Chimeric antigen receptor T-cell infusion for large B-cell lymphoma in complete remission: a center for international blood and marrow transplant research analysis.

CD19 CAR T-cell (CAR-T) therapy is commonly administered to patients with relapsed or refractory large B-cell lymphomas (LBCL), but salvage or bridging therapy can sometimes lead to a complete response (CR) prior to infusion. Limited studies have assessed the outcomes of patients infused in CR. A total of 134 patients with LBCL in CR prior to CAR-T infusion were identified from the CIBMTR registry, with median prior lines of therapy of 3 (range 2-9). At two years post-infusion, the probability of progression-free survival was 43.5% (95% CI 34.4-52.8) and the probability of overall survival was 63.8% (95% CI 54.4-72.6). The cumulative incidence rates of non-relapse mortality and relapse/progression at two years were 9.2% (95% CI 4.5-15.4) and 47.3% (95% CI 38.2-56.6), respectively. The rate of grade 3 or higher cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) were 2.2% and 8.2%, respectively. In summary, CAR-T in heavily pretreated patients with LBCL who are in CR following two or more lines of prior therapy demonstrate that a subset of patients may remain free of progression at two years. Additionally, the toxicity profile was impressive with very low rates of grade 3 CRS and ICANS.

Improving Unrelated Donor Equity: Assessing Mismatched Donor Opportunities with Real-World Data in a Minority-Predominant Cohort.

Recent advances in graft-versus-host disease (GVHD) prophylaxis including post-transplant cyclophosphamide (PTCy) and abatacept have significantly improved outcomes following HLA-mismatched allogenic hematopoietic stem cell transplantation (allo-HSCT) and have tremendous potential for reducing racial disparities in donor availability. A recent small study employing bone marrow as the source of stem cells showed similar outcomes after 5/8 versus 7/8 matches and is currently being tested in a larger study using peripheral blood stem cells. In this study, we examine real-world alternative donor HSCT options for a minority-predominant cohort in the Bronx, NY, focusing on the availability of lesser-matched (5/8 to 7/8) donors. Records of patients who underwent HLA typing at Montefiore Medical Center (2019 to 2022) were reviewed. The National Marrow Donor Program registry was queried to evaluate the availability of donors with at least 99% likelihood of HLA match at various levels (5/8, 6/8, 7/8, 8/8). Two hundred forty-one patients were included, 70% were non-White. Although the availability of ≥7/8 donors was less common in non-White patients, 100% of patients from each group had at least one or more 5/8 and 6/8 HLA-matched donors and more than 80% of these patients had >100 potential 5/8 and 6/8 HLA-matched donors. There was no statistical difference by race or ethnicity in the mean number of donors at 5/8 and 6/8 HLA-match levels. We demonstrate through real-world data that patients from diverse ethnic and racial backgrounds have access to 5/8 and 6/8 HLA-matched donors for allo-HSCT, potentially eliminating disparities in donor availability and allowing prioritization of other donor selection characteristics such as donor age, sex, ABO, and B leader matching. Further work is needed to study whether the use of mismatched donors offers a more potent graft-versus malignancy effect and optimal GVHD prophylaxis.

Immunotherapy-resistant acute lymphoblastic leukemia cells exhibit reduced CD19 and CD22 expression and BTK pathway dependency.

While therapies targeting CD19 by antibodies, chimeric antigen receptor T cells (CAR-T), and T cell engagers have improved the response rates in B cell malignancies, the emergence of resistant cell populations with low CD19 expression can lead to relapsed disease. We developed an in vitro model of adaptive resistance facilitated by chronic exposure of leukemia cells to a CD19 immunotoxin. Single-cell RNA-Seq (scRNA-Seq) showed an increase in transcriptionally distinct CD19lo populations among resistant cells. Mass cytometry demonstrated that CD22 was also decreased in these CD19lo-resistant cells. An assay for transposase-accessible chromatin with sequencing (ATAC-Seq) showed decreased chromatin accessibility at promoters of both CD19 and CD22 in the resistant cell populations. Combined loss of both CD19 and CD22 antigens was validated in samples from pediatric and young adult patients with B cell acute lymphoblastic leukemia (B-ALL) that relapsed after CD19 CAR-T-targeted therapy. Functionally, resistant cells were characterized by slower growth and lower basal levels of MEK activation. CD19lo resistant cells exhibited preserved B cell receptor signaling and were more sensitive to both Bruton's tyrosine kinase (BTK) and MEK inhibition. These data demonstrate that resistance to CD19 immunotherapies can result in decreased expression of both CD19 and CD22 and can result in dependency on BTK pathways.

TMIGD2 is an orchestrator and therapeutic target on human acute myeloid leukemia stem cells.

Acute myeloid leukemia (AML) is initiated and sustained by a hierarchy of leukemia stem cells (LSCs), and elimination of this cell population is required for curative therapies. Here we show that transmembrane and immunoglobulin domain containing 2 (TMIGD2), a recently discovered co-stimulatory immune receptor, is aberrantly expressed by human AML cells, and can be used to identify and enrich functional LSCs. We demonstrate that TMIGD2 is required for the development and maintenance of AML and self-renewal of LSCs but is not essential for normal hematopoiesis. Mechanistically, TMIGD2 promotes proliferation, blocks myeloid differentiation and increases cell-cycle of AML cells via an ERK1/2-p90RSK-CREB signaling axis. Targeting TMIGD2 signaling with anti-TMIGD2 monoclonal antibodies attenuates LSC self-renewal and reduces leukemia burden in AML patient-derived xenograft models but has negligible effect on normal hematopoietic stem/progenitor cells. Thus, our studies reveal the function of TMIGD2 in LSCs and provide a promising therapeutic strategy for AML.

Clinicopathologic characterization of cutaneous adult T-cell leukemia/lymphoma: A single tertiary care center experience in the United States.

OBJECTIVES: Adult T-cell leukemia/lymphoma (ATLL) is a rare aggressive T-cell leukemia/lymphoma associated with human T lymphotropic virus type 1 infection. The patients might present with skin rash before, at, or after the diagnosis. The dermatopathologic finding might be diagnostically very challenging. METHODS: We retrospectively identified 110 patients with ATLL at a single institution in a 19-year period, with 19 patients having skin biopsies. Clinical, dermatopathologic, immunophenotypic, and molecular findings were studied. RESULTS: The cohort included 13 skin-first (5 acute, 5 lymphomatous, 2 chronic, 1 smoldering), 6 skin-second (4 acute, 1 lymphomatous, 1 smoldering), and 91 patients without skin biopsy. Some nonphotoprotected areas of body such as the forearm and lower lip were also seen. Skin manifestations included papular (5), erythroderma (1), nodulotumoral (3), plaques (1), patches (1), and a combination of skin rashes (2). Histopathologic findings included large pleomorphic cells, angiocentrism, epidermal infiltration with large Pautrier-like microabscesses, and folliculotropism. Fifteen (78.9%) cases showed CD4+/CD7-/CD25+. Next-generation sequencing study was conducted on 5 patients using either blood or bone marrow samples, revealing multiple genetic mutations across multiple signaling pathways. CONCLUSIONS: Pleomorphic large, atypical cells with CD4+/CD25+/CD7- immunophenotype from a non-"bathing trunk" location, especially in a patient from endemic regions, raise suspicion for ATLL. T-cell receptor gene rearrangement is almost always positive, and the neoplasm usually demonstrates multiple mutations by next-generation sequencing study.

Impact of race and ethnicity on early mortality in multiple myeloma: a SEER analysis.

Over the past two decades, there have been significant advances in the treatment of multiple myeloma which has led to an improvement in overall survival (OS) (1,2). However, a notable proportion of patients continue to experience early mortality (EM), defined as two years from the time of diagnosis. This raises the possibility that improvements in myeloma survival have not extended equally to all groups. Using the latest data drawn from the Surveillance Epidemiology and End Results (SEER) database of patients in the United States spanning 2000-2019, we study impact of important sociodemographic factors on EM. Through regression modeling, we demonstrate that patients diagnosed from 2000-2005, of older age, male sex, and of certain racial minority status (non-Hispanic Black and Hispanic) have higher odds of EM. Of these factors, minority status contributed to worse 2-year overall survival as well. We evaluate whether income, as a surrogate to access to care, could potentially explain this finding, but find that race has a distinct relationship with EM that is not modified by income. This is further reinforced by subgroup analysis. After characterizing groups vulnerable to EM, we examine reasons for these disparities and potential avenues to address them.

Acute myeloid leukemias with JAK2/STAT mutations are associated with PD-L1 upregulation.

Even though overexpression of the immune checkpoint protein, programmed cell death ligand-1 (PD-L1), is observed in solid tumors, its expression patterns in acute myeloid leukemia remain understudied. As activation of the JAK/STAT pathway has been shown to enhance PD-L1 expression in preclinical models, we evaluated biopsies from AML patients with activating mutations in JAK2/STATs. PD-L1 expression was significantly upregulated in JAK2/STAT mutant cases when compared to JAK2 wildtype controls as demonstrated by PD-L1 immunohistochemistry staining and quantified using the combined positive score (CPS) system. There is significant overexpression of phosphorylated STAT3 expression in patients with oncogenic JAK2 activation and a positive correlation between p-STAT3 and PD-L1 expression. In conclusion, we demonstrate the CPS scoring system could be applied as a quantitative measure of PD-L1 expression in leukemias and that JAK2/STATs mutant AML can be potential candidates for checkpoint inhibitor trials.

A Metabolically Optimized, Noncytotoxic Low-Dose Weekly Decitabine/Venetoclax in MDS and AML.

PURPOSE: Venetoclax (VEN) added to the hypomethylating agents (HMA) decitabine or azacitidine is the new standard of care for elderly patients with acute myeloid leukemia (AML) and is being evaluated in myelodysplastic syndrome (MDS). Current dosing of HMA/VEN relies on leukemia suppression through cytotoxicity which also impacts normal hematopoiesis. A regimen using once-weekly low-dose decitabine (LDDec) has demonstrated activity in myeloid malignancies. To overcome the severe myelosuppression often seen with HMA/VEN, we evaluated a once-weekly dosing regimen of VEN and LDDec in elderly and/or frail patients who were felt less likely to tolerate severe myelosuppression. PATIENTS AND METHODS: This is a retrospective, single-center analysis of patients with AML, MDS, or chronic myelomonocytic leukemia treated with a once-weekly LDDec/VEN regimen. We also compare this regimen with a cohort treated with standard dosing HMA/VEN. RESULTS: In a retrospective cohort of 39 patients, the overall response rate for patients receiving LDDec/VEN for first-line AML and MDS was 88% and 64%, respectively. In patients with TP53 mutations, the composite complete response rate was 71% and the median overall survival was 10.7 months. When compared with 36 patients receiving standard dose HMA/VEN, the LDDec/VEN patients had a longer time on therapy (175 vs. 78 days; P = 0.014) and a trend toward a higher rate of transfusion independence (47% vs. 26%; P = 0.33). Neutropenic fever occurred in 31% of patients, with a median of one hospitalization at any point during treatment. CONCLUSIONS: This preliminary clinical experience, although retrospective, provides proof-of-activity of noncytotoxic DNA methyltransferase 1-targeting by allowing frequent, sustained drug exposure often not possible with standard HMA/VEN regimens.

Lenalidomide and Eltrombopag for Treatment of Low- or Intermediate-Risk Myelodysplastic Syndrome: Result of a Phase II Clinical Trial.

PURPOSE: Thrombocytopenia is a serious complication of myelodysplastic syndromes (MDS) associated with an increased bleeding risk and worse prognosis. Eltrombopag (ELT), a thrombopoietin receptor agonist, can increase platelet counts and reverse anti-megakaryopoietic effects of lenalidomide (LEN) in preclinical studies. We hypothesized ELT would reduce the incidence of thrombocytopenia in MDS. PATIENTS AND METHODS: We conducted a Phase II multicenter trial of ELT and LEN in adult patients with low- or intermediate-1-risk MDS with symptomatic or transfusion-dependent anemia or thrombocytopenia (NCT01772420). Thrombocytopenic patients were started on ELT and subsequently treated with LEN after platelets were increased. Patients without thrombocytopenia were started on LEN monotherapy and treated with ELT if they became thrombocytopenic. RESULTS: Fifty-two patients were enrolled; mean age was 71 years (range 34-93). Overall response rate (ORR) in the intention-to-treat population was 35% (18/52). ELT monotherapy led to ORR of 33.3% (7/21), 29% achieving hematologic improvement (HI)-Platelets, and 24% bilineage responses. LEN monotherapy had 38% ORR (6/16) with all responders achieving HI-Erythroid. Fifteen patients received both ELT and LEN with ORR of 33.3%, 20% achieved HI-Erythroid, and 20% HI-Platelets with 13% bilineage responses. Median duration of response was 40 weeks for ELT (range 8-ongoing), 41 weeks (25-ongoing) for LEN, and 88 weeks (8.3-ongoing) for ELT/LEN. Non-hematologic grade 3-4 treatment-related adverse events were infrequent. Among patients on ELT, 2 had major bleeding events, 1 had a reversible increase in peripheral blasts, and 1 developed marrow fibrosis after 6 years on ELT. CONCLUSIONS: ELT and LEN are well tolerated and effective in achieving hematologic improvement in patients with low-/intermediate-risk MDS.

Patients Recently Treated for B-lymphoid Malignancies Show Increased Risk of Severe COVID-19.

Patients with B-lymphoid malignancies have been consistently identified as a population at high risk of severe COVID-19. Whether this is exclusively due to cancer-related deficits in humoral and cellular immunity, or whether risk of severe COVID-19 is increased by anticancer therapy, is uncertain. Using data derived from the COVID-19 and Cancer Consortium (CCC19), we show that patients treated for B-lymphoid malignancies have an increased risk of severe COVID-19 compared with control populations of patients with non-B-lymphoid malignancies. Among patients with B-lymphoid malignancies, those who received anticancer therapy within 12 months of COVID-19 diagnosis experienced increased COVID-19 severity compared with patients with non-recently treated B-lymphoid malignancies, after adjustment for cancer status and several other prognostic factors. Our findings suggest that patients recently treated for a B-lymphoid malignancy are at uniquely high risk for severe COVID-19. SIGNIFICANCE: Our study suggests that recent therapy for a B-lymphoid malignancy is an independent risk factor for COVID-19 severity. These findings provide rationale to develop mitigation strategies targeted at the uniquely high-risk population of patients with recently treated B-lymphoid malignancies. This article is highlighted in the In This Issue feature, p. 171.

COVID-19 in Patients with Hematologic Malignancies: Outcomes and Options for Treatments.

Patients with hematologic malignancies are particularly vulnerable to infections due to underlying humoral and cellular immune dysfunction, cytotoxic chemotherapy regimens, advanced age, and the presence of comorbid conditions. Infection from severe acute respiratory syndrome coronavirus 2, the causative agent of the COVID-19 pandemic, has become a leading cause of death globally and has disproportionally affected this high-risk population. Here, we review the cumulative evidence demonstrating worse outcomes for patients with hematologic malignancies when compared to patients with solid tumors and the general population. We examine risk factors shared with the general population (age, sex, comorbid conditions, and race) and those that are cancer-specific (cytotoxic chemotherapy, progressive disease, and cancer type), all of which confer an increased risk of severe COVID-19. Despite the historical exclusion of cancer patients from COVID-19 therapy trials, we review the emerging evidence that patients with hematologic malignancies benefit from specific treatments such as convalescent plasma. Although COVID-19 vaccines are significantly less effective in this patient population, encouraging results are observed in a subset of these patients after receiving a booster dose.

Whole-genome landscape of adult T-cell leukemia/lymphoma.

Adult T-cell leukemia/lymphoma (ATL) is an aggressive neoplasm immunophenotypically resembling regulatory T cells, associated with human T-cell leukemia virus type-1. Here, we performed whole-genome sequencing (WGS) of 150 ATL cases to reveal the overarching landscape of genetic alterations in ATL. We discovered frequent (33%) loss-of-function alterations preferentially targeting the CIC long isoform, which were overlooked by previous exome-centric studies of various cancer types. Long but not short isoform-specific inactivation of Cic selectively increased CD4+CD25+Foxp3+ T cells in vivo. We also found recurrent (13%) 3'-truncations of REL, which induce transcriptional upregulation and generate gain-of-function proteins. More importantly, REL truncations are also common in diffuse large B-cell lymphoma, especially in germinal center B-cell-like subtype (12%). In the non-coding genome, we identified recurrent mutations in regulatory elements, particularly splice sites, of several driver genes. In addition, we characterized the different mutational processes operative in clustered hypermutation sites within and outside immunoglobulin/T-cell receptor genes and identified the mutational enrichment at the binding sites of host and viral transcription factors, suggesting their activities in ATL. By combining the analyses for coding and noncoding mutations, structural variations, and copy number alterations, we discovered 56 recurrently altered driver genes, including 11 novel ones. Finally, ATL cases were classified into 2 molecular groups with distinct clinical and genetic characteristics based on the driver alteration profile. Our findings not only help to improve diagnostic and therapeutic strategies in ATL, but also provide insights into T-cell biology and have implications for genome-wide cancer driver discovery.

Efficacy of booster doses in augmenting waning immune responses to COVID-19 vaccine in patients with cancer.

Anti-COVID-19 immunity dynamics were assessed in patients with cancer in a prospective clinical trial. Waning of immunity was detected 4-6 months post-vaccination with significant increases in anti-spike IgG titers after booster dosing, and 56% of seronegative patients seroconverted post-booster vaccination. Prior anti-CD20/BTK inhibitor therapy was associated with reduced vaccine efficacy.

Elevated LDH greater than 400 U/L portends poorer overall survival in diffuse large B-cell lymphoma patients treated with CD19 CAR-T cell therapy in a real world multi-ethnic cohort.

Anti-CD19 chimeric antigen receptor T-cell therapies have shown striking clinical activity in diffuse large B-cell lymphoma but robust biomarkers predictive of responsiveness are still needed. We treated a multi-ethnic cohort of 31 diffuse large B-cell lymphoma patients with axicabtagene ciloleucel with an overall response rate of 71%. Analysis of various biomarkers identified a significant decrease in overall survival with elevated lactate dehydrogenase, measured both at time of cell infusion and before lymphodepletion. Lactate dehydrogenase was prognostic in a multivariate analysis [HR = 1.47 (1.1-2.0)] and a value of 400 U/L at time of infusion and a value of 440 U/L before lymphodepletion provided the best prognostic cutoffs for overall survival in our cohort. These data demonstrate efficacy of anti-CD19 chimeric antigen receptor T-cell therapy in a diverse inner city population and demonstrate novel lactate dehydrogenase cutoffs as prognostic biomarkers.

Patterns of leukocyte recovery predict infectious complications after CD19 CAR-T cell therapy in a real-world setting.

BACKGROUND: Adoptive immunotherapy using CD19-targeted Chimeric antigen receptor T cells (CAR-T) has revolutionized the treatment of relapsed/refractory diffuse large B-cell lymphoma (DLBCL). Data is limited on the propensity of infections and lymphohematopoietic reconstitution after Day 30 (D30) following CAR-T cell therapy. In this study, we evaluated the prevalence and nature of infectious complications in an expanded cohort of DLBCL patients treated with CD19 CAR-T therapy and its association with the dynamics of leukocyte subpopulation reconstitution post-CAR-T cell therapy. METHODS: We conducted a retrospective study including 19 patients who received axicabtagene ciloleucel and investigated associations between cytopenia and infectious complications after D30. RESULTS: Nineteen patients were included, consisting of 42% Hispanic, 32% Caucasian, 21% African-American, and 5% Asian subjects. Post-D30 of CAR-T infusion, 47% patients (n=9) developed an infection and 53% (n=10) remained infection-free. The most common infection type observed was viral (7 patients) followed by bacterial (5 patients) and fungal (3 patients). Of 25 total infectious events, 56% were grade 1 or 2 and 44% were grade 3 with 10 being viral in etiology. To determine the kinetics of lymphohematopoietic reconstitution and its association with infection risk, we evaluated the relationship between cytopenias and rates of infection after D30. Notably, compared to non-infection group, infection group had a higher median absolute lymphocyte count (ALC) (1,000/µL vs. 600/µL, P<0.05), a lower median absolute neutrophil count (ANC)/ALC ratio (1.6 vs. 3.1, P<0.05) and a lower median AMC/ALC at D30 (0.37 vs. 1.67, P<0.05). In addition, we observed that only 22% of patients had recovered ANC >1,500/µL in the infection group as opposed to 70% in the non-infection group at D90 (P<0.05). Fifty-eight percent of the patients (11/19) with relapsed refractory DLBCL achieved a complete response with a median follow-up of 233 days (7.7 months). CONCLUSIONS: Although CAR-T cell therapy is highly effective, infectious complications remain an important cause of morbidity and mortality. Low ANC/ALC and AMC/ALC ratios at D30 are potential novel predictors of infection and can be considered in future prophylactic strategies.