Novel MAGIC composite scores using both clinical symptoms and biomarkers best predict treatment outcomes of acute GVHD.

ABSTRACT: Acute graft-versus-host disease (GVHD) grading systems that use only clinical symptoms at treatment initiation such as the Minnesota risk identify standard and high-risk categories but lack a low-risk category suitable to minimize immunosuppressive strategies. We developed a new grading system that includes a low-risk stratum based on clinical symptoms alone and determined whether the incorporation of biomarkers would improve the model's prognostic accuracy. We randomly divided 1863 patients in the Mount Sinai Acute GVHD International Consortium (MAGIC) who were treated for GVHD into training and validation cohorts. Patients in the training cohort were divided into 14 groups based on similarity of clinical symptoms and similar nonrelapse mortality (NRM); we used a classification and regression tree (CART) algorithm to create three Manhattan risk groups that produced a significantly higher area under the receiver operating characteristic curve (AUC) for 6-month NRM than the Minnesota risk classification (0.69 vs 0.64, P = .009) in the validation cohort. We integrated serum GVHD biomarker scores with Manhattan risk using patients with available serum samples and again used a CART algorithm to establish 3 MAGIC composite scores that significantly improved prediction of NRM compared to Manhattan risk (AUC, 0.76 vs 0.70, P = .010). Each increase in MAGIC composite score also corresponded to a significant decrease in day 28 treatment response (80% vs 63% vs 30%, P < .001). We conclude that the MAGIC composite score more accurately predicts response to therapy and long-term outcomes than systems based on clinical symptoms alone and may help guide clinical decisions and trial design.

Prognostic Factors of Adult Hemophagocytic Lymphohistiocytosis and Clinical Utility of HLH-2004 Diagnostic Criteria and HScore: A Real-World Multicenter Study from Thailand.

INTRODUCTION: Adult hemophagocytic lymphohistiocytosis (HLH) is a rare disease with a dismal prognosis. Early diagnosis and prompt management are necessary for improved outcomes. METHODS: This multicenter retrospective study investigated the etiologies, survival, and prognostic factors of HLH, including the utility of HLH-2004 criteria and HScore in real-life clinical practice. RESULTS: A total of 147 HLH patients were identified by using a combination of hemophagocytosis identification in bone marrow and the HLH-related international classification disease-10. A total of 116 (78.9%) patients fulfilled the HLH diagnosis by HScore, while 91 (61.9%) patients fulfilled 5 of 8 HLH-2004 criteria. In Thailand, the clinical application of HLH-2004 criteria needed to be reduced from 8 to 6 due to a lack of sCD25 and natural killer cell activity tests. Using the adapted HLH-2004 with a cutoff value of 4 resulted in 132 (89.9%) cases meeting the diagnostic criteria. Among these 132 confirmed HLH patients by using adapted HLH-2004, HLH was triggered by infection (29.5%), autoimmune disease (12.9%), malignancy (40.9%), and unknown cause (16.7%). Median overall survival of HLH patients was extremely short (67 days). Ferritin >6,000 µg/L, HLH from infection, malignancy, and unknown etiology were demonstrated as independent prognostic factors for inferior survival (hazard ratio [HR] 2.47; 95% confidence interval [CI] 1.39-4.37, HR 4.69; 95% CI 1.38-15.92, HR 6.09; 95% CI 1.84-20.14, and HR 6.02; 95% CI 1.64-22.05, respectively). CONCLUSION: Ferritin is a helpful biomarker for HLH diagnosis and prognostic prediction. Autoimmune disease-triggered HLH has favorable outcomes. Future prospective study is required to verify the use of the adapted HLH-2004 criteria.

Improving cytokine-induced killer cell expansion using a gas-permeable culture method for clinical-scale production.

BACKGROUND: Cytokine-induced killer (CIK) cells are a heterogeneous group of immune cells that exert potent MHC-unrestricted cytotoxicity toward various cancer cells in both solid and hematological malignancies. OBJECTIVE: The purposes of this study were to compare the expansion and characteristics of cytokine-induced killer cells between a standard culture method and a gas-permeable culture method and to develop a clinical-scale expansion protocol for cytokine-induced killer cells using a gas-permeable culture method. METHODS: We compared the absolute cell number, fold change, cell subsets, activation markers, cytokine concentrations, and cytotoxicity toward myeloid leukemia cell lines between cytokine-induced killer cells expanded using two different culture methods. Then, we determined the ability to achieve clinical-scale expansion of cytokine-induced killer cells using the gas-permeable culture method. RESULTS: Cytokine-induced killer cells in the gas-permeable culture method group exhibited significantly better expansion but maintained similar cell subsets, activation markers, and cytotoxicity to those in the standard culture method group. In addition, we successfully manufactured cytokine-induced killer cells for clinical use using the gas-permeable culture method. We also showed the clinical efficacy of allogeneic cytokine-induced killer cells produced by the gas-permeable culture method in a patient with acute myeloid leukemia that relapsed after allogeneic hematopoietic stem cell transplantation. This patient maintained ongoing disease remission for 2 years with minimal side effects after cytokine-induced killer cell infusion. CONCLUSIONS: We successfully developed a simple and effective protocol for the ex vivo expansion of cytokine-induced killer cells using the gas-permeable culture method for clinical application.

Expression of Programmed Cell Death-1 and Programmed Cell Death Ligands in Nodal Peripheral T-Cell Lymphoma: Expression Pattern and Potential Prognostic Relevance.

Programmed cell death (PD)/PD-ligands (PD-Ls) pathway plays an important role in the regulation of physiologic immune response. Several cancers, including lymphoma exhibit abnormal PD-1/PD-Ls expression, which may contribute to treatment failure, progression, and inferior outcomes. PD-1/PD-Ls expression has predominantly been described in B-cell lymphoma; such data in peripheral T-cell lymphoma (PTCL) is limited. We described PD-1/PD-Ls expression patterns and associations with clinical characteristics and outcomes, in patients with systemic PTCLs. Correlation between PD-1/PD-Ls expression and outcomes was analyzed in patients who received lymphoma-specific therapy. PD-1/PD-Ls expression was observed across all common PTCL histologies at different proportions (PD-1 0%-76.9%, PD-L1 38.5%-62.5%, and PD-L2 62.5%-100%) with PD-1 being highly expressed in angioimmunoblastic T-cell lymphoma. Baseline characteristics were comparable between PD-1/PD-Ls expression status. Of 47 patients who received lymphoma-specific therapy, outcomes were similar across all PD-L1/PD-L2 subgroups. In the Cox proportional hazard analysis, treatment response was the only factor associated with survival outcomes. However, PD-1/PD-Ls expression, either in lymphoma or stroma, was not a predictor for survival outcomes. In conclusion, differential PD-1/PD-Ls expressions were observed among various histological PTCL subtypes. In this study, we were unable to demonstrate an association between PD-1/PD-Ls expression, clinical characteristics, treatment response, and outcomes of PTCL patients.

Augmentation of NK Cell Proliferation and Anti-tumor Immunity by Transgenic Expression of Receptors for EPO or TPO.

Many investigational adoptive immunotherapy regimens utilizing natural killer (NK) cells require the administration of interleukin-2 (IL-2) or IL-15, but these cytokines cause serious dose-dependent toxicities. To reduce or preclude the necessity for IL-2 use, we investigated whether genetic engineering of NK cells to express the erythropoietin (EPO) receptor (EPOR) or thrombopoietin (TPO) receptor (c-MPL) could be used as a method to improve NK cell survival and function. Viral transduction of NK-92 cells to express EPOR or c-MPL receptors conveyed signaling via appropriate pathways, protected cells from apoptosis, augmented cellular proliferation, and increased cell cytotoxic function in response to EPO or TPO ligands in vitro. In the presence of TPO, viral transduction of primary human NK cells to express c-MPL enhanced cellular proliferation and increased degranulation and cytokine production toward target cells in vitro. In contrast, transgenic expression of EPOR did not augment the proliferation of primary NK cells. In immunodeficient mice receiving TPO, in vivo persistence of primary human NK cells genetically modified to express c-MPL was higher compared with control NK cells. These data support the concept that genetic manipulation of NK cells to express hematopoietic growth factor receptors could be used as a strategy to augment NK cell proliferation and antitumor immunity.

Causes and outcomes of hypereosinophilia in a tropical country.

BACKGROUND: Hypereosinophilia (HE), defined by blood eosinophils > 1.5 ? 109/L persisting over one month, is commonly found in clinical practice. OBJECTIVE: This study aimed to explore etiologies, clinical characteristics, and outcome of HE. METHODS: The HE patients from a single center in Thailand during 2014-2019 were retrospectively reviewed. RESULTS: Among 166 HE patients, 102 (61.5%) cases had reactive HE (HER) of which 52% was due to parasitic infestations. Two-thirds of these patients were diagnosed based on the patients' response to empirical anti-parasite therapy. Without secondary causes, eosinophil-related symptoms were found in 20 (12.0%) patients (Hypereosinophilic syndrome: HES) of which three of them had myeloid neoplasms (HESN) and one case had lymphocytic variant HES (L-HES). Among 11 of 16 idiopathic HES (HESI) patients who were treated with systemic steroid, nine (81.8%) patients responded well, and two cases obtained symptom improvement with stable eosinophilia. There was 44 (26.5%) asymptomatic HE of undetermined significance (HEUS) and 37 (84.1%) of them had HE for more than 6 months before diagnosis. Marked eosinophilia (> 10 ? 109/L) was more common in HES (37.5%), but it was also found in HER (16.7%) and HEUS (11.4%). During the median follow-up period of 16 months, 82.9% (34/41) of HEUS cases remained asymptomatic while seven (17.1%) patients spontaneously recovered. CONCLUSIONS: A therapeutic trial of anti-parasite is reasonable for asymptomatic HE in tropical countries. Most HESI responded to systemic corticosteroids and HEUS showed benign courses without therapy.

International, Multicenter Standardization of Acute Graft-versus-Host Disease Clinical Data Collection: A Report from the Mount Sinai Acute GVHD International Consortium.

Acute graft-versus-host disease (GVHD) remains a leading cause of morbidity and nonrelapse mortality after allogeneic hematopoietic cell transplantation. The clinical staging of GVHD varies greatly between transplant centers and is frequently not agreed on by independent reviewers. The lack of standardized approaches to handle common sources of discrepancy in GVHD grading likely contributes to why promising GVHD treatments reported from single centers have failed to show benefit in randomized multicenter clinical trials. We developed guidelines through international expert consensus opinion to standardize the diagnosis and clinical staging of GVHD for use in a large international GVHD research consortium. During the first year of use, the guidance followed discussion of complex clinical phenotypes by experienced transplant physicians and data managers. These guidelines increase the uniformity of GVHD symptom capture, which may improve the reproducibility of GVHD clinical trials after further prospective validation.

Combined peripheral blood monocyte count and white blood cell count as a guide for successful one-day autologous peripheral blood stem cell collection.

INTRODUCTION: Peripheral blood stem cells (PBSCs) are the most common source of stem cell transplantation, which depends on an adequate number of CD34+ cells. Although pre-apheresis CD34+ cell count is a standard guide for the collection, it is not always available. This study aimed to evaluate complete blood count parameters for predicting successful one-day autologous PBSC collection. METHODS: Data from the patients who underwent autologous PBSC collection at a tertiary care hospital were retrospectively reviewed. RESULTS: There were 123 patients (185 leukapheresis procedures). Successful PBSC collection (CD34+ cells ≥4.0 × 106 cells/kg) was obtained in 85 patients (69.1%), of which 55 (44.7%) were successfully obtained on the first day. The median CD34+ collection efficiency was 44.1%. The mean platelet loss during apheresis was 39.9%. The adverse event rate was 18.9%. Patients in whom PBSCs were collected within one day were less likely to experience adverse effects related to leukapheresis. Pre-apheresis CD34+ cells ≥10 cells/µLand combined white blood cell (WBC) counts ≥5 × 109/L and/or monocyte ≥10% were independently associated with the successful one-day PBSC collection (adjusted odds ratio 24.06, 95% confidence interval [CI] 5.30-109.10, p < 0.001; and 6.94, 95% CI 1.35-35.79, p = 0.021, respectively). Only pre-apheresis CD34+ cells had a strong correlation with the total stem cell yield. CONCLUSIONS: To reduce the complication of leukapheresis, the combined pre-apheresis WBC ≥5 × 109/L and/or monocyte ≥10% is a practical parameter to initiate a successfully one-day PBSC collection with or without pre-apheresis CD34+ cell results.

Optimization of anti-TIM3 chimeric antigen receptor with CD8α spacer and TNFR-based costimulation for enhanced efficacy in AML therapy.

CAR T cell therapy for AML remains limited due to the lack of a proper target without on-target off-tumor toxicity. TIM3 is a promising target due to its high expression on AML cells and absence in most normal hematopoietic cells. Previous reports have shown that each CAR component impacts CAR functionality. Here, we optimized TIM-3 targeting CAR T cells for AML therapy. We generated CARs targeting TIM3 with two different non-signaling domains: an IgG2-CH3 spacer with CD28 transmembrane domain (CH3/CD28) and a CD8α spacer with CD8α transmembrane domain (CD8/CD8), and evaluated their characteristics and function. Incorporating the non-signaling CH3/CD28 domain resulted in unstable CAR expression in anti-TIM3 CAR T cells, leading to lower surface CAR expression over time and reduced cytotoxic function compared to anti-TIM3 CARs with the CD8/CD8 domain. Both types of anti-TIM3 CAR T cells transiently exhibited fratricide, which subsided overtime, and both CAR T cells achieved substantial T cell expansion. To further optimize the design, we explored the effects of different costimulatory domains. Compared with CD28 costimulation, 4-1BB and CD27 combined with a CD8/CD8 non-signaling domain showed higher cytokine secretion, superior antitumor activity, and enhanced T-cell persistence after repeated antigen exposure. These findings emphasize the impact of the optimal design of CAR constructs that provide efficient function. In the context of anti-TIM3 CAR T cells, using a CD8α spacer and transmembrane domain with TNFR-based costimulation is a promising CAR design to improve anti-TIM3 CAR T cell function for AML therapy.

Flares of acute graft-versus-host disease: a Mount Sinai Acute GVHD International Consortium analysis.

ABSTRACT: The absence of a standardized definition for graft-versus-host disease (GVHD) flares and data on its clinical course are significant concerns. We retrospectively evaluated 968 patients across 23 Mount Sinai Acute GVHD International Consortium (MAGIC) transplant centers who achieved complete response (CR) or very good partial response (VGPR) within 4 weeks of treatment. The cumulative incidence of flares within 6 months was 22%, and flares were associated with a higher risk of nonrelapse mortality (NRM; adjusted hazard ratio [aHR], 4.84; 95% confidence interval [CI], 3.19-7.36; P < .001). Flares were more severe (grades 3/4, 41% vs 16%; P < .001) and had more frequent lower gastrointestinal (LGI) involvement (55% vs 32%; P < .001) than the initial GVHD. At CR/VGPR, elevated MAGIC biomarkers predicted the future occurrence of a flare, along with its severity and LGI involvement. In multivariate analyses, higher Ann Arbor (AA) biomarker scores at CR/VGPR were significant risk factors for flares (AA2 vs AA1: aHR, 1.81 [95% CI, 1.32-2.48; P = .001]; AA3 vs AA1: aHR, 3.14 [95% CI, 1.98-4.98; P < .001]), as were early response to initial treatment (aHR, 1.84; 95% CI, 1.21-2.80; P = .004) and HLA-mismatched unrelated donor (aHR, 1.74; 95% CI, 1.00-3.02; P = .049). MAGIC biomarkers also stratified the risk of NRM both at CR/VGPR and at the time of flare. We conclude that GVHD flares are common and carry a significant mortality risk. The occurrence of future flares can be predicted by serum biomarkers that may serve to guide adjustment and discontinuation of immunosuppression.

Amphiregulin, ST2, and REG3α biomarker risk algorithms as predictors of nonrelapse mortality in patients with acute GVHD.

ABSTRACT: Graft-versus-host disease (GVHD) is a major cause of nonrelapse mortality (NRM) after allogeneic hematopoietic cell transplantation. Algorithms containing either the gastrointestinal (GI) GVHD biomarker amphiregulin (AREG) or a combination of 2 GI GVHD biomarkers (suppressor of tumorigenicity-2 [ST2] + regenerating family member 3 alpha [REG3α]) when measured at GVHD diagnosis are validated predictors of NRM risk but have never been assessed in the same patients using identical statistical methods. We measured the serum concentrations of ST2, REG3α, and AREG by enzyme-linked immunosorbent assay at the time of GVHD diagnosis in 715 patients divided by the date of transplantation into training (2004-2015) and validation (2015-2017) cohorts. The training cohort (n = 341) was used to develop algorithms for predicting the probability of 12-month NRM that contained all possible combinations of 1 to 3 biomarkers and a threshold corresponding to the concordance probability was used to stratify patients for the risk of NRM. Algorithms were compared with each other based on several metrics, including the area under the receiver operating characteristics curve, proportion of patients correctly classified, sensitivity, and specificity using only the validation cohort (n = 374). All algorithms were strong discriminators of 12-month NRM, whether or not patients were systemically treated (n = 321). An algorithm containing only ST2 + REG3α had the highest area under the receiver operating characteristics curve (0.757), correctly classified the most patients (75%), and more accurately risk-stratified those who developed Minnesota standard-risk GVHD and for patients who received posttransplant cyclophosphamide-based prophylaxis. An algorithm containing only AREG more accurately risk-stratified patients with Minnesota high-risk GVHD. Combining ST2, REG3α, and AREG into a single algorithm did not improve performance.

Prognostic factors and impact of CMV reactivation on acute myeloid leukemia patients after HLA-matched myeloablative allogeneic stem cell transplantation in a high CMV prevalence country.

INTRODUCTION: Relapse of acute myeloid leukemia (AML) after allogeneic stem cell transplantation (allo-SCT) leads to dismal outcomes. This study aimed to identify high-risk patients and explore the effects of cytomegalovirus (CMV) reactivation in a high CMV-seropositive population. METHODS: The study involved a single-center retrospective cohort in Thailand, analyzing clinical risk factors and CMV-mediated immune responses, correlated with transplant outcomes in AML patients. RESULTS: Eighty-five patients with AML in complete remission (CR) undergoing HLA-matched myeloablative allo-SCT between 2011 and February 2021 were enrolled. The relapse rate was 27.1% with the median time of 7 months after transplantation. The 3-year relapse-free-survival (RFS) and overall-survival (OS) were 72.2% and 80.8%, respectively. The disease status (>CR1) and absence of chronic graft-versus-host disease (cGVHD) were independently significant adverse prognostic factors of RFS and OS. Ninety-two percent of recipient-donor pairs were both CMV seropositive. The CMV reactivation occurred in 54.1% of the patients. The clinically significant CMV infection rate was 49.4%. No CMV syndrome/disease or CMV-related mortality occurred. One-year cumulative incidence of relapse among CMV-reactivation and non-reactivation groups were 14.3% and 25.6%, respectively, without a statistically significant difference. Transplantation-related mortality was 11.1%. CONCLUSIONS: The transplantation beyond CR1 and absence of cGVHD are powerful prognostic factors associated with inferior RFS and OS. In a high CMV prevalence country, there appears to be no impact of CMV reactivation on relapse in AML patients undergoing an allo-SCT.

Does leukocytosis remain a predictive factor for survival outcomes in patients with acute promyelocytic leukemia receiving ATRA plus a chemotherapy-based regimen? A prospective multicenter analysis from TALWG.

INTRODUCTION: Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia (AML) with a unique clinical presentation and prognosis. This study aimed to investigate the epidemiology, clinical characteristics, treatments, and clinical outcomes of Thai APL patients dominantly treated with all-trans-retinoic acid (ATRA) combined with a chemotherapy-based therapy. METHODS: This was an eight-year prospective, observational study from nine academic hospitals in the Thai Acute Leukemia Working Group (TALWG) of the Thai Society of Hematology, which included newly diagnosed Thai APL patients, aged 18 years or older. The web-based registration collected baseline charateristic, and clinical outcomes. RESULTS: From 992 newly diagnosed AML patients, 79 APL patients were enrolled in this study. Almost all subjects were de novo APL (94.9%), while the others were therapy-related APL. The commonest clinical presentation was disseminated intravascular coagulation (38%). One-third of the patients were categorized as high risk according to the initial WBC. Almost all patients received ATRA combined with idarubicin regimen. The complete response rate was as high as 95.7%, which translated into excellent four-year overall survival (OS) (75.6%) and four-year leukemia-free survival (LFS) (75.4%). The multivariate analysis demonstrated that the older age and WBC count >20 × 109/L conferred a significantly unfavorable OS with the hazard ratios of 3.03 (95% confidence interval [CI]: 1.14-8.05) and 4.18 (95%CI: 1.69-10.35), respectively. Similarly, these two parameters remained independent of the poor prognosis factors for LFS. CONCLUSION: This report confirmed that APL had a favorable prognosis. However, advanced age and high WBC count >20 × 109/L contributed to a worse outcome. ABBREVIATIONS: APL; acute promyelocytic leukemia; ATRA; all-transretinoic acid; CR; complete remission; DS; differentiation syndrome; ECOG; Eastern Cooperative Oncology Group; ED; early death; HR; hazard ratio; IQR; interquartile range; LFS; leukemia-free survival; OS; overall survival; WBC; white blood cell.

Incidence, clinical presentation, risk factors, outcomes, and biomarkers in de novo late acute GVHD.

Late acute graft-versus-host disease (GVHD) is defined as de novo acute GVHD presenting beyond 100 days after allogeneic hematopoietic cell transplantation (HCT) without manifestations of chronic GVHD. Data are limited regarding its characteristics, clinical course, and risk factors because of underrecognition and changes in classification. We evaluated 3542 consecutive adult recipients of first HCTs at 24 Mount Sinai Acute GVHD International Consortium (MAGIC) centers between January 2014 and August 2021 to better describe the clinical evolution and outcomes of late acute GVHD. The cumulative incidence of classic acute GVHD that required systemic treatment was 35.2%, and an additional 5.7% of patients required treatment for late acute GVHD. At the onset of symptoms, late acute GVHD was more severe than classic acute GVHD based on both clinical and MAGIC algorithm probability biomarker parameters and showed a lower overall response rate on day 28. Both clinical and biomarker grading at the time of treatment stratified the risk of nonrelapse mortality (NRM) in patients with classic and late acute GVHD, respectively, but long-term NRM and overall survival did not differ between patients with classic and late acute GVHD. Advanced age, female-to-male sex mismatch, and the use of reduced intensity conditioning were associated with the development of late acute GVHD, whereas the use of posttransplant cyclophosphamide-based GVHD prevention was protective mainly because of shifts in GVHD timing. Because overall outcomes were comparable, our findings, although not definitive, suggest that similar treatment strategies, including eligibility for clinical trials, based solely on clinical presentation at onset are appropriate.

Phase 2 study of natalizumab plus standard corticosteroid treatment for high-risk acute graft-versus-host disease.

Graft-versus-host disease (GVHD) of the gastrointestinal (GI) tract is the main cause of nonrelapse mortality (NRM) after allogeneic hematopoietic cell transplantation. Ann Arbor (AA) scores derived from serum biomarkers at onset of GVHD quantify GI crypt damage; AA2/3 scores correlate with resistance to treatment and higher NRM. We conducted a multicenter, phase 2 study using natalizumab, a humanized monoclonal antibody that blocks T-cell trafficking to the GI tract through the α4 subunit of α4ß7 integrin, combined with corticosteroids as primary treatment for patients with new onset AA2/3 GVHD. Seventy-five patients who were evaluable were enrolled and treated; 81% received natalizumab within 2 days of starting corticosteroids. Therapy was well tolerated with no treatment emergent adverse events in >10% of patients. Outcomes for patients treated with natalizumab plus corticosteroids were compared with 150 well-matched controls from the MAGIC database whose primary treatment was corticosteroids alone. There were no significant differences in overall or complete response between patients treated with natalizumab plus corticosteroids and those treated with corticosteroids alone (60% vs 58%; P = .67% and 48% vs 48%; P = 1.0, respectively) including relevant subgroups. There were also no significant differences in NRM or overall survival at 12 months in patients treated with natalizumab plus corticosteroids compared with controls treated with corticosteroids alone (38% vs 39%; P = .80% and 46% vs 54%; P = .48, respectively). In this multicenter biomarker-based phase 2 study, natalizumab combined with corticosteroids failed to improve outcome of patients with newly diagnosed high-risk GVHD. This trial was registered at www.clinicaltrials.gov as # NCT02133924.

Characteristics and clinical correlation of TIM-3 and PD-1/PD-L1 expressions in leukemic cells and tumor microenvironment in newly diagnosed acute myeloid leukemia.

Dual targeting of TIM-3 and PD-1/PD-L1 pathways is currently under investigation for cancer immunotherapy. The interaction of these immune checkpoints remains unclear in the leukemic microenvironment of acute myeloid leukemia (AML). We performed an immunophenotypic study of bone marrow in 37 newly diagnosed AML patients. High levels of TIM-3 expression on AML blasts were correlated with first 7 + 3 induction failure (CR 16.2% vs. non-CR 36.4%, p = .038). In contrast, high TIM-3 levels on natural killer (NK) cells were associated with complete remission (CR) status after induction (CR 24.7% vs. non-CR 6.5%, p = .035). Few PD-L1 positive AML blasts and PD-1 or PD-L1 positive NK cells were observed. Although the exhausted PD-1 expressing T cells were detected in 28.3% of T cells, the double positive of PD-1 and TIM-3 T cells were rarely detected. In summary, the TIM-3 levels on AML blasts and NK cells are potentially the prognostic biomarkers in AML.

Excellent Prognosis of Low-Risk Myelodysplastic Syndromes (MDS) Without Detectable Myeloid-Related Mutations.

BACKGROUND: Unexplained cytopenia (UC) and low-risk myelodysplastic syndrome (MDS) are distinguished mainly by morphologic dysplasia, which sometimes shows inter-observer discrepancy. We hypothesized that gene mutations are strong prognostic factors for these low-risk patients. MATERIALS AND METHODS: We enrolled patients from 4 medical centers with unexplained cytopenia of at least 1 lineage. Diagnosis of low-risk MDS was made according to WHO 2016 classification and a revised international prognostic scoring system (R-IPSS) score of ≤ 3.5. DNA was extracted from bone marrow or blood and sequenced by targeted next generation sequencing (NGS). RESULTS: One hundred twenty-one patients were recruited: 25% with UC and 75% with low-risk MDS. Complete blood counts were similar, but low-risk MDS patients carried higher numbers of mutations (1 vs. 0; P = .04) than UC patients. Overall, the most frequent mutated genes were TET2 (14.6%), SF3B1 (12.2%), and ASXL1 (9.7%). Survival rates of low-risk MDS patients versus UC patients were not significantly different. UC patients and low-risk MDS patients without genetic abnormalities showed superior 5-year progression free survival compared to MDS patients with mutations (100% vs. 76.0%; P = .005). Overall, ASXL1 mutations were associated with decreased 4-year overall survival compared to wild-type (59% vs. 31%; P = .01). In a multivariate analysis, ASXL1 and DNMT3A mutations in low-risk MDS patients were associated with a higher risk of disease progression with hazard ratios of 7.88 (95% CI 1.76-35.32, P = .01) and 7.45 (95% CI 1.61-34.46, P = .01), respectively. CONCLUSION: Mutation detection is important for proper risk stratification of patients presenting with idiopathic cytopenia.

Ablation of VLA4 in multiple myeloma cells redirects tumor spread and prolongs survival.

Multiple myeloma (MM) is a cancer of bone marrow (BM) plasma cells, which is increasingly treatable but still incurable. In 90% of MM patients, severe osteolysis results from pathological interactions between MM cells and the bone microenvironment. Delineating specific molecules and pathways for their role in cancer supportive interactions in the BM is vital for developing new therapies. Very Late Antigen 4 (VLA4, integrin α4ß1) is a key player in cell-cell adhesion and signaling between MM and BM cells. We evaluated a VLA4 selective near infrared fluorescent probe, LLP2A-Cy5, for in vitro and in vivo optical imaging of VLA4. Furthermore, two VLA4-null murine 5TGM1 MM cell (KO) clones were generated by CRISPR/Cas9 knockout of the Itga4 (α4) subunit, which induced significant alterations in the transcriptome. In contrast to the VLA4+ 5TGM1 parental cells, C57Bl/KaLwRij immunocompetent syngeneic mice inoculated with the VLA4-null clones showed prolonged survival, reduced medullary disease, and increased extramedullary disease burden. The KO tumor foci showed significantly reduced uptake of LLP2A-Cy5, confirming in vivo specificity of this imaging agent. This work provides new insights into the pathogenic role of VLA4 in MM, and evaluates an optical tool to measure its expression in preclinical models.

Comparison of Three Doses of Cytarabine Consolidation for Intermediate- and Adverse-risk Acute Myeloid Leukemia: Real World Evidence From Thai Acute Myeloid Leukemia Registry.

BACKGROUND: Intermediate or high doses of cytarabine (IDAC or HiDAC) were recommended as postremission chemotherapy for acute myeloid leukemia (AML). This retrospective study investigated the real-world outcomes of 3-different cytarabine doses from the multicenter Thai AML registry database. PATIENTS AND METHODS: The intermediate- and adverse-risk AML patients (N = 258) who achieved complete remission and proceeded to single-agent cytarabine consolidation were enrolled. RESULTS: The median relapse-free survival (RFS) using IDAC 1.5 g/m2, high-dose cytarabine (HiDAC) 2 g/m2, and HiDAC 3 g/m2 were 12.6, 11.7, and 13 months, respectively. The median overall survival (OS) using IDAC 1.5 g/m2, HiDAC 2 g/m2, and HiDAC 3 g/m2 were 34.9, 22.7, and 23.7 months, respectively. No significant difference in RFS and OS was detected between the 3 doses. Secondary AML, white blood cell > 100×109/L and the adverse-risk AML were independent prognostic factors for inferior survival (P= .008, P < .001, P= .014). Patients who completed 3 to 4 cycles of consolidation had significantly superior RFS and OS (P< .001, P< .001). Febrile neutropenia occurred in 72.9% of IDAC, 73.8% of HiDAC 2 g/m2, and 78.1% of HiDAC 3 g/m2 without statistical significance. However, the incidence of septic shock was significantly higher after HiDAC 3 g/m2 compared to IDAC regimen (8% vs. 3%, P= .037). CONCLUSION: IDAC is an appropriate regimen for postremission chemotherapy for intermediate- and adverse-risk AML. The higher dosing levels may not produce any benefits to patients and may increase incidence of septic shock. The number of consolidation cycles may impact on survivals rather than the intensity of cytarabine.