Spacer Length Modification Facilitates Discrimination between Normal and Neoplastic Cells and Provides Clinically Relevant CD37 CAR T Cells.

Despite the remarkable initial efficacy of CD19 chimeric Ag receptor T (CAR-T) cell therapy, a high incidence of relapse has been observed. To further increase treatment efficacy and reduce the rate of escape of Ag-negative cells, we need to develop CAR-T cells that target other Ags. Given its restricted expression pattern, CD37 was considered a preferred novel target for immunotherapy in hematopoietic malignancies. Therefore, we designed a CD37-targeting CAR-T (CD37CAR-T) using the single-chain variable fragment of a humanized anti-CD37 Ab, transmembrane and intracellular domains of CD28, and CD3ζ signaling domains. High levels of CD37 expression were confirmed in B cells from human peripheral blood and bone marrow B cell precursors at late developmental stages; by contrast, more limited expression of CD37 was observed in early precursor B cells. Furthermore, we found that human CD37CAR-T cells with longer spacer lengths exhibited high gene transduction efficacy but reduced capacity to proliferate; this may be due to overactivation and fratricide. Spacer length optimization resulted in a modest transduction efficiency together with robust capacity to proliferate. CD37CAR-T cells with optimized spacer length efficiently targeted various CD37+ human tumor cell lines but had no impact on normal leukocytes both in vitro and in vivo. CD37CAR-T cells effectively eradicated Raji cells in xenograft model. Collectively, these results suggested that spacer-optimized CD37CAR-T cells could target CD37-high neoplastic B cells both in vitro and in vivo, with only limited interactions with their normal leukocyte lineages, thereby providing an additional promising therapeutic intervention for patients with B cell malignancies.

[Severe neuropsychiatric disorder developing during busulfan-containing regimen for stem cell transplantation].

Here we describe two patients that required interruption of a busulfan (BU) containing conditioning regimen due to severe mental disorder before stem cell transplantation. The first patient was a 66-year-old man scheduled for unrelated peripheral blood stem cell transplantation with fludarabine/BU conditioning for myelodysplastic syndrome. He received 9.6 mg/kg BU and developed hallucinations that worsened the next day. BU was stopped on the final day, but the patient became comatose (grade 4). He recovered the next day. The second patient was a 69-year-old man scheduled for autologous peripheral blood stem cell transplantation with thiotepa (TT)/BU conditioning for cerebral nervous system relapse of mantle cell lymphoma. He received 12.8 mg/kg BU and developed hallucinations. His mental symptoms worsened on the next day, and thus administration was stopped on the second day of TT. His symptoms improved the next day. Both patients were over 65 years old, and their psychiatric symptoms worsened 1-2 days after the final dose of BU. Our findings suggest that BU may cause psychiatric disorders in elderly patients. When performing BU conditioning, it may be necessary to avoid azole antifungal medication and acetaminophen and to reduce the dose or perform therapeutic dose monitoring for elderly patients.

Composite CD79A/CD40 co-stimulatory endodomain enhances CD19CAR-T cell proliferation and survival.

Adoptively transferred CD19 chimeric antigen receptor (CAR) T cells have led to impressive clinical outcomes in B cell malignancies. Beyond induction of remission, the persistence of CAR-T cells is required to prevent relapse and provide long-term disease control. To improve CAR-T cell function and persistence, we developed a composite co-stimulatory domain of a B cell signaling moiety, CD79A/CD40, to induce a nuclear translocating signal, NF-κB, to synergize with other T cell signals and improve CAR-T cell function. CD79A/CD40 incorporating CD19CAR-T cells (CD19.79a.40z) exhibited higher NF-κB and p38 activity upon CD19 antigen exposure compared with the CD28 or 4-1BB incorporating CD19CAR-T cells (CD19.28z and CD19.BBz). Notably, we found that CD19.79a.40z CAR-T cells continued to suppress CD19+ target cells throughout the co-culture assay, whereas a tendency for tumor growth was observed with CD19.28z CAR-T cells. Moreover, CD19.79a.40z CAR-T cells exhibited robust T cell proliferation after culturing with CD19+ target cells, regardless of exogenous interleukin-2. In terms of in vivo efficiency, CD19.79a.40z demonstrated superior anti-tumor activity and in vivo CAR-T cell proliferation compared with CD19.28z and CD19.BBz CD19CAR-T cells in Raji-inoculated mice. Our data demonstrate that the CD79A/CD40 co-stimulatory domain endows CAR-T cells with enhanced proliferative capacity and improved anti-tumor efficacy in a murine model.

End-of-Life Care of Acute Myeloid Leukemia Compared with Aggressive lymphoma in Patients Who Are Eligible for Intensive Chemotherapy: An Observational Study in a Japanese Community Hospital.

Background: Patients with hematological malignancies (HMs) are reported to receive more aggressive care at the end of life (EOL) than patients with solid tumors. However, the reasons behind this occurrence are not fully understood. Objectives: To examine whether the care at EOL for HMs is mainly because of the disease characteristics or hematologists' attitudes and systems of care, we compared the EOL care of patients with acute myeloid leukemia (AML) and diffuse large B cell lymphoma (DLBCL). Design: We retrospectively analyzed the EOL care of patients with AML and DLBCL younger than 80 years who were receiving combination chemotherapy at a city hospital in Japan. Results: Fifty-nine patients with AML and 65 with DLBCL were included. Those with AML received chemotherapy more often within their last 30 days (48% vs. 19%, p < 0.001) and 14 days (37% vs. 1.5%, p < 0.001) of life, and consulted the palliative team less frequently (5.3% vs. 29%, p < 0.001). In the last 3 years, the mortality rate in hematological wards decreased from 74% to 29% in the DLBCL group, but only from 95% to 90% in the AML group. In multivariate analysis, AML (odds ratio [OR] 0.065) and death before 2018 (OR, 0.077) were significant factors associated with reduced referrals to specialized palliative teams. Conclusion: Patients with AML tend to have lesser access to specialized palliative care and fewer options for their place of death than those with DLBCL. Detailed EOL care plans are needed for these patients, considering the characteristics of the disease.

A Retrospective Analysis of R-MPV Plus Response-adapted Whole-brain Radiotherapy for Elderly Patients with Primary Central Nervous System Lymphoma.

Objective Few reports have described the real-world outcomes of rituximab, methotrexate (MTX), procarbazine, and vincristine (R-MPV) plus response-adapted whole-brain radiotherapy (WBRT) for elderly patients with primary central nervous system lymphoma (PCNSL). We evaluated the outcome of this regimen. Methods We evaluated >60-year-old patients with newly diagnosed PCNSL who received R-MPV plus WBRT from January 2010 to December 2019 at Toyohashi Municipal Hospital. The patients' characteristics, regimen enforcement, response rate, survival, and toxicity were analyzed. Patients Ten patients were consecutively enrolled. Their median age was 69 years old, and 60% had a performance status of 3 or 4 before induction therapy. Results Seven patients achieved a complete response after induction, and all 10 patients achieved a complete response after consolidation. Seven received reduced-dose WBRT at 23.4 Gy, and 2 received WBRT at 45 Gy. The median follow-up was 44.4 months; the 3-year progression-free survival and overall survival rates were 60% and 80%, respectively; and the cumulative incidence of relapse was 40%. The incidence of symptomatic delayed neurotoxicity was 70%. Of the 7 patients who received reduced-dose WBRT, 4 (57%) developed delayed neurotoxicity, including 1 severely affected patient. Only one patient survived without relapse and delayed neurotoxicity. The ratio of patients who developed relapse or delayed neurotoxicity that impaired daily life was 33% and 100% in the MTX high- and low-intensity groups, respectively. Conclusion This regimen in elderly patients is unsatisfactory because of delayed neurotoxicity. We should consider maintaining an adequate MTX intensity, postponing or minimizing WBRT, and choosing high-dose consolidation therapy for select patients.

Downregulation of HLA class II is associated with relapse after allogeneic stem cell transplantation and alters recognition by antigen-specific T cells.

Genomic deletion of donor-patient-mismatched HLA alleles in leukemic cells is a major cause of relapse after allogeneic hematopoietic stem cell transplantation (HSCT). Mismatched HLA is frequently lost as an individual allele or a whole region in HLA-class I, however, it is downregulated in HLA-class II. We hypothesized that there might be a difference in T cell recognition capacity against epitopes associated with HLA-class I and HLA-class II and consequently such allogeneic immune pressure induced HLA alterations in leukemic cells. To investigate this, we conducted in vitro experiments with T cell receptor-transduced T (TCR-T) cells. The cytotoxic activity of NY-ESO-1-specific TCR-T cells exhibited similarly against K562 cells with low HLA-A*02:01 expression. However, we demonstrated that the cytokine production against low HLA-DPB1*05:01 expression line decreased gradually from the HLA expression level approximately 2-log lower than normal expressors. Using sort-purified leukemia cells before and after HSCT, we applied the next-generation sequencing, and revealed that there were several marked downregulations of HLA-class II alleles which demonstrated consistently low expression from pre-transplantation. The marked downregulation of HLA-class II may lead to decreased antigen recognition ability of antigen-specific T cells and may be one of immune evasion mechanism associated with HLA-class II downregulation.

Staurosporine and venetoclax induce the caspase-dependent proteolysis of MEF2D-fusion proteins and apoptosis in MEF2D-fusion (+) ALL cells.

MEF2D-fusion (M-fusion) genes are newly discovered recurrent gene abnormalities that are detected in approximately 5 % of acute lymphoblastic leukemia (ALL) cases. Their introduction to cells has been reported to transform cell lines or increase the colony formation of bone marrow cells, suggesting their survival-supporting ability, which prompted us to examine M-fusion-targeting drugs. To identify compounds that reduce the protein expression level of MEF2D, we developed a high-throughput screening system using 293T cells stably expressing a fusion protein of MEF2D and luciferase, in which the protein expression level of MEF2D was easily measured by a luciferase assay. We screened 3766 compounds with known pharmaceutical activities using this system and selected staurosporine as a potential inducer of the proteolysis of MEF2D. Staurosporine induced the proteolysis of M-fusion proteins in M-fusion (+) ALL cell lines. Proteolysis was inhibited by caspase inhibitors, not proteasome inhibitors, suggesting caspase dependency. Consistent with this result, the growth inhibitory effects of staurosporine were stronger in M-fusion (+) ALL cell lines than in negative cell lines, and caspase inhibitors blocked apoptosis induced by staurosporine. We identified the cleavage site of MEF2D-HNRNPUL1 by caspases and confirmed that its caspase cleavage-resistant mutant was resistant to staurosporine-induced proteolysis. Based on these results, we investigated another Food and Drug Administration-approved caspase activator, venetoclax, and found that it exerted similar effects to staurosporine, namely, the proteolysis of M-fusion proteins and strong growth inhibitory effects in M-fusion (+) ALL cell lines. The present study provides novel insights into drug screening strategies and the clinical indications of venetoclax.

Artificial T Cell Adaptor Molecule-Transduced TCR-T Cells Demonstrated Improved Proliferation Only When Transduced in a Higher Intensity.

An artificial T cell adaptor molecule (ATAM) was generated to improve persistence of T cell receptor (TCR) gene-transduced T (TCR-T) cells compared to such persistence in a preceding study. ATAMs are gene-modified CD3ζ with the intracellular domain of 4-1BB inserted in the middle of CD3ζ. NY-ESO-1 TCR-T cells transduced with an ATAM with two separated virus vectors demonstrated superior proliferation upon antigen stimulation. To further develop clinically applicable ATAM-transduced TCR-T cells, we attempted to make a single virus vector to transduce the TCR and ATAM simultaneously. Because we failed to observe improved proliferation capacity upon stimulation after one virus vector (1vv) transduction, we compared TCR-T cells transduced with 1vv and two virus vector (2vv) methods to elucidate the reason. In Jurkat reporter cells, an ATAM transduced by the 2vv method demonstrated a higher intensity than by the 1vv method, and the ATAM intensity was associated with increased nuclear factor κB (NF-κB) signals upon stimulation. In ATAM-transduced primary T cells, a transduced ATAM by the 2vv method showed higher intensity and better proliferation. ATAM-transduced TCR-T cells demonstrated improved proliferation only when the ATAM was transduced at a higher intensity. To create a simpler transduction method, we need to develop a strategy to make a higher ATAM expression to prove the efficacy of ATAM transduction in TCR-T therapy.

Case Report: Disseminated Talaromyces (Penicillium) marneffei and Mycobacterium tuberculosis Coinfection in a Japanese Patient with Acquired Immunodeficiency Syndrome.

Talaromyces marneffei is a dimorphic fungus endemic mainly in southeast and south Asia. It causes severe mycosis, usually in immunocompromised individuals, such as those with human immunodeficiency virus (HIV) infection. Concomitant infection with T. marneffei and other opportunistic pathogens is plausible because the majority of T. marneffei infections occur in patients with advanced HIV infection. Nonetheless, coinfection in the same site has rarely been reported, and poses a considerable diagnostic and therapeutic challenge. We report the case of an HIV-infected Japanese patient who had lived in Thailand for 6 years. The patient developed T. marneffei and Mycobacterium tuberculosis coinfection, and both pathogens were isolated from the same sites: a blood specimen and a lymph node aspirate. Clinicians should be aware of concomitant infection with T. marneffei and other pathogens in patients with advanced HIV disease who are living in or who have visited endemic areas.

A multicenter phase 2 study of empirical low-dose liposomal amphotericin B in patients with refractory febrile neutropenia.

Invasive fungal infection (IFI) is a major life-threatening problem encountered by patients with hematological malignancies receiving intensive chemotherapy. Empirical antifungal agents are therefore important. Despite the availability of antifungal agents for such situations, the optimal agents and administration methods remain unclear. We conducted a prospective phase 2 study of empirical 1 mg/kg/day liposomal amphotericin B (L-AMB) in 80 patients receiving intensive chemotherapy for hematological malignancies. All enrolled patients were high-risk and had recurrent prolonged febrile neutropenia despite having received broad-spectrum antibacterial therapy for at least 72 hours. Fifty-three patients (66.3 %) achieved the primary endpoint of successful treatment, thus exceeding the predefined threshold success rate. No patients developed IFI. The treatment completion rate was 73.8 %, and only two cases ceased treatment because of adverse events. The most frequent events were reversible electrolyte abnormalities. We consider low-dose L-AMB to provide comparable efficacy and improved safety and cost-effectiveness when compared with other empirical antifungal therapies. Additional large-scale randomized studies are needed to determine the clinical usefulness of L-AMB relative to other empirical antifungal therapies.

The Efficacy of an Oral Elemental Diet in Patients Undergoing Hematopoietic Stem Cell Transplantation.

Objective Conditioning regimens for hematopoietic stem cell transplantation (HSCT) are well known to cause severe gastrointestinal toxicities that often disturb the oral intake of the patients followed by poor nutrition and life-threatening infection. An oral elemental diet (ED) is an easily consumed and assimilated form of liquid nutrients mainly composed of amino acids. It alleviates the digestive loading from the intestine and is mainly used for enteral nutritional support in patients with Crohn's disease. We herein report, for the first time, the efficacy of ED for patients undergoing HSCT. Methods We evaluated the efficacy of ED in a prospective cohort study. The primary endpoint for this study was the hospitalization period. The secondary endpoint was the occurrence of oral mucositis, nausea, diarrhea and fever. Patients A total of 73 patients were consecutively enrolled between March 2011 and March 2013. Twenty-three patients underwent autologous HSCT and 50 patients underwent allogeneic HSCT. The first 21 patients did not receive ED (non-ED group; NEG) while in the successive 52 patients (ED group; EG), oral ED was started before conditioning and was continued until 28 days after transplantation. Results The patient characteristics were similar between the two groups. The mean duration of ED administration for EG was 28.7 days (range, 3-37 days), and the mean total-dose of ED administration was 1904 g (range, 240-2,960 g). The median hospitalization period was significantly shorter in EG compared to NEG, (34 days vs. 50 days; p=0.007). Grade 3-4 oral mucositis occurred less in EG than NEG (25% vs. 48%; p=0.06). Conclusion Oral ED may promote an early mucosal recovery and thereby shorten the duration of hospitalization.

Epidemiological and pathobiological profiles of Clostridium perfringens infections: review of consecutive series of 33 cases over a 13-year period.

BACKGROUND: Although Clostridium perfringens (C. perfringens) is well known as the causative agent of several forms of enteric disease, precise epidemiological and pathobiological aspects are still unknown. METHODS: We retrospectively reviewed the culture results of samples collected in our hospital from 2001 through 2013. In addition, for the detection and toxinogenic typing of C. perfringens, polymerase-chain-reaction amplification (PCR)-based rapid analysis was performed in 6 cases using DNA extracted from paraffin-embedded tissues. RESULTS: A total of 35 samples from 33 cases were positive for C. perfringens, representing an incidence of 0.017% (35/205, 114). Among 33 patients, 21 patients manifested sepsis and 7 patients had bacteremia. One of the septic cases was complicated by fatal intravascular hemolysis and thus, the prevalence was estimated at 3.0% among C. perfringens infections (1/33). The direct causative disease or state for C. perfringens infection was identified in 18 patients: surgery or intervention for cancers, 8 patients; chemotherapy for cancer, 2 patients; surgery or intervention for non-neoplastic disease, 6 patients; liver cirrhosis, 3 patients, etc. PCR-based toxinogenic typing of C. perfringens detected the alpha-toxin gene only in tissue from a patient who died of massive hemolysis; none of the toxin genes could be amplified in the other 5 cases examined. CONCLUSIONS: The prevalence of overt C. perfringens infection is low, but upon detection, infected patients should be carefully monitored for fatal acute hemolysis caused by type A C. perfringens. Furthermore, PCR-based rapid detection of C. perfringens and toxinogenic typing by archival pathological material is applicable as a diagnostic tool.

Upfront autologous stem-cell transplantation with melphalan, cyclophosphamide, etoposide, and dexamethasone (LEED) in patients with newly diagnosed primary central nervous system lymphoma.

Treatment of primary central nervous system lymphoma (PCNSL) improved in recent years. However, the high neurotoxicity and low survival rates associated with this condition remain unresolved. We report 13 consecutive patients with PCNSL for whom upfront melphalan, cyclophosphamide, etoposide, and dexamethasone (known as LEED) followed by autologous stem-cell transplantation (ASCT) was planned at the Anjo Kosei Hospital. All patients were pathologically diagnosed with diffuse large B-cell lymphoma and were negative for human immunodeficiency virus. All patients were to receive three cycles of high-dose methotrexate-based induction chemotherapy, two cycles of high-dose AraC-based chemotherapy, and LEED followed by ASCT. All 13 patients achieved a partial response, and the 3-year overall survival (OS) rate was 76.2 %. Seven of the 13 patients were alive at the last follow-up, without any adverse events, including neurotoxicity. Six of the 13 (46.2 %) patients underwent ASCT and the 3-year OS rate was 80.0 %. Although this study included only a limited number of patients, these preliminary signs of efficacy and tolerability merit further consideration. To make further improvements in survival, the rate of patients undergoing ASCT should be increased. Other prospective studies involving greater numbers of patients are required to confirm these findings.