The massive tissue factor stimulus results in excess intravascular thrombin, which overcomes the anticoagulant systems and leads to thrombosis. Because of consumption of coagulation factors and platelets, DIC also has a hemorrhagic phase. Treatment of the bleeding patient with DIC is supportive with the use of blood components.

102 Background: MAGE-A4 is a cancer/testis antigen with expression in many solid tumors promoting cell growth by preventing cell cycle arrest and apoptosis. This study (NCT03132922) evaluated safety and efficacy of SPEAR T-cells directed against the MAGE-A4 peptide expressed in 9 tumor types. Methods: This Phase I dose-escalation, expansion trial evaluated patients (pt) who were HLA-A*02 positive with advanced cancers that expressed the MAGE-A4 protein. Autologous T-cells from eligible patients were isolated, transduced with a lentiviral vector containing the MAGE-A4c1032 TCR, and expanded. Prior to ADP-A2M4 infusion, pts received a lymphodepletion regimen of cyclophosphamide and fludarabine. Cohorts 1, 2, 3, and expansion were to receive transduced cell doses of up to: 0.12 × 109, 1.2 × 109, 6 × 109, and 10 x 109, respectively. Results: As of 23 October 2019, 9 pts were treated in dose escalation with no DLTs; 25 pts were treated in expansion. Median age was 56.5 yr (range: 31-78). All pts received prior chemotherapy. Most common ( > 30%) AEs ≥Grade 3 were lymphopenia, leukopenia, neutropenia, anemia, thrombocytopenia, and febrile neutropenia. Two pts had trial-related deaths (aplastic anemia and CVA) leading to modification of the lymphodepletion regimen and eligibility criteria. In Cohort 3/expansion (28 pts), Best Overall Response was PR (7), SD (11), PD (5), non-evaluable (5). All PRs, at the time of data cut-off, were in patients with synovial sarcoma. Transduced T-cells were detectable in all patients. Tumor infiltration of SPEAR T-cells was detectable in several cohort 3/expansion pts. Conclusions: The Phase I single agent ADP-A2M4 trial will complete enrollment shortly and updated data will be presented. ADP-A2M4 shows promising efficacy and a manageable safety profile at a dose range of 1.2 – 10 × 109. Clinical activity in various tumors has led to a separate on-going low dose radiation sub-study of this trial, a Phase II trial in sarcoma (SPEARHEAD-1, NCT04044768), and a Phase I trial (SURPASS, NCT04044859) with ADP-A2M4CD8, a next-generation SPEAR T-cell targeting MAGE-A4. Clinical trial information: NCT03132922.

Affinity-optimized T cell receptors can enhance the potency of adoptive T cell therapy. Afamitresgene autoleucel (afami-cel) is a human leukocyte antigen-restricted autologous T cell therapy targeting melanoma-associated antigen A4 (MAGE-A4), a cancer/testis antigen expressed at varying levels in multiple solid tumors. We conducted a multicenter, dose-escalation, phase 1 trial in patients with relapsed/refractory metastatic solid tumors expressing MAGE-A4, including synovial sarcoma (SS), ovarian cancer and head and neck cancer (NCT03132922). The primary endpoint was safety, and the secondary efficacy endpoints included overall response rate (ORR) and duration of response. All patients (N = 38, nine tumor types) experienced Grade ≥3 hematologic toxicities; 55% of patients (90% Grade ≤2) experienced cytokine release syndrome. ORR (all partial response) was 24% (9/38), 7/16 (44%) for SS and 2/22 (9%) for all other cancers. Median duration of response was 25.6 weeks (95% confidence interval (CI): 12.286, not reached) and 28.1 weeks (95% CI: 12.286, not reached) overall and for SS, respectively. Exploratory analyses showed that afami-cel infiltrates tumors, has an interferon-γ-driven mechanism of action and triggers adaptive immune responses. In addition, afami-cel has an acceptable benefit–risk profile, with early and durable responses, especially in patients with metastatic SS. Although the small trial size limits conclusions that can be drawn, the results warrant further testing in larger studies.

Live antibody-coated Trypanosoma brucei parasites remove variable surface glycoprotein (VSG)-antibody complexes from their surface upon warming to 37 degrees C and evade antibody-activated complement lysis by both protein synthesis-dependent and protein synthesis-independent mechanisms. The protein synthesis-dependent process follows antibody-mediated trypanosome agglutination, whereas the protein synthesis-independent mechanism can occur in the absence of trypanosome agglutination. The latter process leads to a more rapid elimination of complement-fixing VSG-antibody complexes.

Background Transfusion of packed red blood cells (RBCs) produces a myriad of immunologic derangements, from suppressive to stimulatory. Proliferation of human T cells is suppressed in vitro after exposure to processed red blood cells (PRBCs). We hypothesized that this effect would be mitigated by using fresh RBCs. We also hypothesized that this suppressive effect was a generalized effect on lymphocyte proliferation and would be observed in both CD4+ and CD8+ T-cell subpopulations as well as B cells. Materials and methods We isolated human T cells from donor peripheral blood mononuclear cells and exposed them to either blood bank PRBCs or fresh RBCs from volunteer donors and stimulated them with anti-CD3/anti-CD28. Human B cells were stimulated with lipopolysaccharide and exposed to PRBCs or fresh RBCs. We measured proliferation of B cells by thymidine incorporation assays. We also treated RBCs with citrate-phosphate-dextrose (CPD) at different time points before culture them with stimulated T cells to determine the role of this common RBC storage solution in lymphocyte proliferation. Results In vitro proliferation of CD4+ and CD8+ T cells was suppressed by blood bank RBCs. This suppression is eliminated when fresh RBCs were used. The B cells showed inhibition of proliferation when exposed to similar conditions, which appeared to be consistent over serial dilutions. Fresh RBCs exposed to CPD did not appear suppressive in the first 6 h after exposure. Conclusions T-cell and B-cell proliferation inhibition by blood banked RBCs suggests a generalized effect of RBCs on cellular proliferation. The lack of suppression by fresh RBCs further suggests that something involved in blood banking alters RBC properties such that they attain a suppressive phenotype. One such blood banking component, CPD, does not appear to affect this suppressive phenotype within the first 6 h.