. Laboratory tests showed bicytopenia with abnormal lymphoid cells in the peripheral blood and mild renal dysfunction. DIAGNOSIS: Ultrasonography and computed tomography (CT) revealed bilateral enlargement of the kidneys. [18F]-fluorodeoxyglucose positron emission tomography/CT demonstrated a strong increase in metabolic uptake in the bilateral kidneys. A kidney biopsy revealed a leukemia invasion into the parenchyma. Based on the lymphocytic repertoire, the patient's condition was diagnosed as T-cell acute lymphoblastic leukaemia. INTERVENTIONS: The patient received hyper-cyclophosphamide, vincristine, adriamycin, and dexamethasone and high-dose methotrexate and cytarabine as induction chemotherapy. After his leukemia relapsed, he received nelarabine as a second induction therapy and underwent haploidentical peripheral blood stem cell transplantation. OUTCOMES: Complete remission (CR) was achieved after chemotherapy. Chemotherapy also improved renal function associated with the normalization of bilateral nephromegaly. Repeated [18F]-fluorodeoxyglucose - positron emission tomography/CT posttreatment showedregression of metabolic uptake in the bilateral kidneys. The patient underwent cord blood transplantation at the first CR, but his leukemia relapsed 9 months later. At relapse, bilateral nephromegaly reappeared. Then, the second induction therapy induced CR for at least 10 months after induction therapy. LESSONS: Although rare, ALL in the initial and relapsed phases can be associated with bilateral nephromegaly and renal impairment due to the invasion of leukemic cells into the parenchyma with or without abnormal leukemic cells in circulation. Leukemia is an important differential diagnosis of renal impairment with bilateral nephromegaly.

Mutated GM-CSF-based CAR-T cells targeting CD116/CD131 complexes exhibit enhanced anti-tumor effects against acute myeloid leukaemia.

OBJECTIVES: As the prognosis of relapsed/refractory (R/R) acute myeloid leukaemia (AML) remains poor, novel treatment strategies are urgently needed. Clinical trials have shown that chimeric antigen receptor (CAR)-T cells for AML are more challenging than those targeting CD19 in B-cell malignancies. We recently developed piggyBac-modified ligand-based CAR-T cells that target CD116/CD131 complexes, also known as the GM-CSF receptor (GMR), for the treatment of juvenile myelomonocytic leukaemia. This study therefore aimed to develop a novel therapeutic method for R/R AML using GMR CAR-T cells. METHODS: To further improve the efficacy of the original GMR CAR-T cells, we have developed novel GMR CAR vectors incorporating a mutated GM-CSF for the antigen-binding domain and G4S spacer. All GMR CAR-T cells were generated using a piggyBac-based gene transfer system. The anti-tumor effect of GMR CAR-T cells was tested in mouse AML xenograft models. RESULTS: Nearly 80% of the AML cells predominant in myelomonocytic leukaemia were found to express CD116. GMR CAR-T cells exhibited potent cytotoxic activities against CD116+ AML cells in vitro. Furthermore, GMR CAR-T cells incorporating a G4S spacer significantly improved long-term in vitro and in vivo anti-tumor effects. By employing a mutated GM-CSF at residue 21 (E21K), the anti-tumor effects of GMR CAR-T cells were also improved especially in long-term in vitro settings. Although GMR CAR-T cells exerted cytotoxic effects on normal monocytes, their lethality on normal neutrophils, T cells, B cells and NK cells was minimal. CONCLUSIONS: GMR CAR-T cell therapy represents a promising strategy for CD116+ R/R AML.

Second allogeneic transplantation using umbilical cord blood for a patient with relapsed ALK+ anaplastic large cell lymphoma after allogeneic bone marrow transplantation in the era of ALK inhibitors: A case report.

RATIONALE: Anaplastic lymphoma kinase (ALK) + anaplastic large cell lymphoma (ALCL) is considered as a good prognosis lymphoma. However, in an extremely rare subset of patients, ALK+ ALCL with leukemic presentations is known to be chemotherapy-resistant. Although several novel therapies have been tested, the standard therapy for relapsed/refractory ALK+ ALCL has not been established yet. PATIENT CONCERNS: An 18-year-old female patient who had conventional chemotherapy- and Brentuximab Vedotin (BV)-resistant ALK+ ALCL with leukemic presentation. She was successfully treated with an ALK inhibitor, crizotinib. Crizotinib induced complete remission (CR) and bridged to allogeneic bone marrow transplantation (BMT). DIAGNOSIS: However, her ALCL relapsed on day 60 after BMT and she developed high grade fever and lymphadenopathy. INTERVENTION: Although crizotinib was given to the patient immediately after relapse, she developed grade 3 nausea and could not continue to take it. Then, we gave alectinib to the patient, which promptly induced sustained CR without any further chemotherapy. The patient received second stem cell transplantation using umbilical cord blood with myeloablative regimen in 2nd CR. OUTCOMES: The patient has been in CR under maintenance therapy of alectinib for more than 16 months. LESSONS: Both ALK inhibitors demonstrated drastic efficacy for our patient who had chemotherapy- and BV-resistant ALK+ ALCL with leukemic presentation. Alectinib showed less gastro-intestinal toxicity than crizotinib and the patient was able to take it even at the relatively early phase of stem cell transplantation.

Functional expression cloning of molecules inducing CD34 expression in bone marrow-derived stromal myofibroblasts.

We have previously shown a fraction of stromal fibroblasts/myofibroblasts (Fibs) from leukemic bone marrow cells expresses leukemia-specific transcripts along with hematopoietic and Fib-related markers. Normal bone marrow-derived Fibs (nFibs) do not express CD34 or CD45; however, nFibs may express hematopoietic markers with some specific stimulations. CD34 expression was detected in nFib cultures following the addition of a culture supernatant of blood mononuclear cells stimulated with phytohemagglutinin (PHA)-P. To identify the molecules responsible for inducing CD34 expression in nFibs, cDNA clones were isolated using functional expression cloning with a library constructed from PHA-P-stimulated human blood mononuclear cells. Positive clones inducing CD34 transcription in nFibs were selected. We confirmed that an isolated positive cDNA clone encoded human interleukin (IL)-1 beta (ß). CD34 expression was observed in the nFib cultures with recombinant human (rh) IL-1ß protein. And CD34 transcription was suppressed when a rhIL-1ß neutralizing antibody was added to the IL-1ß-stimulated nFib cultures. nFibs expressed gp130 and IL-6 receptors, and CD45 expression was detected in nFibs cultured with rhIL-1ß and rhIL-6. Chronic myelogenous leukemia (CML) cells reportedly respond well to IL-1ß. When CML-derived Fibs were cultured with rhIL-1ß and rhIL-6, CD45-positive cells increased in number. Cell fate may be influenced by an external specific stimulation without gene introduction.

Gemtuzumab ozogamicin monotherapy prior to stem cell infusion induces sustained remission in a relapsed acute myeloid leukemia patient after allogeneic stem cell transplantation: A case report.

RATIONALE: Patients with relapsed acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) have poor prognosis. Many patients are not eligible for 2nd HSCT due to organ dysfunction or other complications that prevent them from tolerating conditioning chemotherapy. In those ineligible patients for 2nd HSCT with myeloablative conditioning regimen, reduced intensity conditioning (RIC) are often used. RIC regimens are less toxic but has a less direct anti-tumor efficacy so that RIC regimens are not suitable for the patients with high tumor burden. To overcome this dilemma, Gemtuzumab Ozogamicin (GO) has been used as a part of RIC regimens to add anti-tumor efficacy. We report here a relapsed AML patient who was treated with GO monotherapy followed by stem cell infusion. PATIENT CONCERNS: A 25-year-old male with AML experienced relapse 9 months after allo-HSCT. DIAGNOSIS: Since he had mild renal and cardiac dysfunction and his AML did not progress rapidly, we decided not to give him an intensive chemotherapy. However, after azacitidine (AZA) and donor lymphocyte infusion therapy, his leukemic blasts did not decrease. INTERVENTIONS: Originally, we had planned to proceed with a 2nd allo-HSCT with RIC regimen that consisted of fludarabine, melphalan and fractionated GO (3 mg/m/dose) on day -21, -18, and -15. However, the patient developed appendicitis after the last dose of GO when his neutrophil was 0 cells/µl. Based on his medical acuity, we terminated the rest of the patients conditioning regimen and the patient did not receive any further chemotherapeutics. The patient was still infused with peripheral blood stem cells from the donor on day 0. OUTCOMES: His appendicitis was resolved by antibiotics without surgery. His AML has been in CR more than 18 months under AZA maintenance therapy. LESSONS: GO monotherapy could be a conditioning regimen of 2nd allo HSCT from the same donor as the first HSCT for relapsed AML patients.

Modulating TNFα activity allows transgenic IL15-Expressing CLL-1 CAR T cells to safely eliminate acute myeloid leukemia.

BACKGROUND: C-type lectin-like molecule 1 (CLL-1) is highly expressed in acute myeloid leukemia (AML) but is absent in primitive hematopoietic progenitors, making it an attractive target for a chimeric antigen receptor (CAR) T-cell therapy. Here, we optimized our CLL-1 CAR for anti-leukemic activity in mouse xenograft models of aggressive AML. METHODS: First, we optimized the CLL-1 CAR using different spacer, transmembrane and costimulatory sequences. We used a second retroviral vector to coexpress transgenic IL15. We measured the effects of each construct on T cell phenotype and sequential (recursive) co culture assays with tumor cell targets to determine the durability of the anti tumor activity by flow cytometry. We administered CAR T cells to mice engrafted with patient derived xenografts (PDX) and AML cell line and determined anti tumor activity by bioluminescence imaging and weekly bleeding, measured serum cytokines by multiplex analysis. After euthanasia, we examined formalin-fixed/paraffin embedded sections. Unpaired two-tailed Student's t-tests were used and values of p<0.05 were considered significant. Survival was calculated using Mantel-Cox log-rank test. RESULTS: In vitro, CLL-1 CAR T cells with interleukin-15 (IL15) were less terminally differentiated (p<0.0001) and had superior expansion compared with CD28z-CD8 CAR T cells without IL15 (p<0.001). In both AML PDX and AML cell line animal models, CLL-1 CAR T coexpressing transgenic IL15 initially expanded better than CD28z-CD8 CAR T without IL15 (p<0.0001), but produced severe acute toxicity associated with high level production of human tumor necrosis factor α (TNFα), IL15 and IL2. Histopathology showed marked inflammatory changes with tissue damage in lung and liver. This acute toxicity could be managed by two strategies, individually or in combination. The excessive TNF alpha secretion could be blocked with anti-TNF alpha antibody, while excessive T cell expansion could be arrested by activation of an inducible caspase nine safety switch by administration of dimerizing drug. Both strategies successfully prolonged tumor-free survival. CONCLUSION: Combinatorial treatment with a TNFα blocking antibody and subsequent activation of the caspase-9 control switch increased the expansion, survival and antileukemic potency of CLL-1 CAR T-cells expressing transgenic IL15 while avoiding the toxicities associated with excessive cytokine production and long-term accumulation of activated T-cells.

The prognostic impact of FLT3-ITD, NPM1 and CEBPa in cytogenetically intermediate-risk AML after first relapse.

We evaluated the impact of FLT3-ITD, NPM1 mutations, and double mutant CEBPa (dmCEBPa) on overall survival (OS) after relapse in patients with cytogenetically intermediate-risk acute myeloid leukemia (AML) who were treated with chemotherapy alone in the first remission (CR1). Patients aged 16-65 years diagnosed with cytogenetically intermediate-risk AML, and who achieved CR1 were included. We retrospectively analyzed FLT3-ITD, NPM1 mutations and CEBPa using samples obtained at diagnosis, which therefore did not affect the therapeutic decisions. Among 235 patients who had achieved CR1, 152 relapsed, and 52% of them achieved second CR. The rate of achieving second CR was significantly higher (85%) in those with dmCEBPa. Patients with FLT3-ITD had significantly worse OS after relapse than those without (19% vs 41%, p = 0.002), while OS was comparable between patients with and without NPM1 mutations (37% vs 34%, p = 0.309). Patients with dmCEBPa had improved OS than those without (61% vs 32%, p = 0.006). By multivariate analysis, FLT3-ITD was independently associated with worse OS after relapse [hazard ratio (HR) 1.99, 95% CI 1.27-3.12, p = 0.003], and dmCEBPa with improved OS (HR 0.40, 95% CI 0.17-0.93, p = 0.033). Our data show that screening for these mutations at diagnosis is useful for facilitating effective therapeutic decision-making even after relapse.

CD7 CAR T Cells for the Therapy of Acute Myeloid Leukemia.

Chimeric antigen receptor (CAR) T cell therapy for the treatment of acute myeloid leukemia (AML) has the risk of toxicity to normal myeloid cells. CD7 is expressed by the leukemic blasts and malignant progenitor cells of approximately 30% of AML patients but is absent on normal myeloid and erythroid cells. Since CD7 expression by malignant blasts is also linked with chemoresistance and poor outcomes, targeting this antigen may be beneficial for this subset of AML patients. Here, we show that expression of a CD7-directed CAR in CD7 gene-edited (CD7KO) T cells effectively eliminates CD7+ AML cell lines, primary CD7+ AML, and colony-forming cells but spares myeloid and erythroid progenitor cells and their progeny. In a xenograft model, CD7 CAR T cells protect mice against systemic leukemia, prolonging survival. Our results support the feasibility of using CD7KO CD7 CAR T cells for the non-myeloablative treatment of CD7+ AML.