SOCS3 deregulation contributes to aberrant activation of the JAK/STAT pathway in precursor T-cell neoplasms.

Despite the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway being frequently altered in T-ALL/LBL, no specific therapy has been approved for T-ALL/LBL patients with constitutive signalling by JAK/STAT, so there is an urgent need to identify pathway members that may be potential therapeutic targets. In the present study, we searched for JAK/STAT pathway members potentially modulated through aberrant methylation and identified SOCS3 hypermethylation as a recurrent event in T-ALL/LBL. Additionally, we explored the implications of SOCS3 deregulation in T-ALL/LBL and demonstrated that SOCS3 counteracts the constitutive activation of the JAK/STAT pathway through different molecular mechanisms. Therefore, SOCS3 emerges as a potential therapeutic target in T-ALL/LBL.

Primary Effusion Lymphoma, Multicentric Castleman's Disease, and Kaposi's Sarcoma in an HHV-8 and HIV-Positive Patient: A Case Report.

Primary effusion lymphoma (PEL), Kaposi's sarcoma (KS), and multicentric Castleman's disease (MCD) is an uncommon group of diseases included in the same spectrum with related characteristics. The coexistence of all of them in the same individual is a rare occurrence. We present the case of a 25-year-old patient diagnosed with human immunodeficiency virus (HIV) and the development of all these related pathologies. Despite the use of intensive treatment according to the latest recommendations, the evolution was unfavorable. This case reflects the need for new therapies and research in this field.

Identification of seasonal variation in the diagnosis of acute myeloid leukaemia: a population-based study.

Until now, the role that seasonal factors play in the aetiology of acute myeloid leukaemia (AML) has been unclear. Demonstration of seasonality in AML diagnosis would provide supportive evidence of an underlying seasonal aetiology. To investigate the potential seasonal and long-term trends in AML diagnosis in an overall population and in subgroups according to sex and age, we used population-based data from a Spanish hospital discharge registry. We conducted a larger study than any to date of 26 472 cases of AML diagnosed in Spain between 2004 and 2015. Using multivariable Poisson generalized linear autoregressive moving average modelling, we found an upward long-term trend, with monthly incidence rates of AML annually increasing by 0.4% [95% confidence interval (CI), 0.2%-0.6%; p = 0.0011]. January displayed the highest incidence rate of AML, with a minimum average difference of 7% when compared to February (95% CI, 2%-12%; p = 0.0143) and a maximum average difference of 16% compared to November (95% CI, 11%-21%; p < 0.0001) and August (95% CI, 10%-21%; p < 0.0001). Such seasonal effect was consistent among subgroups according to sex and age. Our finding that AML diagnosis is seasonal strongly implies that seasonal factors, such as infectious agents or environmental triggers, influence the development and/or proliferation of disease, pointing to prevention opportunities.

Ventilation/perfusion (V/Q) scanning in contemporary patients with pulmonary embolism: utilization rates and predictors of use in a multinational study.

Ventilation/perfusion (V/Q) imaging and computed tomography pulmonary angiography (CTPA) are common tools for acute pulmonary embolism (PE) diagnosis. Limited contemporary data exist about the utilization of each modality, including the predictors of using V/Q versus CTPA. We used the data from patients diagnosed with PE using V/Q or CTPA from 2007 to 2019 in Registro Informatizado Enfermedad ThromboEmbolica, an international prospective registry of patients with venous thromboembolism. Outcomes was to determine the trends in utilization of V/Q vs. CTPA and, in a contemporary subgroup fitting with current practices, to evaluate predictors of V/Q use with multivariable logistic regression. Among 26,540 patients with PE, 89.2% were diagnosed with CTPA, 7.1% with V/Q and 3.7% with > 1 thoracic imaging modality. Over time, the proportional use of V/Q scanning declined (13.9 to 3.3%, P < 0.001). In multivariable analysis, heart failure history (odds ratio [OR]:1.5; 95% confidence interval [CI] 1.14-1.98), diabetes ([OR 1.71; 95% CI 1.39-2.10]), moderate and severe renal failure (respectively [OR 1.87; 95% CI 1.47-2.38] and [OR 9.36; 95% CI 6.98-12.55]) were the patient-level predictors of V/Q utilization. We also observed an influence of geographical and institutional factors, partly explained by time-limited V/Q availability (less use over weekends) and regional practices. Use of V/Q for the diagnosis of PE decreased over time, but it still has an important role in specific situations with an influence of patient-related, institution-related and logistical factors. Local and regional resources should be evaluated to improve V/Q accessibility than could benefit for this population.

Consensus document of the Spanish Society of Digestives Diseases and the Spanish Society of Thrombosis and Haemostasis on massive nonvariceal gastrointestinal bleeding and direct-acting oral anticoagulants.

INTRODUCTION: there is limited experience and understanding of massive nonvariceal gastrointestinal bleeding during therapy with direct-acting oral anticoagulants. OBJECTIVES: to provide evidenced-based definitions and recommendations. METHODS: a consensus document developed by the Spanish Society of Digestives Diseases and the Spanish Society of Thrombosis and Haemostasis using modified Delphi methodology. A panel was set up of 24 gastroenterologists with experience in gastrointestinal bleeding, and consensus building was assessed over three rounds. Final recommendations are based on a systematic review of the literature using the GRADE system. RESULTS: panelist agreement was 91.53 % for all 30 items as a group, a percentage that was improved during rounds 2 and 3 for items where clinical experience is lower. Explicit disagreement was only 1.25 %. A definition of massive nonvariceal gastrointestinal bleeding in patients on direct-acting oral anticoagulants was established, and recommendations to optimize this condition's management were developed. CONCLUSION: the approach to these critically ill patients must be multidisciplinary and protocolized, optimizing decisions for an early identification of the condition and patient stabilization according to the tenets of damage control resuscitation. Thus, consideration must be given to immediate anticoagulation reversal, preferentially with specific antidotes (idarucizumab for dabigatran and andexanet alfa for direct factor Xa inhibitors); hemostatic resuscitation, and bleeding point identification and management.

Presenting Characteristics, Treatment Patterns, and Outcomes among Patients with Venous Thromboembolism during Hospitalization for COVID-19.

Venous thromboembolism (VTE) is common in patients with coronavirus disease-2019 (COVID-19). However, limited data exist on patient characteristics, treatments, and outcomes. To describe the clinical characteristics, treatment patterns, and short-term outcomes of patients diagnosed with VTE during hospitalization for COVID-19. This is a prospective multinational study of patients with incident VTE during the course of hospitalization for COVID-19. Data were obtained from the Registro Informatizado de la Enfermedad TromboEmbólica (RIETE) registry. All-cause mortality, VTE recurrences, and major bleeding during the first 10 days were separately investigated for patients in hospital wards versus those in intensive care units (ICUs). As of May 03, 2020, a total number of 455 patients were diagnosed with VTE (83% pulmonary embolism, 17% isolated deep vein thrombosis) during their hospital stay; 71% were male, the median age was 65 (interquartile range, 55-74) years. Most patients (68%) were hospitalized in medical wards, and 145 in ICUs. Three hundred and seventeen (88%; 95% confidence interval [CI]: 84-91%) patients were receiving thromboprophylaxis at the time of VTE diagnosis. Most patients (88%) received therapeutic low-molecular-weight heparin, and 15 (3.6%) received reperfusion therapies. Among 420 patients with complete 10-day follow-up, 51 (12%; 95% CI: 9.3-15%) died, no patient recurred, and 12 (2.9%; 95% CI: 1.6-4.8%) experienced major bleeding. The 10-day mortality rate was 9.1% (95% CI: 6.1-13%) among patients in hospital wards and 19% (95% CI: 13-26%) among those in ICUs. This study provides characteristics and early outcomes of patients diagnosed with acute VTE during hospitalization for COVID-19. Additional studies are needed to identify the optimal strategies to prevent VTE and to mitigate adverse outcomes associated.

Exploiting the passenger ACO1-deficiency arising from 9p21 deletions to kill T-cell lymphoblastic neoplasia cells.

Precursor T-cell lymphoblastic neoplasms are aggressive malignancies in need for more effective and specific therapeutic treatments. A significant fraction of these neoplasms harbor deletions on the locus 9p21, targeting the tumor suppressor CDKN2A but also deleting the aconitase 1 (ACO1) gene, a neighboring housekeeping gene involved in cytoplasm and mitochondrial metabolism. Here we show that reducing the aconitase activity with fluorocitrate decreases the viability of T-cell lymphoblastic neoplasia cells in correlation to the differential aconitase expression. The consequences of the treatment were evidenced in vitro using T-cell lymphoblastic neoplasia cell lines exhibiting 9p21 deletions and variable levels of ACO1 expression or activity. Similar results were observed in melanoma cell lines, suggesting a true potential for fluorocitrate in different cancer types. Notably, ectopic expression of ACO1 alleviated the susceptibility of cell lines to fluorocitrate and, conversely, knockdown experiments increased susceptibility of resistant cell lines. These findings were confirmed in vivo on athymic nude mice by using tumor xenografts derived from two T-cell lines with different levels of ACO1. Taken together, our results indicate that the non-targeted ACO1 deficiency induced by common deletions exerts a collateral cellular lethality that can be used as a novel therapeutic strategy in the treatment of several types of cancer.

RNA-Seq reveals the existence of a CDKN1C-E2F1-TP53 axis that is altered in human T-cell lymphoblastic lymphomas.

BACKGROUND: Precursor T-cell lymphoblastic lymphomas (T-LBL) are rare aggressive hematological malignancies that mainly develop in children. As in other cancers, the loss of cell cycle control plays a prominent role in the pathogenesis in these malignancies that is primarily attributed to loss of CDKN2A (encoding protein p16INK4A). However, the impact of the deregulation of other genes such as CDKN1C, E2F1, and TP53 remains to be clarified. Interestingly, experiments in mouse models have proven that conditional T-cell specific deletion of Cdkn1c gene may induce a differentiation block at the DN3 to DN4 transition, and that the loss of this gene in the absence of Tp53 led to aggressive thymic lymphomas. RESULTS: In this manuscript, we demonstrated that the simultaneous deregulation of CDKN1C, E2F1, and TP53 genes by epigenetic mechanisms and/or the deregulation of specific microRNAs, together with additional impairing of TP53 function by the expression of dominant-negative isoforms are common features in primary human T-LBLs. CONCLUSIONS: Previous experimental work in mice revealed that T-cell specific deletion of Cdkn1c accelerates lymphomagenesis in the absence of Tp53. If, as expected, the consequences of the deregulation of the CDKN1C-E2F1-TP53 axis were the same as those experimentally demonstrated in mouse models, the disruption of this axis might be useful to predict tumor aggressiveness, and to provide the basis towards the development of potential therapeutic strategiesin human T-LBL.

Direct vitamin K antagonist anticoagulant treatment health care costs in patients with non-valvular atrial fibrillation.

BACKGROUND: There is evidence suggesting that most thromboembolic complications could be prevented with adequate pharmacological anticoagulation. We estimated the direct health care costs of anticoagulant treatment with oral vitamin K antagonists in patients diagnosed with non-valvular atrial fibrillation. METHODS: This observational study examined the clinical records of patients diagnosed with non-valvular atrial fibrillation who received anticoagulant treatment with oral vitamin K antagonists. Data from clinical records were used in the study: international normalized ratio, number of monitoring visits, type of anticoagulant, hospital admissions from complications, and concomitant medication. Drug cost was calculated based on the official Spanish Ministry of Health price list. Monitoring expenses were included the cost of the medical supplies used in the procedures. Hospitalization costs were calculated using the Diagnosis Related Group price for each case. Hospital visits costs were calculated by one of four different scenarios, using either the invoice rates for the regional health care authority or cost per visit as established by analytical accounting methods. RESULTS: We collected data from 1,257 patients diagnosed with non-valvular atrial fibrillation who were receiving oral anticoagulant therapy. Depending on the scheme used, the direct health care costs for these patients ranged from €423,695 - €1,436,038 per annum. The average cost per patient varied between €392 - €1,341, depending on the approach used. Patients with international normalized ratio values within the therapeutic range on 25% of their visits represented an average cost between €441.70 - €1,592. Those within the therapeutic range on 25%-50% of visits had associated costs of €512.37 - €1,703.91. When international normalized ratio values were within the therapeutic range on 50% - 75% of the visits, the costs ranged between €400.80- €1,375.74. The average cost was €305.23 - €1,049.84 when the values were within the therapeutic range for over 75% of visits. CONCLUSIONS: Most direct health care costs associated with the sampled patients arise from the specialist-care monitoring required for the treatment. Good monitoring is inversely related to direct health care costs.

External validation of the PE-SARD risk score for predicting early bleeding in acute pulmonary embolism in the RIETE Registry.

INTRODUCTION: The PE-SARD score (syncope, anemia, renal dysfunction) was developed to predict the risk of major bleeding in the acute phase of pulmonary embolism (PE). METHODS: We analyzed data from 50,686 patients with acute PE included in the RIETE registry to externally validate the PE-SARD score. We calculated the overall reliability of the PE-SARD score, as well as discrimination and calibration for predicting the risk of major bleeding at 30 days. The performance of PE-SARD was compared to the BACS and PE-CH models. RESULTS: During the first 30 days, 640 patients (1.3 %) had a major bleeding event. The incidence of major bleeding within 30 days was 0.6 % in the PE-SARD-defined low-risk group, 1.5 % in the intermediate-risk group, and 2.5 % in the high-risk group, for an OR of 2.22 (95 % CI, 2.02-2.43) for the intermediate-risk group (vs low-risk group), and 3.94 for the high-risk group (vs low-risk group). The corresponding sensitivity was 81.1 % (intermediate/high vs low risk), and specificity was 85.9 % (95 % CI, 85.8-86.1) (low/intermediate vs high risk). The applicability of PE-SARD was consistent across clinically relevant patient subgroups and over shorter time periods of follow-up (i.e., 3 and 7 days). The C-index was 0.654 and calibration was excellent. The PE-SARD bleeding score improved the major bleeding risk prediction compared with the BACS and PE-CH scores. CONCLUSIONS: The PE-SARD score identifies PE patients with a higher risk of bleeding, which could assist providers for potentially adjusting PE management, in a framework of shared decision-making with individual patients.

Daratumumab and Nelarabine Treatment as Salvage Therapy for T-Lymphoblastic Lymphoma: A Case Report.

T-cell lymphoblastic lymphoma is an uncommon lymphoid neoplasm in adults, although more frequent in children and teenagers, that often affects the mediastinum and bone marrow, requiring intensive chemotherapy protocols. Its prognosis is poor if a cure is not achieved with first-line treatments. We present a case report of a 19-year-old man diagnosed with this type of lymphoma due to significant respiratory distress and a mediastinal mass. He received treatment according to the hyper-CVAD regimen, with a complete metabolic response. However, seven months later a new mediastinal growth was observed, leading to salvage treatment with a combination of nelarabine and daratumumab. We observed not only refractoriness, but also leukemization, which prompted consideration of hematopoietic stem cell transplantation. Based on this case, we conducted a review of pharmacological treatment options for refractory or relapsed lymphoblastic lymphoma, as well as the role of radiotherapy in managing mediastinal disease. This case report highlights the limited evidence available regarding later-line treatments, with unusual reports regarding employing our combination of daratumumab and nelarabine, and emphasizes the importance of achieving cures in the first line of treatment.

Thrombotic risk and features of patients with inferior vena cava agenesis: a multicentre, retrospective, observational study.

BACKGROUND: Inferior vena cava agenesis (IVCA) is a rare anomaly predisposing affected people to lower-limb venous thrombosis with low frequency of pulmonary embolism. Antenatal thrombosis and inherited thrombophilia have been suggested as causes of IVCA. However, there is little evidence on the clinical course and management of this condition. We designed a patient registry to assess the thrombotic risk and features of IVCA. METHODS: In this this multicentre, retrospective, observational study, we included patients with IVCA diagnosed by routine imaging from 20 hospitals in Spain (n=18), Portugal (n=1), and Italy (n=1). Patients were identified from a systematic search in radiology databases using data extraction software (cohort A) and alternative searches in medical records for confirmed IVCA (cohort B; option allowed when systematic approaches were unapplicable). Primary outcomes were clinical and imaging features, thrombotic risk, phenotype of IVCA-associated thrombosis, anticoagulant treatment, and the results of thrombophilia testing. FINDINGS: We included patients with IVCA diagnosed by routine imaging studies done between Jan 1, 2010, and Dec 31, 2022. In the systematic search, 4 341 333 imaging exams were screened from the radiology databases of eight centres. 122 eligible patients were enrolled in cohort A. A further 95 patients were identified by screening medical records at 12 centres, of whom 88 were eligible and included in cohort B, making a combined cohort of 210 patients. 96 (46%) of 210 patients were female and 200 (95%) were European or Hispanic. 60 (29%) of 210 patients had hepatic IVC interruption, whereas 150 (71%) had extrahepatic IVCA. In cohort A, 65 (53%) of 122 patients had venous thrombosis, with an estimated annual risk of 1·15% (95% CI 0·89-1·46). Extrahepatic IVCA was associated with a greater risk of venous thrombosis than hepatic IVCA (56 [67%] of 84 patients vs nine [24%] of 38 patients, odds ratio 5·31, 95% CI 2·27-12·43; p<0·0001). Analysis of 126 patients with venous thrombosis pooled from cohorts A and B showed early-onset (median age 34·6 years, IQR 23·3-54·3) and recurrent events (50 [40%] of 126 patients). Patients with extrahepatic IVCA had greater proportions of lower-limb venous thrombosis (95 [87%] of 109 vs nine [53%] of 17, p=0·0010) and recurrence (48 [44%] of 109 vs two [12%] of 17, p=0·015), but lower rates of pulmonary embolism (10 [10%] of 99 vs four [33%] of 12, p=0·044) than did patients with hepatic IVCA. 77 (63%) of 122 patients with thrombosis underwent indefinite anticoagulation. 32 (29%) of 111 patients (29 [34%] of 86 with thrombosis) had coexisting thrombophilias. The recurrence risk was lower for patients receiving indefinite anticoagulation (adjusted odds ratio 0·24, 95% CI 0·08-0·61; p=0·010), and greater for thrombophilias (3·19, 1·09-9·32; p=0·034). INTERPRETATION: This evaluation of a large patient cohort demonstrates the high thrombotic burden of IVCA. We have identified two distinct forms of IVCA, hepatic and extrahepatic, suggesting different underlying mechanisms. Beyond clinical characterisation, we draw attention to this orphan disease and highlight the need for its study and improved care. FUNDING: Spanish Society of Thrombosis and Haemostasis, Instituto de Salud Carlos III, FEDER, Fundación Séneca.

Invasive Cutaneous Candidiasis, Autoimmune Hemolytic Anemia and Pancytopenia: A Challenging Scenario for Waldenström Macroglobulinemia in an Elderly Patient.

Waldenström macroglobulinemia (WM) is a slowly progressive hematologic malignancy that usually responds rapidly to treatment. Being a lymphoplasmacytoid neoplasm, it is associated with a monoclonal IgM component, which may be associated with multiple manifestations and symptoms. We report the case of a 77-year-old woman diagnosed with WM following the development of severe and sudden pancytopenia associated with a cold agglutinin syndrome. In order to treat the WM and the underlying hemolysis, treatment with rituximab, corticosteroids and cyclophosphamide was started. Despite the improvement in hemolysis parameters, pancytopenia persisted, and we started a second line with ibrutinib. During treatment the patient developed an uncommon invasive fungal infection (IFI) with bone marrow granulomatosis and myelofibrosis. This case shows an unusual clinical course with a poor hematopoietic response to treatment and a large number of intercurrent complications.

Emergency department management of atrial fibrillation: 2023 consensus from the Spanish Society of Emergency Medicine (SEMES), the Spanish Society of Cardiology (SEC), and the Spanish Society of Thrombosis and Hemostasis (SETH). / Manejo de la fibrilación auricular en los servicios de urgencias hospitalarios: actualización a 2023 del consenso de la Sociedad Española de Medicina de Urgencias (SEMES), la Sociedad Española de Cardiología (SEC) y la Sociedad Española de Trombosis y Hemostasia (SETH).

OBJECTIVES: Atrial fibrillation (AF) is the most prevalent sustained arrhythmia managed in emergency departments, and the already high prevalence of this arrhythmia is increasing in Spain. This serious condition associated with increased mortality and morbidity has a negative impact on patient quality of life and the functioning of the health care system. The management of AF requires consideration of diverse clinical variables and a large number of possible therapeutic approaches, justifying action plans to coordinate the work of several medical specialties in the interest of providing appropriate care and optimizing resources. This consensus statement brings together recommendations for emergency department management of AF based on available evidence adapted to special circumstances. The statement was drafted by a multidisciplinary team of specialists from the Spanish Society of Emergency Medicine (SEMES), the Spanish Society of Cardiology (SEC), and the Spanish Society of Thrombosis and Hemostasis (SETH). Strategies for stroke prophylaxis, measures to bring heart rate and heart rhythm under control, and related diagnostic and logistic issues are discussed in detail.

OBJETIVO: La fibrilación auricular (FA) es la arritmia sostenida de mayor prevalencia en los servicios de urgencias (SU), y en España presenta una frecuentación elevada y creciente. Esta arritmia es una enfermedad grave, que incrementa la mortalidad y asocia una relevante morbilidad e impacto en la calidad de vida de los pacientes y en el funcionamiento de los servicios sanitarios. La diversidad de aspectos clínicos a considerar y el elevado número de opciones terapéuticas posibles justifican la implementación de estrategias de actuación coordinadas entre los diversos profesionales implicados, con el fin de incrementar la adecuación del tratamiento y optimizar el uso de recursos. Este documento, realizado por un grupo multidisciplinario de expertos en arritmias cardiacas miembros de la Sociedad Española de Medicina de Urgencias y Emergencias, la Sociedad Española de Cardiología y la Sociedad Española de Trombosis y Hemostasia, recoge las recomendaciones para el manejo de la FA en los SU hospitalarios, basadas en la evidencia disponible y adaptadas a las especiales circunstancias de los mismos. En él se analizan con detalle las estrategias de profilaxis tromboembólica, control de frecuencia y control del ritmo, y los aspectos logísticos y diagnósticos relacionados.

COVID-19 Severity and Survival over Time in Patients with Hematologic Malignancies: A Population-Based Registry Study.

Mortality rates for COVID-19 have declined over time in the general population, but data in patients with hematologic malignancies are contradictory. We identified independent prognostic factors for COVID-19 severity and survival in unvaccinated patients with hematologic malignancies, compared mortality rates over time and versus non-cancer inpatients, and investigated post COVID-19 condition. Data were analyzed from 1166 consecutive, eligible patients with hematologic malignancies from the population-based HEMATO-MADRID registry, Spain, with COVID-19 prior to vaccination roll-out, stratified into early (February-June 2020; n = 769 (66%)) and later (July 2020-February 2021; n = 397 (34%)) cohorts. Propensity-score matched non-cancer patients were identified from the SEMI-COVID registry. A lower proportion of patients were hospitalized in the later waves (54.2%) compared to the earlier (88.6%), OR 0.15, 95%CI 0.11-0.20. The proportion of hospitalized patients admitted to the ICU was higher in the later cohort (103/215, 47.9%) compared with the early cohort (170/681, 25.0%, 2.77; 2.01-3.82). The reduced 30-day mortality between early and later cohorts of non-cancer inpatients (29.6% vs. 12.6%, OR 0.34; 0.22-0.53) was not paralleled in inpatients with hematologic malignancies (32.3% vs. 34.8%, OR 1.12; 0.81-1.5). Among evaluable patients, 27.3% had post COVID-19 condition. These findings will help inform evidence-based preventive and therapeutic strategies for patients with hematologic malignancies and COVID-19 diagnosis.

Therapeutic versus Prophylactic Bemiparin in Hospitalized Patients with Nonsevere COVID-19 Pneumonia (BEMICOP Study): An Open-Label, Multicenter, Randomized, Controlled Trial.

Thromboprophylaxis with low molecular weight heparin in hospitalized patients with COVID-19 is mandatory, unless contraindicated. Given the links between inflammation and thrombosis, the use of higher doses of anticoagulants could improve outcomes. We conducted an open-label, multicenter, randomized, controlled trial in adult patients hospitalized with nonsevere COVID-19 pneumonia and elevated D-dimer. Patients were randomized to therapeutic-dose bemiparin (115 IU/kg daily) versus standard prophylaxis (bemiparin 3,500 IU daily), for 10 days. The primary efficacy outcome was a composite of death, intensive care unit admission, need of mechanical ventilation support, development of moderate/severe acute respiratory distress, and venous or arterial thrombosis within 10 days of enrollment. The primary safety outcome was major bleeding (International Society on Thrombosis and Haemostasis criteria). A prespecified interim analysis was performed when 40% of the planned study population was reached. From October 2020 to May 2021, 70 patients were randomized at 5 sites and 65 were included in the primary analysis; 32 patients allocated to therapeutic dose and 33 to standard prophylactic dose. The primary efficacy outcome occurred in 7 patients (22%) in the therapeutic-dose group and 6 patients (18%) in the prophylactic-dose (absolute risk difference 3.6% [95% confidence interval [CI], -16% -24%]; odds ratio 1.26 [95% CI, 0.37-4.26]; p = 0.95). Discharge in the first 10 days was possible in 66 and 79% of patients, respectively. No major bleeding event was registered. Therefore, in patients with COVID-19 hospitalized with nonsevere pneumonia but elevated D-dimer, the use of a short course of therapeutic-dose bemiparin does not appear to improve clinical outcomes compared with standard prophylactic doses. Trial Registration: ClinicalTrials.gov NCT04604327.