Oo, Thein Hlaing

Abstract Standard treatment of catheter-associated upper extremity deep vein thrombosis (UE-DVT) is anticoagulation, although catheters are often removed for this indication. The optimal time for catheter removal and whether the act and/or timing of catheter removal is associated with pulmonary embolism (PE) remain unknown. A retrospective cohort study was performed at 8 participating institutions through the Venous thromboEmbolism Network US. Patients with hematologic malignancies and central venous catheter (CVC)–associated UE-DVT were included from 1 January 2010 through 31 December 2016. The primary outcome was objectively confirmed PE within 7 days of UE-DVT diagnosis in anticoagulated patients comparing early (≤48 hours) vs delayed (>48 hours) catheter removal. A total of 626 patients were included, among whom 480 were treated with anticoagulation. Among anticoagulated patients, 255 underwent early CVC removal, while 225 had delayed or no CVC removal; 146 patients received no anticoagulation, among whom 116 underwent CVC removal alone. PE within 7 days occurred in 2 patients (0.78%) with early removal compared with 1 patient (0.44%) with delayed or no CVC removal (P > .9). PE or any cause of death within 7 days occurred in 3 patients in both the early removal (1.18%) and delayed/no removal (1.33%) groups (P > .9). In patients treated with CVC removal only (no anticoagulation), there were no PEs but 3 deaths within 7 days. In patients with hematological malignancy and CVC-associated UE-DVT, early removal of CVCs was not associated with an increased risk of PE compared with delayed or no removal.

Background: Standard treatment for catheter-associated upper extremity deep vein thrombosis (UEDVT) is anticoagulation. If catheter removal is otherwise indicated, it is unknown if catheter removal close to the time of initiation of anticoagulation is associated with a higher incidence of pulmonary embolization. Methods: A multicenter retrospective cohort study was performed at 8 participating institutions through the Venous thromboEmbolism Network US (VENUS). ICD-9/10 codes were used to identify patients with hematologic malignancies and upper extremity deep vein thrombosis (UEDVT) from 1/1/2010 through 12/31/2016. Identified patients underwent medical record review to verify diagnostic codes and determine if a catheter was associated with the upper extremity DVT and assess for outcomes. Patients were excluded if the UEDVT was not catheter provoked or if there were associated lower extremity DVT and/or pulmonary emboli. The anticoagulant start and finish date as well as the timing of the catheter removal, total follow up, and death were recorded. Patients started on anticoagulation at the time of their diagnosis were divided into two groups: 1) anticoagulation with delayed (> 48 hrs) or no catheter removal and 2) anticoagulation with early catheter removal (< 48 hrs). Outcomes were also assessed in patients with no anticoagulation initiation but catheter removal as the only treatment. The primary outcome was clinically identified pulmonary emboli within 7 days and the secondary outcome was pulmonary emboli or death from any cause within 7 days. Baseline characteristics were compared between groups using Χ2 for categorical variables, 2-tailed t-tests for continuous variables, and Wilcoxon rank-sum for nonparametric continuous variables. Fisher's exact test was used to evaluate the primary and secondary outcomes. Results: 663 patients with hematologic malignancies and isolated catheter-associated UEDVT underwent chart review. 512 patients were treated with anticoagulation of which 312 underwent early catheter removal while 200 had delayed or no catheter removal (Figure 1). 151 patients received no anticoagulation and 119 underwent catheter removal alone as the treatment for the DVT. Among patients who were treated with anticoagulation, the mean age was 52.6 years and 44% were male; age and sex did not differ between patients with early vs. delayed or no catheter removal (Table 1). Type of hematologic malignancy, type of central catheter, and DVT location were significantly different between groups. Patients with PICC lines were more likely to have early catheter removal (71% vs. 49%). The median platelet count was not significantly different among patients treated with anticoagulation, but was lower in patients treated with catheter removal only. Most patients were initially treated with low molecular weight heparins (LMWH) and anticoagulation treatment did not differ between groups. Pulmonary emboli within 7 days occurred in 2 patients (0.64%) with early catheter removal compared to 1 patient (0.5%) with delayed or no removal (p=1.0). Pulmonary emboli or any cause death within 7 days occurred in 3 patients (1.0%) with early removal compared to 3 patients (1.5%) with delayed or no removal (p=0.68). In patients treated with catheter removal only (no anticoagulation), there were no pulmonary emboli within 7 days and 3 deaths. All 3 patients with pulmonary emboli within 7 days had PICC lines and leukemia/MDS and the sites of most proximal DVT involvement were brachiocephalic veins (2 patients) and subclavian vein (1 patient). Conclusions: In patients with hematological malignancy and catheter-associated UEDVT, removal of catheters within 48 hours was not associated with increased risk of pulmonary emboli compared to delayed or no removal. Disclosures Billett: Albert Einstein College of Medicine: Patents & Royalties: Patent application pending for NETs AI software. Gaddh:Pfizer: Membership on an entity's Board of Directors or advisory committees; Celgene: Membership on an entity's Board of Directors or advisory committees; Hema Biologics: Membership on an entity's Board of Directors or advisory committees; Pharmacyclics LLC: Membership on an entity's Board of Directors or advisory committees. Oo:Medical Education Speakers Network: Honoraria; Janssen and Janssen: Other: Research: site co-investigator . Jaglal:NOVARTIS: Consultancy. Streiff:Janssen: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding; Daiichi-Sankyo: Consultancy, Honoraria; Bayer: Consultancy, Honoraria; Pfizer: Consultancy, Honoraria; Portola: Consultancy, Honoraria; Roche: Research Funding. Baumann Kreuziger:Vaccine Injury Compensation Program: Consultancy; CSL Behring: Consultancy.

Abstract Introduction: The development of immune checkpoint inhibitors (ICPis) has ushered in a new paradigm for the treatment of both solid and liquid malignancies. However, these therapies, which promote an activated T cell phenotype, can cause a unique spectrum of autoimmune toxicities known as immune-related adverse events (IRAEs), which can affect a variety of organ systems. Autoimmune hemolytic anemia (AIHA) has been described as a rare complication of ICPis, but existing data are mostly limited to isolated case reports. Further, guidelines for the diagnosis and treatment of these patients are lacking. We describe the clinical and laboratory features of 14 patients who developed ICPi-associated AIHA. Methods: We contacted hematology departments at 18 academic medical centers across the U.S. to inquire about potential cases of ICPi-associated AIHA. Nine centers contributed a total of 14 cases to the current series. We defined AIHA as an abrupt decrease in hemoglobin ≥2g/dL, the presence of at least two laboratory features of hemolysis (elevated serum lactate dehydrogenase [LDH], elevated reticulocyte percentage, low or absent serum haptoglobin, and spherocytes), and the exclusion of other causes of anemia. We collected data on demographics and comorbidities, features of AIHA, and response to treatment. We defined complete recovery (CR) and partial recovery (PR) of hemoglobin as an increase from the nadir hemoglobin to within 1 and 2 g/dL of the baseline value, respectively, in the absence of recent transfusion. Results: The clinical features of the 14 patients in our cohort with ICPi-associated AIHA are summarized in the Figure (panel A). Underlying malignancies included melanoma (n = 9), non-small cell lung cancer (n = 3), colorectal cancer (n = 1), and acute myelogenous leukemia (n = 1). Four patients had a pre-existing diagnosis of a lymphoproliferative disorder, and two of these patients were known to have a positive direct antiglobulin test (DAT) prior to initiation of ICPi. ICPis used included ipilimumab, nivolumab, a combination of ipilimumab and nivolumab, and pembrolizumab. Representative hemoglobin and LDH trends are shown in the Figure (panels B and C). The median (interquartile range [IQR]) interval from initiation of ICPis to AIHA was 55 (22-110) days. Eight patients (57%) were DAT positive: 3 were positive for both IgG and C3; 3 were positive for IgG alone; 2 were positive for C3 alone; and 1 was weakly positive on polyspecific testing. Five patients (36%) were DAT negative, and in one patient a DAT was not performed. The median (IQR) hemoglobin nadir was 6.3 (6.1-8.0) g/dL,and 11 patients (79%) required red blood cell transfusion. All patients were treated with glucocorticoids, with 3 requiring additional immunosuppressive therapy. All patients achieved a CR or PR of hemoglobin in response to treatment (CR, n = 11; PR, n =3). The median (IQR) time from the hemoglobin nadir to CR or PR was 47 (30-62) days. Seven patients (50%) experienced at least one other IRAE. Seven patients (50%) were re-challenged with ICPis, and one patient developed recurrent AIHA with re-challenge. Conclusion: ICPi-associated AIHA is a recently-described phenomenon, which will be encountered more frequently with the widespread use of ICPis. ICPi-associated AIHA shares many clinical features with other forms of AIHA; however, a unique aspect of ICPi-associated AIHA appears to be a relatively high incidence of DAT negativity (36% in our series, compared with 3-11% in other forms of AIHA). It is possible that more advanced DAT testing - i.e., "super-Coombs" - which was not performed in any of the patients in this series, would have yielded different results. Glucocorticoids appear to be an effective first-line regimen in most patients with ICPi-associated AIHA. Furthermore, we found that AIHA does not necessarily recur with ICPi re-challenge. Additional studies are needed to better understand the mechanisms underlying ICPi-associated AIHA and optimal treatment strategies. Disclosures Anagnostou: ASH Research Training Award for Fellows 2018: Research Funding; Mayo Clinic SPORE: Research Funding; Mayo Clinic Immune Monitoring Core: Research Funding; Mayo Clinic Hematology Research Division: Research Funding. Salama:BMS: Research Funding; Celldex: Research Funding; Dynavax: Research Funding; Genentech: Research Funding; Merck: Research Funding; Reata: Research Funding; Incyte: Research Funding; Immunocore: Research Funding; Array: Consultancy; Merck: Consultancy; Biocryst: Consultancy; BMS: Speakers Bureau.

AbstractImmune checkpoint inhibitors (ICPis) are a novel class of immunotherapeutic agents that have revolutionized the treatment of cancer; however, these drugs can also cause a unique spectrum of autoimmune toxicity. Autoimmune hemolytic anemia (AIHA) is a rare, but often severe, complication of ICPis. We identified 14 patients from nine institutions across the United States who developed ICPi‐AIHA. The median interval from ICPi initiation to development of AIHA was 55 days (interquartile range [IQR], 22‐110 days). Results from the direct antiglobulin test (DAT) were available for 13 of 14 patients: 8 patients (62%) had a positive DAT and 5 (38%) had a negative DAT. The median pretreatment and nadir hemoglobin concentrations were 11.8 g/dL (IQR, 10.2‐12.9 g/dL) and 6.3 g/dL (IQR, 6.1‐8.0 g/dL), respectively. Four patients (29%) had a preexisting lymphoproliferative disorder, and two (14%) had a positive DAT prior to initiation of ICPi therapy. All patients were treated with glucocorticoids, with three requiring additional immunosuppressive therapy. Complete and partial recoveries of hemoglobin were achieved in 12 (86%) and 2 (14%) patients, respectively. Seven patients (50%) were rechallenged with ICPis, and one (14%) developed recurrent AIHA. Clinical and laboratory features of ICPi‐AIHA were similar in DAT positive and negative patients. ICPi‐AIHA shares many clinical features with primary AIHA; however, a unique aspect of ICPi‐AIHA is a high incidence of DAT negativity. Glucocorticoids are an effective first‐line treatment in the majority of patients with ICPi‐AIHA, and most patients who are rechallenged with an ICPi do not appear to develop recurrence of AIHA.