Promising clinical results have been achieved with monoclonal antibodies (mAbs) such as ipilimumab and tremelimumab that block cytotoxic T lymphocyte-associated antigen-4 (CTLA-4, CD152). However, systemic administration of these agents also has the potential for severe immune-related adverse events. Thus, local production might allow higher concentrations at the target while reducing systemic side effects. We generated a transductionally and transcriptionally targeted oncolytic adenovirus Ad5/3-D24aCTLA4 expressing complete human mAb specific for CTLA-4 and tested it in vitro, in vivo and in peripheral blood mononuclear cells (PBMCs) of normal donors and patients with advanced solid tumors. mAb expression was confirmed by western blotting and immunohistochemistry. Biological functionality was determined in a T-cell line and in PBMCs from cancer patients. T cells of patients, but not those of healthy donors, were activated by an anti-CTLA4mAb produced by Ad5/3-D24aCTLA4. In addition to immunological effects, a direct anti-CTLA-4-mediated pro-apoptotic effect was observed in vitro and in vivo. Local production resulted in 43-fold higher (Po0.05) tumor versus plasma anti-CTLA4mAb concentration. Plasma levels in mice remained below what has been reported safe in humans. Replication-competent Ad5/3-D24aCTLA4 resulted in 81-fold higher (Po0.05) tumor mAb levels as compared with a replication-deficient control. This is the first report of an oncolytic adenovirus producing a full-length human mAb. High mAb concentrations were seen at tumors with lower systemic levels. Stimulation of T cells of cancer patients by Ad5/3-D24aCTLA4 suggests feasibility of testing the approach in clinical trials.

Context.-The clinical introduction of new oral anticoagulants (NOACs) has stimulated the development of tests to quantify the effects of these drugs and manage complications associated with their use. Until recently, the only treatment choices for the prevention of venous thromboembolism in orthopedic surgical patients, as well as for stroke and systemic embolism in patients with atrial fibrillation, were vitamin K antagonists, antiplatelet drugs, and unfractionated and low-molecular-weight heparins. With the approval of NOACs, treatment options and consequent diagnostic challenges have expanded.Objective.-To study the utility of thromboelastography (TEG) in monitoring and differentiating between 2 currently approved classes of NOACs, direct thrombin inhibitors (dabigatran) and factor Xa inhibitors (rivaroxaban and apixaban).Design.-Blood samples from healthy volunteers were spiked with each NOAC in both the presence and absence of ecarin, and the effects on TEG were evaluated.Results.-Both the kaolin test reaction time (R time) and the time to maximum rate of thrombus generation were prolonged versus control samples and demonstrated a dose response for apixaban (R time within the normal range) and dabigatran. The RapidTEG activated clotting time test allowed the creation of a dose-response curve for all 3 NOACs. In the presence of anti-Xa inhibitors, the ecarin test promoted significant shortening of kaolin R times to the hypercoagulable range, while in the presence of the direct thrombin inhibitor only small and dose-proportional R time shortening was observed.Conclusions.-The RapidTEG activated clotting time test and the kaolin test appear to be capable of detecting and monitoring NOACs. The ecarin test may be used to differentiate between Xa inhibitors and direct thrombin inhibitors. Therefore, TEG may be a valuable tool to investigate hemostasis and the effectiveness of reversal strategies for patients receiving NOACs.

Coronavirus disease 2019 (COVID-19)-associated coagulopathy (CAC), characterized by hypercoagulability and an increased risk of thrombotic complications, is an important consideration in the management of patients with COVID-19. As COVID-19 is a new disease, no standard of care for the diagnosis or management of its associated coagulopathy is yet established. Whole blood viscoelastic tests, such as thromboelastography (TEG® hemostasis analyzer), analyze whole blood to provide a complete overview of the coagulation status. We conducted a systematic review of thromboelastography for management of patients with COVID-19, using MEDLINE (PubMed) and Cochrane databases. TEG® parameter measurements and clinical outcomes data were extracted for analysis. Our review found 15 publications, with overall results showing thromboelastography can identify and assess a hypercoagulable state in patients with COVID-19. Furthermore, utilization of thromboelastography in this patient population was shown to predict thrombotic complications. The benefits of thromboelastography presented here, in addition to advantages compared with laboratory coagulation tests, position thromboelastography as an important opportunity for optimizing diagnosis of CAC and improving patient management in COVID-19. Given that the benefits of thromboelastography have already been demonstrated in several other clinical applications, we anticipate that clinical data from future studies in patients with COVID-19 will further elucidate the optimal use of thromboelastography in this patient population.