Influence of thrombocytopenia on bleeding and vascular events in atrial fibrillation

Whether thrombocytopenia substantively increases the risk of hemorrhage associated with anticoagulation in patients with atrial fibrillation (AF) is not established. The purpose of this study was to compare rates of bleeding in patients with AF and thrombocytopenia (platelet count < 100 000/μL) to patients with AF and normal platelet counts (>150 000/μL). We performed a propensity score-matched, retrospective cohort study of adults (n = 1070) with a new diagnosis of AF who received a prescription for an oral anticoagulant between 2015 and 2020. The thrombocytopenia cohort was defined as having at least 2 platelet counts <100 000/μL on separate days in the period spanning the 12 weeks preceding the initiation of anticoagulation to 6 weeks after the initiation of anticoagulation. The primary end point was the 1-year cumulative incidence of major bleeding; secondary end points included clinically relevant bleeding, arterial and venous thrombotic events, and all-cause mortality. Patients with AF and thrombocytopenia experienced a higher 1-year cumulative incidence of major bleeding (13.3% vs 5.7%; P < .0001) and clinically relevant bleeding (24.5% vs 16.7%; P = .005) than the controls. Thrombocytopenia was identified as an independent risk factor for major bleeding (hazard ratio, 2.20; confidence interval, 1.36-3.58; P = .001), with increasing risk based on the severity of thrombocytopenia. The cumulative incidence of arterial thrombosis at 1 year was 3.6% in the group with thrombocytopenia and 1.5% in controls (Gray test, P = .08). These findings suggest that baseline platelet counts are an important biomarker for hemorrhagic outcomes in AF and that the degree of thrombocytopenia is an important factor in determining the level of risk.

Venous thromboembolism prophylaxis for hospitalized adult patients: a survey of US health care providers on attitudes and practices

Background

Venous thromboembolism (VTE) is a leading cause of preventable mortality among hospitalized patients, but appropriate risk assessment and thromboprophylaxis remain underutilized or misapplied.

Objectives

We conducted an electronic survey of US health care providers to explore attitudes, practices, and barriers related to thromboprophylaxis in adult hospitalized patients and at discharge.

Results

A total of 607 US respondents completed the survey: 63.1% reported working in an academic hospital, 70.7% identified as physicians, and hospital medicine was the most frequent specialty (52.1%). The majority of respondents agreed that VTE prophylaxis is important (98.8%; 95% CI: 97.6%-99.5%) and that current measures are safe (92.6%; 95% CI: 90.2%-94.5%) and effective (93.8%; 95% CI: 91.6%-95.6%), but only half (52.0%; 95% CI: 47.9%-56.0%) believed that hospitalized patients at their institution are on appropriate VTE prophylaxis almost all the time. One-third (35.4%) reported using a risk assessment model (RAM) to determine VTE prophylaxis need; 44.9% reported unfamiliarity with RAMs. The most common recommendation for improving rates of appropriate thromboprophylaxis was to leverage technology. A majority of respondents (84.5%) do not reassess a patient's need for VTE prophylaxis at discharge, and a minority educates patients about the risk (16.2%) or symptoms (18.9%) of VTE at discharge.

Conclusion

Despite guideline recommendations to use RAMs, the majority of providers in our survey do not use them. A majority of respondents believed that technology could help improve VTE prophylaxis rates. A majority of respondents do not reassess the risk of VTE at discharge or educate patients about this risk of VTE at discharge.

Phase 2 clinical trial evaluating abatacept in patients with steroid-refractory chronic graft-versus-host disease

Steroid-refractory chronic graft-versus-host disease (cGVHD) after allogeneic transplant remains a significant cause of morbidity and mortality. Abatacept is a selective costimulation modulator, used for the treatment of rheumatologic diseases, and was recently the first drug to be approved by the US Food and Drug Administration for the prophylaxis of acute graft-versus-host disease. We conducted a phase 2 study to evaluate the efficacy of abatacept in steroid-refractory cGVHD. The overall response rate was 58%, seen in 21 out of 36 patients, with all responders achieving a partial response. Abatacept was well tolerated with few serious infectious complications. Immune correlative studies showed a decrease in interleukin -1α (IL-1α), IL-21, and tumor necrosis factor α as well as decreased programmed cell death protein 1 expression by CD4+ T cells in all patients after treatment with abatacept, demonstrating the effect of this drug on the immune microenvironment. The results demonstrate that abatacept is a promising therapeutic strategy for the treatment of cGVHD. This trial was registered at www.clinicaltrials.gov as #NCT01954979.

Antiplatelet medications and intracranial hemorrhage in patients with primary brain tumors

BACKGROUND

Spontaneous intracranial hemorrhage (ICH) is a frequent and severe consequence of primary brain tumors. The safety of antiplatelet medications in this patient population is undefined.

OBJECTIVE

The primary objective was to determine whether antiplatelet medications are associated with an increased risk of ICH in patients with primary brain tumors.

PATIENTS/METHODS

We performed a matched, retrospective cohort study of patients with the diagnosis of primary brain tumor treated at our institution between 2010 and 2021. Radiographic images of all potential ICH events underwent blinded review. The primary end point of the study was the cumulative incidence of ICH at 1 year after tumor diagnosis.

RESULTS AND CONCLUSIONS

A total of 387 patients with primary brain tumors were included in the study population (130 exposed to antiplatelet agents, 257 not exposed). The most common malignancy was glioblastoma (n = 256, 66.1%). Among the intervention cohort, 119 patients received aspirin monotherapy. The cumulative incidence of any ICH at 1 year was 11.0% (95% CI, 5.3-16.6) in those receiving antiplatelet medications and 13.0% (95% CI, 8.5-17.6) in those not receiving antiplatelet medications (Gray test, p = 0.6). The cumulative incidence of major ICH was similar between the cohorts (3.3% in antiplatelet cohort vs 2.9% in control cohort, p = 1.0). This study did not identify an increased incidence of ICH in patients with primary brain tumors exposed to antiplatelet medications.

Targeting CD19 for diffuse large B cell lymphoma in the era of CARs: Other modes of transportation

CD19 is nearly ubiquitously expressed on B-lymphocytes and in B-cell malignancies. Although CD19-directed CAR T cells have greatly improved outcomes in B-cell malignancies, there are significant limitations with this therapy. CD19 can also be effectively targeted by other drug classes, such as monoclonal antibodies, antibody-drug conjugates, and bispecific T cell engagers or antibodies. However, the optimal patient selection and sequencing of these novel therapies has not yet been established. In this review, we discuss the utilization of CD19 as a target for the treatment of DLBCL, focusing on tafasitamab, loncastuximab tesirine, and blinatumomab. We provide a comprehensive review of the pivotal clinical trials, discussing the strength and limitations of the data for each agent. We explore the emerging evidence that CD19 expression is retained following exposure to these agents and that patients can be successfully re-challenged with anti-CD19 therapies of a different drug class upon disease relapse post-CAR T cells. Finally, we discuss how these drugs potentially fit into the most current treatment paradigm for DLBCL.

Oncology Fellows' Clinical Discussions, Perceived Knowledge, and Formal Training Regarding Medical Cannabis Use: A National Survey Study

PURPOSE

Evidence suggests that patients with cancer frequently use cannabis with medicinal intent and desire clinical guidance from providers. We aimed to determine whether oncology training adequately prepares fellows to discuss medical cannabis.

METHODS

A national survey study was conducted from January to March 2021. A questionnaire assessing oncology fellows' practices regarding cannabis recommendations in cancer care and their knowledge of its effectiveness and risks compared with conventional care for cancer-related symptoms was developed and sent to 155 US-based oncology training programs to distribute to trainees.

RESULTS

Forty programs from 25 states participated; of the 462 trainees across these programs, 189 responded (response rate of 40%). Of the participants, 52% were female; 52% were White, 33% Asian, and 5% Hispanic. Fifty-seven percent reported that they discussed medical cannabis with more than five patients in the preceding year; however, only 13% felt sufficiently informed to issue cannabis-related clinical recommendations. Twenty-four percent reported having received formal training regarding medical cannabis. Oncology fellows who reported having received prior training in medical cannabis were significantly more likely to discuss cannabis with patients (risk ratio: 1.37, 95% CI 1.06 to 1.75; P = .002) and feel sufficiently informed to discuss cannabis recommendations (risk ratio: 5.06; 95% CI, 2.33 to 10.99; P < .001). Many viewed the botanical as a useful adjunctive therapy that was at least as effective as conventional treatments for anorexia/cachexia (72%), nausea/vomiting (45%), and pain (41%).

CONCLUSION

Most oncology trainees not only reported engaging in discussions regarding medical cannabis with patients but also considered themselves insufficiently informed to make cannabis-related clinical recommendations. The discrepancy between the frequency of cannabis inquiries/discussions at the patient level and comfort/knowledge at the trainee provider level represents an unmet curricular need with implications for both graduate medical education and patient care.

Complete responses to odronextamab in two patients with diffuse large B-cell lymphoma refractory to chimeric antigen receptor T-cell therapy

Outcomes remain poor for patients with relapsed/refractory B-cell non-Hodgkin lymphoma (R/R B-NHL). While chimeric antigen receptor (CAR) T-cell therapy has revolutionised treatment, a significant proportion of patients relapse or fail to respond. Odronextamab is a CD20 × CD3 bispecific antibody that has demonstrated durable responses and a manageable safety profile in patients with R/R B-NHL in a first-in-human trial (NCT02290951). Here, we document two patients with diffuse large B-cell lymphoma refractory to CART-cell therapy. Both achieved complete responses that remain ongoing for ≥2 years following odronextamab. Neither patient experienced Grade ≥3 cytokine release syndrome or Grade ≥3 neurological adverse events during treatment.

COVID-19 and venous thromboembolism: A narrative review

COVID-19 (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2]) is associated with coagulopathy through numerous mechanisms. The reported incidence of venous thromboembolism (VTE) in hospitalized patients with COVID-19 has varied widely, and several meta-analyses have been performed to assess the overall prevalence of VTE. The novelty of this coronavirus strain along with its unique mechanisms for microvascular and macrovascular thrombosis has led to uncertainty as to how to diagnose, prevent, and treat thrombosis in patients affected by this virus. This review discusses the epidemiology and pathophysiology of thrombosis in the setting of SARS-CoV-2 infection along with an updated review on the preventative and treatment strategies for VTE associated with SARS-CoV-2 infection.

925. Infectious Complications Following Chimeric Antigen Receptor (CAR) T-cell Therapy

Background

Chimeric antigen receptor (CAR-T) T-cell therapy is a novel immunotherapy for cancer treatment in which patients are treated with targeted, genetically-modified T-cells. Common side effects include cytokine release syndrome, neurotoxicity, hypogammaglobulinemia, and increased susceptibility to infections. Long-term infectious outcomes are poorly characterized.

Methods

We retrospectively examined patients who received CAR-T therapy at BIDMC & MGH from July 2016 to March 2020 and evaluated bacterial, fungal, viral, and parasitic infections at 3 months intervals to 1 year following cell infusion. The incidence, timing, and outcomes of the infectious complications were evaluated.

Results

In total, there were 47 patients; averaging 61.4 years of age (±12 years). Primary indications for CAR-T therapy included diffuse large b-cell lymphoma (65%) and multiple myeloma (25%), chronic lymphocytic leukemia (2%) and mantle cell lymphoma (2%). Patients had received an average 4 ± 2.9 lines of chemotherapy prior to CAR-T infusion; 19 subjects (40%) had a history of prior autologous stem cell transplant. All patients received acyclovir for antiviral prophylaxis and most received either trimethoprim-sulfamethoxazole (24/47; 51%) or atovaquone (16/47; 34%) for pneumocystis prophylaxis. In the first year, 35/47 (74.5%) of subjects experienced at least one infection with an infection rate of 84.4/10,000 person days. Median time to first infection was 59 days (range 1-338 patient days). 31/47 (66.0%) subjects had at least one bacterial infection, with pulmonary (42/113; 37.2%) sources being the most common site of infection. 13/47 (27.7%) of patients had a viral infection (predominantly respiratory viral infections) and 6/47 (12.8%) had a proven or probable fungal infection. Death attributed to infection was noted in 2 subjects (4.3%), both related to COVID-19. Baseline IgG levels were significantly lower in the group with infections (p=0.028), while white blood cell count and absolute neutrophil counts were comparable.

Table 1. Baseline Demographic, Clinical Characteristics, and Outcomes of 47 Recipients of CAR-T Cell Therapy by Infection Status

Notes

BMI: body mass index; DLBCL: diffuse large B-cell lymphoma; CLL: chronic lymphocytic leukemia; Flu/Cy: Fludarabine/cyclophosphamide; IVIG: intravenous immunoglobulin; WBC: white blood cell count; ANC: absolute neutrophil count; ALC: absolute lymphocyte count.

Table 2. Characteristics of the 113 Infections in the 35 Subjects Who Developed Infections

Conclusion

Infectious complications, particularly of bacterial etiology, are common in the first year following CAR-T therapy. These data may inform future prophylactic strategies in this patient population.

Disclosures

Matthew Frigault, MD, Arcellx (Consultant)BMS (Consultant)Iovance (Consultant)Kite (Consultant)Novartis (Consultant) Jay A. Fishman, MD, Nothing to disclose Jon Arnason, MD, BMS/Juno (Advisor or Review Panel member)Regeneron (Advisor or Review Panel member)

Oncology trainees’ perceptions and knowledge of therapeutic cannabis use

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Background: Evidence shows that cancer patients are interested in learning about medicinal cannabis and frequently ask their oncologists for recommendations. To determine whether oncology training is adequately preparing physicians to address this topic, we conducted a national survey of oncology trainees to determine attitudes, practices, and knowledge about medical cannabis in cancer care. Methods: An interdisciplinary team developed an electronic questionnaire assessing trainees’ current practices regarding cannabis recommendations in cancer care and their knowledge of its effectiveness and risks compared with conventional care for cancer-related symptoms. We contacted 155 oncology training programs throughout the U.S. and asked that they distribute the survey to their trainees. Primary outcomes were: whether trainees reported discussing or recommending cannabis with/to patients and whether they felt sufficiently informed to make such recommendations. We presented data as proportions and used chi-square tests to compare proportions between groups. Results: Forty training programs from 25 states participated; of the 462 trainees in these programs, 187 completed surveys, yielding a response rate of 40%. Of the participants, 52% were female, 53% White, 33% Asian, and 5% Hispanic. One third (34%) graduated medical school before 2015, and 22% attended medical school outside the US. While 24% of trainees reported having received training regarding medical cannabis, only 12% felt sufficiently informed to make cannabis recommendations. Despite this, 91% reported having discussed cannabis with patients, and 58% reported recommending cannabis clinically to more than five patients in the prior year. Many viewed it as useful adjunctive therapy that was at least as effective as conventional treatments for: anorexia/cachexia (72%), nausea/vomiting (45%), and pain (41%). Over half (55%) believed that cannabis was beneficial to patients at the end of life; 31%, patients in active treatment; 11%, cancer survivors; 20%, the elderly with cancer and 16%, young adults with cancer. Peer-reviewed material (30%), lectures or webinars by another physician (29%), and patients and their families (22%) were the most commonly cited sources of information regarding medical cannabis. Oncologists who reported at least one area of focus as supportive/palliative care were more likely to feel sufficiently informed to make recommendations than oncologists without this focus (17% vs. 4%, P = 0.01); no other demographic or practice characteristics were associated with feeling sufficiently informed (all P > 0.10). Conclusions: Although most oncology trainees discuss cannabis use with their patients, the majority do not feel sufficiently informed about its use in cancer care. This represents an unmet need in contemporary oncology training, trainee satisfaction, and patient care.

Abstract 512: Bcl11b is a Newly Identified Regulator of Vascular Smooth Muscle Function and Stiffness

Background: B-cell leukemia 11b (Bcl11b) is a zinc-finger transcription factor known as master regulator of T lymphocytes and neuronal development during embryogenesis. However, a role for Bcl11b in the cardiovascular system has never been described. Based on human findings from a genome-wide association study (GWAS) that a gene desert region downstream of BCL11B , known to function as BCL11B enhancer, harbors single nucleotide polymorphisms (SNPs) associated with increased arterial stiffness, we sought to examine relations between Bcl11b and arterial function.

Methods and Results: We found for the first time that Bcl11b is expressed in the vascular smooth muscle (VSM) of human and murine vasculature and transcriptionally regulates the expression of VSM contractile proteins smooth muscle myosin and smooth muscle α-actin. Lack of Bcl11b in VSM-specific Bcl11b null mice (BSMKO) resulted in an increased expression of Ca ++ -calmodulin-dependent serine/threonine phosphatase calcineurin in BSMKO VSM cells and aortas, which were inversely correlated with levels of phosphorylated VASP S239 , a calcineurin de-phosphorylation target. Decreased pVASP S239 in BSMKO aortas was associated with increased actin polymerization (F/G actin ratio), consistent with pVASP S239 ’s function as regulator of cytoskeletal actin rearrangements, and was normalized by treatment with calcineurin inhibitor cyclosporine A. Functionally, Bcl11b deletion in VSM cells translated in increased aortic force, stress and wall tension, measured ex vivo in BSMKO aortas in organ baths, and increased pulse wave velocity, the in vivo index of arterial stiffness, in BSMKO mice compared to WT littermates. Moreover, Bcl11b and pVASP S239 expression were decreased in aortas of obese and aged mice, two models of arterial stiffness. Bcl11b deletion in VSM had no effect on baseline blood pressure or angiotensin II-induced hypertension, measured in conscious WT and BSMKO mice by radiotelemetry, but dramatically increased the incidence of angII-induced aortic aneurysms in BSMKO mice.

Conclusions: Taken together, our results identify VSM Bcl11b as a novel and crucial regulator of VSM cell phenotype and vascular structural and functional integrity