Background Patients with hematological malignancies (HM) are at high risk of mortality from SARS-CoV-2 disease 2019 (COVID-19). A better understanding of risk factors for adverse outcomes may improve clinical management in these patients. We therefore studied baseline characteristics of HM patients developing COVID-19 and analyzed predictors of mortality. Methods The survey was supported by the Scientific Working Group Infection in Hematology of the European Hematology Association (EHA). Eligible for the analysis were adult patients with HM and laboratory-confirmed COVID-19 observed between March and December 2020. Results The study sample includes 3801 cases, represented by lymphoproliferative (mainly non-Hodgkin lymphoma n = 1084, myeloma n = 684 and chronic lymphoid leukemia n = 474) and myeloproliferative malignancies (mainly acute myeloid leukemia n = 497 and myelodysplastic syndromes n = 279). Severe/critical COVID-19 was observed in 63.8% of patients (n = 2425). Overall, 2778 (73.1%) of the patients were hospitalized, 689 (18.1%) of whom were admitted to intensive care units (ICUs). Overall, 1185 patients (31.2%) died. The primary cause of death was COVID-19 in 688 patients (58.1%), HM in 173 patients (14.6%), and a combination of both COVID-19 and progressing HM in 155 patients (13.1%). Highest mortality was observed in acute myeloid leukemia (199/497, 40%) and myelodysplastic syndromes (118/279, 42.3%). The mortality rate significantly decreased between the first COVID-19 wave (March–May 2020) and the second wave (October–December 2020) (581/1427, 40.7% vs. 439/1773, 24.8%, p value < 0.0001). In the multivariable analysis, age, active malignancy, chronic cardiac disease, liver disease, renal impairment, smoking history, and ICU stay correlated with mortality. Acute myeloid leukemia was a higher mortality risk than lymphoproliferative diseases. Conclusions This survey confirms that COVID-19 patients with HM are at high risk of lethal complications. However, improved COVID-19 prevention has reduced mortality despite an increase in the number of reported cases.

Our study suggests that using specific qPCR targeting several species of Mucorales according to local ecology to screen at-risk patients could be useful in a clinical setting. The cost and efficacy of this strategy should be evaluated. However, given the human and economic cost of mucormycosis and the need for rapid diagnosis to initiate prompt directed antifungal therapy, this strategy could be highly attractive.

Prolonged Covid‐19 is an emerging issue for patients with lymphoma or immune deficiency. We aimed to examine prolonged length of in‐hospital stay (LOS) due to Covid‐19 among patients with lymphoma and assess its determinants and outcomes. Adult patients with lymphoma admitted for Covid‐19 to 16 French hospitals in March and April, 2020 were included. Length of in‐hospital stay was analyzed as a competitor vs death. The study included 111 patients. The median age was 65 years (range, 19–92). Ninety‐four patients (85%) had B‐cell non‐Hodgkin lymphoma. Within the 12 months prior to hospitalization for Covid‐19, 79 patients (71%) were treated for their lymphoma. Among them, 63 (57%) received an anti‐CD20 therapy. Fourteen patients (12%) had relapsed/refractory disease. The median LOS was 14 days (range, 1–235). After a median follow‐up of 191 days (3–260), the 6‐month overall survival was 69%. In multivariable analyses, recent administration of anti‐CD20 therapy was associated with prolonged LOS (subdistribution hazard ratio 2.26, 95% confidence interval 1.42–3.6, p < 0.001) and higher risk of death (hazard ratio 2.17, 95% confidence interval 1.04–4.52, p = 0.039). An age ≥ 70 years and relapsed/refractory lymphoma were also associated with prolonged LOS and decreased overall survival. In conclusion, an age ≥ 70 years, a relapsed/refractory lymphoma and recent administration of anti‐CD20 therapy are risk factors for prolonged LOS and death for lymphoma patients hospitalized for Covid‐19. These findings may contribute to guide the management of lymphoma during the pandemic, support evaluating specific therapeutic approaches, and raise questions on the efficacy and timing of vaccination of this particular population.

The authors' full names, academic degrees, and affiliations are listed in the Appendix. Dr. Peffault de Latour can be contacted at regis .

Background Patients with lymphoma are immunocompromised because of the disease per se and its treatments. We aimed to describe the characteristics of patients with lymphoma hospitalized for Coronavirus Disease 2019 (Covid-19) and to analyze pre-Covid-19 determinants of mortality. Methods This retrospective multicentric cohort study used the Programme de Médicalisation des Systèmes d'Information database to identify all adult patients with lymphoma, hospitalized for Covid-19 in March and April 2020, in 12 hospitals of three French regions with pandemic outbreaks. The characteristics of lymphoma and Covid-19 were collected from medical charts. Findings Eighty-nine patients were included. The median age was 67 years (range, 19–92), 66% were male and 72% had a comorbidity. Most patients had B-cell non-Hodgkin lymphoma (86%) and had received a lymphoma treatment within one year (70%). With a median follow-up of 33 days from admission, 30-day overall survival was 71%, (95% confidence interval, 62–81%). In multivariable analysis, having an age ≥ 70 years (hazard ratio 2·87, 1·20–6·85, p = 0·02) and relapsed/refractory lymphoma (hazard ratio 2·54, 1·14–5·66, p = 0·02) were associated with mortality. Recent bendamustine treatment ( n = 9) was also pejorative (hazard ratio 3·20, 1·33–7·72, p = 0·01), but was strongly associated with relapsed/refractory lymphoma. Remarkably, 30-day overall survival for patients < 70 years of age without relapsed/refractory lymphoma was 88% (78% - 99%). Interpretation Thirty-day mortality was associated with being older and relapsed/refractory lymphoma. Survival of patients younger than 70 years without relapsed/refractory lymphoma was comparable to that of the general population. Funding There have been no specific funds to run this study.

Key Points• In AML with normal cytogenetics, age, response to induction, and FLT3-ITD allow for an estimate of outcome after allogeneic HSCT in CR1.• Neither variation of classical transplant techniques nor development of chronic GVHD outweighs the negative impact of FLT3-ITD.To analyze the influence of distinct combinations of molecular aberrations on outcome after allogeneic hematopoietic stem cell transplantation (HSCT) for cytogenetically normal acute myeloid leukemia (CN-AML), a retrospective registry analysis was performed on 702 adults undergoing HSCT in first complete remission (CR). Patients were grouped according to presence or absence of NPM1 mutations (NPM1 mut ) and FLT3 internal tandem duplications (FLT3-ITD). Double-negative patients were evaluated for mutations of the CCAAT/enhancer binding protein a gene (CEBPa). The influence of genotypes on relapse, non-relapse mortality, leukemia-free survival (LFS) and overall survival (OS), and a prognostic classification combining NPM1/FLT3-ITD profile and classical risk factors were calculated. Two-year OS from HSCT was 81 6 5% in NPM1 wt revealed excellent results both in patients with CEBPa mut and with a triple negative genotype (2-year OS: 100%/77 6 3%). In a Cox-model of predefined variables, age, FLT3-ITD and >1 course of chemotherapy to reach CR were risk factors associated with inferior outcome, regardless of NPM1 mutational status, variations of transplant protocols, or development of graft-versus-host disease. In a prognostic risk classification, 2-year OS/LFS rates were 88 6 3%/79 6 4% without any, 77 6 2%/73 6 3% with one, and 53 6 4%/50 6 4 with ‡2 risk factors (P 5

Chronic myeloid leukemia (CML) is a chronic disease resulting in myeloid cell expansion through expression of the BCR-ABL1 fusion transcript. Tyrosine kinase inhibitors (TKI) have significantly increased survival of patients with CML, and deep responders may consider stopping the treatment. However, more than 50% of patients relapse and restart TKI, subsequently suffering unknown toxicity. Because CML is a model immune system-sensitive disease, we hypothesize that chimeric antigen receptor (CAR) T cells targeting IL1 receptor-associated protein (IL1RAP) in quiescent CML stem cells may offer an opportunity for a permanent cure. In this study, we produced and molecularly characterized a specific monoclonal anti-IL1RAP antibody from which fragment antigen-binding nucleotide coding sequences were cloned as a single chain into a lentiviral backbone and secured with the suicide gene iCASP9/rimiducid system. Our CAR T-cell therapy exhibited cytotoxicity against both leukemic stem cells and, to a lesser extent, monocytes expressing IL1RAP, with no apparent effect on the hematopoietic system, including CD34 þ stem cells. This suggests IL1RAP as a tumor-associated antigen for immunotherapy cell targeting. IL1RAP CAR T cells were activated in the presence of IL1RAP þ cell lines or primary CML cells, resulting in secretion of proinflammatory cytokines and specifically killing in vitro and in a xenograft murine model. Overall, we demonstrate the proof of concept of a CAR T-cell immunotherapy approach in the context of CML that is applicable for young patients and primary TKI-resistant, intolerant, or allograft candidate patients. Significance: These findings present the first characterization and proof of concept of a chimeric antigen receptor directed against IL1RAP expressed by leukemic stem cells in the context of CML.

Neoplasms involving plasmacytoid Dendritic Cells (pDCs) include Blastic pDC Neoplasms (BPDCN) and other pDC proliferations, where pDCs are associated with myeloid malignancies: most frequently Chronic MyeloMonocytic Leukemia (CMML) but also Acute Myeloid Leukemia (AML), hereafter named pDC-AML. We aimed to determine the reactive or neoplastic origin of pDCs in pDC-AML, and their link with the CD34+ blasts, monocytes or conventional DCs (cDCs) associated in the same sample, by phenotypic and molecular analyses (targeted NGS, 70 genes). We compared 15 pDC-AML at diagnosis with 21 BPDCN and 11 normal pDCs from healthy donors. CD45low CD34+ blasts were found in all cases (10-80% of medullar cells), associated with pDCs (4-36%), monocytes in 14 cases (1-10%) and cDCs (2 cases, 4.8-19%). pDCs in pDC-AML harbor a clearly different phenotype from BPDCN: CD4+ CD56- in 100% of cases, most frequently CD303+, CD304+ and CD34+; lower expression of cTCL1 and CD123 with isolated lymphoid markers (CD22/CD7/CD5) in some cases, suggesting a pre-pDC stage. In all cases, pDCs, monocytes and cDC are neoplastic since they harbor the same mutations as CD34+ blasts. RUNX1 is the most commonly mutated gene: detected in all AML with minimal differentiation (M0-AML) but not in the other cases. Despite low number of cases, the systematic association between M0-AML, RUNX1 mutations and an excess of pDC is puzzling. Further evaluation in a larger cohort is required to confirm RUNX1 mutations in pDC-AML with minimal differentiation and to investigate whether it represents a proliferation of blasts with macrophage and DC progenitor potential.