Overexposure to venetoclax is associated with prolonged-duration of neutropenia during venetoclax and azacitidine therapy in Japanese patients with acute myeloid leukemia.

PURPOSE: An observational study was conducted to evaluate the pharmacokinetics of venetoclax and its impact on the efficacy and safety for Japanese patients with acute myeloid leukemia (AML) treated with venetoclax and azacitidine therapy. METHODS: The association between the plasma concentration, after the first cycle of azacitidine and venetoclax therapy, and the efficacy and safety was evaluated in 33 patients with untreated or relapsed/refractory AML. RESULTS: Full dose of venetoclax was administered to all patients. Venetoclax treatment was 28 day long in 82% of patients; the relative dose intensity of azacitidine was 82%. Trough concentration was significantly higher among patients with complete remission (CR) and CR with incomplete hematologic recovery (CRi) than those with the morphologic leukemia-free state and partial remission, and no response groups (P = 0.01). Median duration of grade 3 neutropenia was 28 days (range 8-46 days). Area under the concentration-time curve (AUC0-24) was significantly higher among patients with protracted grade 3 neutropenia (≥ 28 days) than those with a shorter duration (< 28 days) (P = 0.03); multivariate analysis revealed that a higher AUC0-24 was a significant predictor of a longer duration of neutropenia (odds ratio 54.3, P = 0.007). CONCLUSION: Plasma concentrations of venetoclax were variable in Japanese patients with AML. Higher plasma concentrations were associated with CR/CRi and protracted grade 3 neutropenia. Therefore, it is essential to adjust the duration of venetoclax administration based on individual pharmacokinetic data to limit total drug exposure, reduce severe neutropenia, and achieve higher efficacy.

Prognostic impact of peripheral blood WT1 mRNA dynamics in patients with acute myeloid leukemia treated with venetoclax combination therapy.

BACKGROUND: Wilms' tumor gene 1 (WT1) mRNA quantification is a useful marker of measurable residual disease in acute myeloid leukemia (AML). However, whether monitoring the WT1 mRNA levels may predict the outcome of venetoclax (VEN) combination therapy in AML is not reported. This study aims to elucidate whether WT1 mRNA dynamics could predict long-term prognosis. METHODS: 33 patients with untreated or relapsed/refractory AML evaluated for peripheral blood WT1 dynamics in VEN combination therapy were analyzed. RESULTS: The median age was 73 years (range 39-87). Azacitidine was combined with VEN in 91% of patients. Overall, the median overall survival (OS) was 334 days (95% CI 210-482), and the complete remission (CR) plus CR with incomplete hematologic recovery rate was 59%. A 1-log reduction of WT1 mRNA values by the end of cycle 2 of treatment was associated with significantly better OS and event-free survival (EFS) (median OS 482 days vs. 237 days, p = 0.049; median EFS 270 days vs. 125 days, p = 0.02). The negativity of post-treatment WT1 mRNA value during the treatment was associated with significantly better OS and EFS (median OS 482 days vs. 256 days, p = 0.02; median EFS not reached vs. 150 days, p = 0.005). Multivariate analysis confirmed the significance of these two parameters as strong EFS predictors (HR 0.26, p = 0.024 and HR 0.15, p = 0.013, respectively). The increase in WT1 mRNA values was correlated with relapse. CONCLUSION: This study demonstrates that WT1 mRNA dynamics can be a useful marker for assessing long-term prognosis of VEN combination therapy for AML.

Acute Myeloid Leukemia Harboring the t(16;21)(p11;q22) Translocation Treated With Venetoclax Plus Azacitidine After Cord Blood Transplantation.

A 62-year-old female was diagnosed with acute myeloid leukemia (AML) with t(16;21)(p11;q22). She achieved complete hematological remission after induction therapy and underwent umbilical cord blood stem cell transplantation (CBT). At 150 days after the CBT, a bone marrow examination revealed relapse. We treated the patient with venetoclax plus azacitidine as salvage therapy. After five cycles of venetoclax and azacitidine therapy, the patient died due to disease progression. The prognosis of AML with t(16;21)(p11;q22) is very poor owing to the high rate of early relapse even after hematopoietic stem cell transplantation. Therefore, a novel therapeutic approach is required to improve patient outcomes.

Methotrexate-induced Transient Encephalopathy in an Adolescent and Young Adult Patient with Acute Lymphoblastic Leukemia.

A 17-year-old girl was diagnosed with acute lymphoblastic leukemia (ALL). After the administration of high-dose methotrexate (MTX) or intrathecal MTX, the patient experienced transient hemiparesis and motor aphasia. Diffusion-weighted magnetic resonance imaging showed a high-intensity lesion in the bilateral centrum semiovale, and a vasospasm was detected in the proximal segment of bilateral A1 on magnetic resonance angiography. Edaravone was administered, and leucovorin rescue treatment was continued; eventually, the patient's neurological symptoms completely resolved. This finding suggested that vasospasm might be a mechanism underlying MTX-induced transient encephalopathy in adolescent and young adult patients with ALL.

CD7-Positive Diffuse Large B-Cell Lymphoma Presenting as an Intranasal Tumor.

We report a case of a 74-year-old man with a cluster of differentiation (CD) 7-positive diffuse large B-cell lymphoma (DLBCL) in the right nasal cavity. Flow cytometry analyses showed CD7 and CD20 positivity in tumor cells. The patient received 6 cycles of R-CHOP plus local radiation therapy because positron emission tomography-computed tomography after R-CHOP revealed an intranasal lesion. The patient achieved complete remission (CR) after radiation therapy. The frequency of CD7-positive DLBCL is rare, and only 11 cases with follow-up of clinical course have been reported thus far. CR or partial response was noted in 8 of 11 cases after receiving rituximab combined with chemotherapy. In total, 9 of 12 cases involved the development of extranodal lesions, which occurred as an intranasal tumor in 3 cases. It is important to examine the clinical features by accumulation of further cases.

[Refractory CD20-positive peripheral T-cell lymphoma showing loss of CD20 expression after rituximab therapy and gain of CD20 expression after administration of vorinostat and gemcitabine].

A 79-year-old male patient presented with systemic lymphadenopathy. A lymph node biopsy revealed effacement of the normal nodal architecture with diffuse proliferation of medium-sized atypical lymphoid cells. Southern blot analyses demonstrated rearrangement of the T-cell receptor gene but not the immunoglobulin heavy chain gene. He was diagnosed with CD20-positive peripheral T-cell lymphoma (PTCL), NOS. Although he achieved partial remission after six cycles of R-CHOP, he relapse occurred after 2 months. CD20-negative conversion was confirmed in the lymph node, which was positive for CCR4, and the skin at the time of relapse. The patient received the GDP regimen as salvage therapy with the addition of vorinostat for skin involvement; however, he failed to respond, and the disease systemically progressed. Furthermore, he also exhibited progression in the skin after stopping vorinostat due to hematologic toxicity. A lymph node biopsy at progression revealed CD20 re-expression by immunohistochemistry. At progression, the patient received mogamulizumab but failed to respond, and he died owing to disease progression 8 months after relapse. In this case, we demonstrated CD20-negative conversion following rituximab and CD20-positive reversion after using vorinostat and gemcitabine.

Hypoxia-inducible microRNA-210 regulates the DIMT1-IRF4 oncogenic axis in multiple myeloma.

Multiple myeloma (MM) is characterized by the accumulation of a population of malignant plasma cells within the bone marrow and its microenvironment. A hypoxic niche is located within the microenvironment, which causes myeloma cells to become quiescent, anti-apoptotic, glycolytic, and immature. Cell heterogeneity may be related to distinct gene expression profiles under hypoxic and normoxic conditions. During hypoxia, myeloma cells acquire these phenotypes by downregulating interferon regulatory factor 4 (IRF4), an essential transcription factor in myeloma oncogenesis. To identify essential microRNAs and their targets regulated under hypoxic conditions, we undertook microRNA and cDNA microarray analyses using hypoxia-exposed primary MM samples and myeloma cell lines. Under hypoxia, only miR-210 was highly upregulated and was accompanied by direct downregulation of an 18S rRNA base methyltransferase, DIMT1. This inverse expression correlation was validated by quantitative RT-PCR for primary MM samples. We further determined that DIMT1 has an oncogenic potential as its knockdown reduced tumorigenicity of myeloma cells through regulation of IRF4 expression. Notably, by analyzing gene expression omnibus datasets in the National Center for Biotechnology Information database, we found that DIMT1 expression increased gradually with MM progression. In summary, by screening for targets of hypoxia-inducible microRNA-210, we identified DIMT1 as a novel diagnostic marker and therapeutic target for all molecular subtypes of MM.

Histone deacetylase inhibitors inhibit metastasis by restoring a tumor suppressive microRNA-150 in advanced cutaneous T-cell lymphoma.

Tumor suppressive microRNA (miR)-150 inhibits metastasis by combining with the C-C chemokine receptor 6 (CCR6) "seed sequence" mRNA of the 3'-untranslated region (3'-UTR) in advanced cutaneous T-cell lymphoma (CTCL). Because the histone deacetylase inhibitor (HDACI) vorinostat showed excellent outcomes for treating advanced CTCL, HDACIs may reduce the metastasis of CTCL by targeting miR-150 and/ or CCR6. To examine whether these candidate molecules are essential HDACI targets in advanced CTCL, we used the My-La, HH, and HUT78 CTCL cell lines for functional analysis because we previously demonstrated that their xenografts in NOD/Shi-scid IL-2γnul mice (CTCL mice) induced multiple metastases. We found that pan- HDACIs (vorinostat and panobinostat) inhibited the migration of CTCL cells and downregulated CCR6. The miRNA microarray analysis against CTCL cell lines demonstrated that these pan-HDACIs commonly upregulated 161 miRNAs, including 34 known tumor suppressive miRNAs such as miR-150. Although 35 miRNAs possessing the CCR6 "seed sequence" were included in these 161 miRNAs, miR-150 and miR-185-5p were downregulated in CTCL cells compared to in normal CD4+ T-cells. The transduction of 12 candidate miRNAs against CTCL cells revealed that miR-150 most efficiently inhibited their migration capabilities and downregulated CCR6. Quantitative reverse transcriptase-polymerase chain reaction demonstrated that miR-150 was downregulated in advanced but not early CTCL primary cases. Finally, we injected miR-150 or siCCR6 into CTCL mice and found that mouse survival was significantly prolonged. These results indicate that miR-150 and its target, CCR6, are essential therapeutic targets of pan-HDACIs in advanced CTCL with metastatic potential.

Downregulated expression of miR-155, miR-17, and miR-181b, and upregulated expression of activation-induced cytidine deaminase and interferon-α in PBMCs from patients with SLE.

OBJECTIVE: Recent studies on systemic lupus erythematosus (SLE) revealed that microRNAs (miRNAs or miRs) were involved in its pathogenesis. However, only a limited number of miRNAs have been examined. METHODS: We performed quantitative real-time reverse transcription-polymerase chain reaction analyses of peripheral blood mononuclear cells (PBMCs) obtained from 31 untreated SLE patients and 31 healthy subjects to examine the expression levels of miR-155, miR-17, and miR-181b, as well as those of activation-induced cytidine deaminase (AID) and interferon-α (IFN-α) messenger RNAs (mRNAs). We examined the relationship between miR-181b, AID, and IFN-α with a luciferase reporter assay. RESULTS: The expression levels of miR-155, miR-17, and miR-181b were significantly lower in SLE patients than those in healthy controls, whereas those of AID and IFN-α mRNAs were significantly higher in SLE patients than those in healthy controls. The expression levels of miR-155, miR-17, and miR-181b inversely correlated with those of AID and IFN-α mRNAs in SLE patients. The results of the luciferase reporter assay revealed that miR-181b negatively regulated AID and IFN-α. CONCLUSIONS: The results of the present study demonstrated for the first time that there is a differential expression and inverse correlation between the levels the miR-155, miR-17, and miR-181b and target molecules, AID and IFN-α mRNAs, in PBMCs of untreated SLE patients. These alterations may contribute to the pathogenesis of SLE.

MicroRNA-150 inhibits tumor invasion and metastasis by targeting the chemokine receptor CCR6, in advanced cutaneous T-cell lymphoma.

In this study, we show that microRNA-150 (miR-150) is significantly downregulated in advanced cutaneous T-cell lymphoma (CTCL), and that this downregulation is strongly associated with tumor invasion/metastasis. Inoculation of CTCL cell lines into nonobese diabetic/Shi-scid interleukin 2γ (IL-2γ) null mice led to CTCL cell migration to multiple organs; however, prior transfection of the cells with miR-150 substantially reduced the invasion/metastasis by directly downregulating CCR6, a specific receptor for the chemokine CCL20. We also found that IL-22 and its specific receptor subunit, IL22RA1, were aberrantly overexpressed in advanced CTCL, and that production of IL-22 and CCL20 was increased in cultured CTCL cells. IL22RA1 knockdown specifically reduced CCL20 production in CTCL cells, suggesting that IL-22 upregulation may activate the production of CCL20 and its binding to CCR6, thereby enhancing the multidirectional migration potential of CTCL cells. CTCL cells also exhibited nutrition- and CCL20-dependent chemotaxis, which were inhibited by miR-150 transfection or CCR6 knockdown. From these findings, we conclude that, in the presence of continuous CCR6 upregulation accompanied by miR-150 downregulation, IL-22 activation leads to continuous CCL20-CCR6 interaction in CTCL cells and, in turn, autocrine metastasis to distal organs. This suggests miR-150, CCL20, and CCR6 could be key targets for the treatment of advanced CTCL.

Bortezomib reduces the tumorigenicity of multiple myeloma via downregulation of upregulated targets in clonogenic side population cells.

Side population (SP) cells in cancers, including multiple myeloma, exhibit tumor-initiating characteristics. In the present study, we isolated SP cells from human myeloma cell lines and primary tumors to detect potential therapeutic targets specifically expressed in SP cells. We found that SP cells from myeloma cell lines (RPMI 8226, AMO1, KMS-12-BM, KMS-11) express CD138 and that non-SP cells include a CD138-negative population. Serial transplantation of SP and non-SP cells into NOD/Shi-scid IL-2γnul mice revealed that clonogenic myeloma SP cells are highly tumorigenic and possess a capacity for self-renewal. Gene expression analysis showed that SP cells from five MM cell lines (RPMI 8226, AMO1, KMS-12-BM, KMS-11, JJN3) express genes involved in the cell cycle and mitosis (e.g., CCNB1, CDC25C, CDC2, BIRC5, CENPE, SKA1, AURKB, KIFs, TOP2A, ASPM), polycomb (e.g., EZH2, EPC1) and ubiquitin-proteasome (e.g., UBE2D3, UBE3C, PSMA5) more strongly than do non-SP cells. Moreover, CCNB1, AURKB, EZH2 and PSMA5 were also upregulated in the SPs from eight primary myeloma samples. On that basis, we used an aurora kinase inhibitor (VX-680) and a proteasome inhibitor (bortezomib) with RPMI 8226 and AMO1 cells to determine whether these agents could be used to selectively target the myeloma SP. We found that both these drugs reduced the SP fraction, though bortezomib did so more effectively than VX-680 due to its ability to reduce levels of both phospho-histone H3 (p-hist. H3) and EZH2; VX-680 reduced only p-hist. H3. This is the first report to show that certain oncogenes are specifically expressed in the myeloma SP, and that bortezomib effectively downregulates expression of their products. Our approach may be useful for screening new agents with which to target a cell population possessing strong tumor initiating potential in multiple myeloma.

Safety and efficacy of low-dose liposomal amphotericin B as empirical antifungal therapy for patients with prolonged neutropenia.

BACKGROUND: Liposomal amphotericin B (L-AmB) is recommended as an empirical antifungal treatment for patients at increased risk of fungal infections although renal toxicity remains a clinical problem. We therefore conducted a pilot study to evaluate the safety and efficacy of low-dose L-AmB as an empirical antifungal therapy for patients with prolonged neutropenia. METHODS: High-risk patients with hematological malignancies were eligible to enroll in this study provided they had: exhibited neutropenia for at least 1 week; suffered from high-grade fever for 4 days despite treatment with a broad-spectrum antibacterial; and no identified fever-causing pathogen. Low-dose L-AmB (1 mg/kg) was administrated as empirical antifungal therapy. RESULTS: Sixteen patients were registered and, of these, data from the13 patients who did not receive allogeneic stem cell transplantation were analyzed. The median duration of low-dose L-AmB treatment was 8 days. Hypokalemia was seen in one patient: administration of potassium supplements for 10 days restored potassium levels to the normal range. A two-fold increase in creatinine levels was not found in any patients even those taking concomitant nephrotoxic drugs (e.g., amynoglycoside) during the study. One patient stopped receiving the drug due to an infusion-related adverse event. No patients showed breakthrough fungal infections or died during therapy or within 7 days after the end of the study. Increase in the L-AmB dose was necessary due to persistent fever in three patients who withdrew from the study. The satisfactory response rate for low-dose L-AmB was 69 %. CONCLUSION: This study suggests that low-dose L-AmB may be an effective option as empirical antifungal therapy for high-risk patients with febrile neutropenia.