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P-BCMA-101 is an autologous chimeric antigen receptor-T cell (CAR-T) therapeutic targeting BCMA and comprised of a high percentage of desirable stem cell memory T cells. P-BCMA-101 is manufactured using a novel transposon-based system called piggyBac and is designed to increase efficacy while minimizing toxicity. A phase 1/2, clinical trial is being conducted in patients with r/r MM (≥ 3 prior lines, including a proteasome inhibitor and an IMiD, or double refractory) to assess the safety and efficacy of P-BCMA-101 (NCT03288493). No pre-specified level of BCMA expression was required. Patients are apheresed to harvest T cells, P-BCMA-101 is then manufactured and administered to patients intravenously (IV) after a standard 3-day cyclophosphamide (300 mg/m2/day) / fludarabine (30 mg/m2/day) lymphodepletion regimen. As of 30Jun20, 43 patients had been treated with P-BCMA-101 (M/F 67%/33%, median age 60 years). Patients were heavily pre-treated (median of 7 prior regimens; range 3-18), with 100% having received proteasome inhibitors and IMiD, 93% daratumumab and 58% ASCT. This study was initially conducted as a dose escalation trial of single infusions of P-BCMA-101 from 0.75-15 x 106 cells/kg, preceded by standard lymphodepletion. Subsequently, exploratory cohorts with novel therapeutic strategies were evaluated. Using a modified manufacturing process, a median dose of 0.75 x 106 cells/kg were administered in cohorts including: P-BCMA-101 infusions in biweekly cycles; the addition of rituximab or lenalidomide pre- and post- lymphodepletion to prevent anti-CAR antibody development and increase T cell robustness, respectively; and single administration. The safety profile across the entire group was excellent for a CAR-T cell product which was attributed the gradual expansion of the Tscm cells (2-3 weeks to peak versus 3-7 days for most CAR-T cells). Cytokine release syndrome (CRS) was only seen in 17% of patients, with only one being grade 3 and one case of possible neurotoxicity reported (transient increase in confusion). Likewise, peak elevations of CRS markers were modest (maximum IL-6 level reported in any patient was 1631 pg/mL, orders of magnitude lower than levels frequently associated with severe CRS with CAR-T products). Only 3 patients required tocilizumab and no patients required ICU admission, safety switch activation or other aggressive measures. Based on the safety results the protocol was amended to allow fully outpatient CAR-T cell administration. There have been no patient deaths, DLTs or unexpected/off-target toxicities related to P-BCMA-101. The most common adverse events otherwise were cytopenias/infections and constitutional symptoms (≥ grade 3 neutropenia 79%, thrombocytopenia 30%, anemia 30%), as expected in CAR-T cell studies with lymphodepleting chemotherapy. Consistent with the high percentage of Tscm, circulating P-BCMA-101 cells were detected in blood by PCR, peaking at 2-3 weeks after infusion, and remaining detectable up to 1.5 years (ongoing at last follow-up). Response was seen to correlate with the Cmax and AUC of cell expansion, none of which correlated with dose administered. The overall response rate (ORR) for evaluable subjects (n=34) treated with single administration during the initial dose escalation was 57%. As there was not a definite dose response curve, but indications of better response at lower doses, additional cohorts were implemented focusing on the lower end of the dose range using product from the modified manufacturing process. Four patients were subsequently treated with cyclic administration, rituximab, lenalidomide or single administration at the lowest dose level with this manufacturing process (all treated with P-BCMA-101 within ~2 months prior to the data cut-off date), and thus far all have rapidly responded (100% ORR) and all responses are ongoing. The safety profile in these patients (including multiply infused patients) was no different than the overall population, with minimal CRS reported. In conclusion, current clinical data are consistent with preclinical findings that the novel design of P-BCMA-101 can produce significant efficacy, with remarkably low toxicity allowing for outpatient administration. Low doses appear highly efficacious and the modifications to manufacturing appear to have notably improved efficacy. Disclosures Costello: Poseida Therapeutics: Research Funding; Janssen: Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Celgene: Honoraria, Research Funding. Cohen:Seattle Genetics: Membership on an entity's Board of Directors or advisory committees; AstraZeneca: Membership on an entity's Board of Directors or advisory committees; Genentech/Roche: Membership on an entity's Board of Directors or advisory committees; GlaxoSmithKline: Membership on an entity's Board of Directors or advisory committees; Kite Pharma: Membership on an entity's Board of Directors or advisory committees; Oncopeptides: Membership on an entity's Board of Directors or advisory committees; Novartis: Other: Patents/Intellectual property licensed, Research Funding; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Research Funding; Celgene: Membership on an entity's Board of Directors or advisory committees; Takeda,: Membership on an entity's Board of Directors or advisory committees; Janssen: Membership on an entity's Board of Directors or advisory committees. Patel:Bristol Myers Squibb: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Precision Biosciences: Research Funding; Oncopeptides: Consultancy; Poseida: Research Funding; Nektar: Consultancy, Research Funding; Janssen: Consultancy, Research Funding; Cellectis: Research Funding. Berdeja:Lilly: Research Funding; BMS: Consultancy, Research Funding; Takeda: Consultancy, Research Funding; Novartis: Research Funding; Bioclinica: Consultancy; Glenmark: Research Funding; Acetylon: Research Funding; Vivolux: Research Funding; Abbvie: Research Funding; CRISPR Therapeutics: Consultancy, Research Funding; CURIS: Research Funding; Janssen: Consultancy, Research Funding; Legend: Consultancy; Bluebird: Research Funding; Karyopharm: Consultancy; Kesios: Research Funding; Teva: Research Funding; Servier: Consultancy; Amgen: Consultancy, Research Funding; Cellularity: Research Funding; Celgene: Consultancy, Research Funding; Poseida: Research Funding; Prothena: Consultancy; Kite Pharma: Consultancy; EMD Sorono: Research Funding; Genentech, Inc.: Research Funding; Constellation: Research Funding. Shah:BMS, Janssen, Bluebird Bio, Sutro Biopharma, Teneobio, Poseida, Nektar: Research Funding; GSK, Amgen, Indapta Therapeutics, Sanofi, BMS, CareDx, Kite, Karyopharm: Consultancy. Ganguly:Kadmon: Other: Ad Board; KITE Pharma: Speakers Bureau; Settle Genetics: Speakers Bureau. Abedi:BMS, Gilead Sciences: Research Funding; AbbVie, BMS, Gilead Sciences, Seattle Genetics, Takeda: Speakers Bureau. Yalamanchili:Poseida Therapeutics: Current Employment, Current equity holder in private company. Gregory:Kesios: Research Funding; Sanofi: Research Funding; Janssen: Research Funding; Celularity: Research Funding; Teva: Research Funding; Vivolux: Research Funding; Lilly: Research Funding; Constellation: Research Funding; BMS: Research Funding; Celgene: Research Funding; Novartis: Research Funding; Poseida: Research Funding; CRISP Therapeutics: Research Funding; CURIS: Research Funding; Acetylon: Research Funding; Incyte Corporation: Consultancy; Bluebird: Research Funding; Amgen: Research Funding; AbbVie: Research Funding; Takeda: Research Funding; Genentech: Research Funding; Glenmark: Research Funding; EMD Sorono: Research Funding.

INTRODUCTION An exaggerated proinflammatory response to endotoxaemia can occur in obstructive jaundice. The aims of this study were to determine the hepatic proinflammatory and anti-inflammatory cytokine response to endotoxaemia in experimental biliary obstruction and to determine the source of interleukin-6 (IL-6) using immunohistochemistry. METHODOLOGY Male Wistar rats were randomized into three groups: bile duct ligation (BDL), sham operation, and control groups. They were weighed before surgery and after 1 week. On day 8, hepatic perfusion was performed with endotoxin (Escherichia coli 0111:B4). Serial samples of blood, effluent, and influent perfusate were analyzed for proinflammatory and anti-inflammatory cytokines. Ultrastructural assessment of sections of the liver was performed. RESULTS BDL animals lost weight in the first week compared with the sham and the control animals that gained weight. Liver function tests were elevated in the BDL group. Effluent biochemistry did not reveal liver injury as a result of perfusion. Ultrastructurally, there was no evidence of liver injury, with only active Kupffer cells, preservation of liver architecture, and minimal liver injury being detected. Serum tumor necrosis factor-α was not detected in any group before perfusion; however, serum IL-6 was higher in the BDL group. Portal endotoxaemia resulted in an increase in tumor necrosis factor-α, IL-6, and IL-10 in the BDL group. Fluorescence immunohistochemistry demonstrated IL-6 in the sinusoidal spaces and the cytoplasm of Kupffer cells. CONCLUSION There is an exaggerated proinflammatory and anti-inflammatory cytokine response to portal endotoxaemia in animals with jaundice compared with the sham group.

Background Complex limb trauma often involves combined arterial and venous injury, and the resultant ischaemia–reperfusion injury (IRI) causes both local and remote organ injury. This study assessed the influence of the timing of restoration of venous drainage on IRI. Methods Male New Zealand white rabbits (n = 36) were randomized into six groups: sham operation (group 1) and unilateral hind limb arterial and venous occlusion for 1 h followed by no reflow for 2 h (group 2), arterial and venous reflow for 2 h (group 3), arterial reflow alone for 2 h (group 4), arterial reflow alone for 1 h followed by arterial and venous (delayed) reflow for a further 1 h (group 5), and pretreatment with an enteral combination antioxidant before occlusion of both artery and vein and delayed venous reflow (group 6). Plasma hydroperoxide (HPO) and glutathione peroxidase concentration, hind limb skeletal muscle and lung tissue wet: dry weight ratios and myeloperoxidase (MPO) concentration were measured. Results The plasma HPO level in the femoral vein effluent was significantly greater after delayed venous reflow (mean(s.e.m.) 2·02(0·54) μmol/l) than in control animals (0·98(0·10) μmol/l) (P < 0·05). There was also a significantly greater tissue wet: dry weight ratio after delayed venous reflow than in controls, in skeletal muscle (mean(s.e.m.) 6·89(0·14) versus 5·34(0·54); P < 0·05) and lung (9·20(1·14) versus 7·23(0·38); P < 0·05) tissue. Lung tissue MPO activity was significantly greater after delayed venous reflow compared with controls (3·20(0·28) versus 1·86(0·14) units/g; P < 0·005), and also in comparison to simultaneous arterial and venous reflow (2·40(0·24) units/g; P < 0·05). In the antioxidant pretreatment group there was no significant increase in plasma HPO concentration, tissue MPO level or tissue wet: dry weight ratio compared with the control group. Conclusion In combined major arterial and venous injury of the limb, delayed restoration of venous drainage leads to significantly greater local skeletal muscle injury and remote neutrophil-mediated lung injury. These results support the clinical rationale for early restoration not only of arterial inflow but also venous drainage by means of intraluminal shunts.

Background Sepsis and endotoxaemia occur frequently in biliary obstruction. Impaired Kupffer cell endocytosis is implicated in these events. Tumour necrosis factor and interleukin 6, secreted by Kupffer cells, are important mediators of sepsis. Kupffer cell clearance of endotoxin and secretion of cytokines in experimental obstructive jaundice were investigated. Methods Wistar rats were randomized to bile duct ligation, sham operation or control. Groups (n = 8) were studied 1 and 3 weeks after operation. Kupffer cell function was assessed using in situ hepatic perfusion. Results Clearance of endotoxin was significantly depressed 1 week (median (interquartile range) 20·3 (10·5–27·1) per cent) and 3 weeks (22·1 (20·2–23·2) per cent) after bile duct ligation compared with that in respective sham animals (35·5 (29·9–41·6) and 40·9 (37·7–47·0) per cent) and controls (39·5 (37·3–46·8) per cent). Secretion of tumour necrosis factor was significantly greater 1 week (1113·7 (706·5–1436·8) pg/ml) and 3 weeks (1118·2 (775·7–1484·1) pg/ml) following bile duct ligation compared with that in respective sham animals (114·3 (0–178·5) and 107·6 (63·7–166·4) pg/ml) and controls (0 (0–20·7) pg/ml). Interleukin 6 was not secreted by sham or control animals but was present in the perfusate from jaundiced animals at 1 and 3 weeks (52·5 (9·9–89·5) and 66·2 (60·2–193·1) pg/ml). Conclusion These data demonstrate simultaneous impairment of Kupffer cell clearance of endotoxin and increased secretion of proinflammatory cytokines in experimental obstructive jaundice. These diverse responses may contribute to the development of sepsis-related complications in biliary obstruction.

Background It has been suggested that bowel permeability is altered following abdominal aortic aneurysm surgery. The effect of ischaemia-reperfusion injury to the lower limb on the morphological structure, neutrophil infiltration and permeability of the bowel was investigated. Methods Histological assessment of the bowel was undertaken in five groups of Wistar rats: control, 3 h of bilateral hind limb ischaemia and 3 h of bilateral hind limb ischaemia followed by 1, 2 or 3 h of reperfusion. Using an everted gut sac model and 14 C-labelled polyethylene glycol, the effect of ischaemia-reperfusion on small bowel permeability was studied. Results The small bowel showed a significant decrease in mucosal thickness, villus height and crypt depth in animals subjected to ischaemia followed by 2-hr reperfusion (mean(s.e.m.) 420(15), 217(9) and 163(6) μm respectively) compared with controls (481(11), 245(6) and 195(6) μm) (P

In 30 patients undergoing elective repair of abdominal aortic aneurysm the intramucosal pH (pHi) of the sigmoid colon was measured. Blood for endotoxin assay was taken at intervals before, during and after surgery. Daily measurements were made of liver transaminase activity and of arterial partial pressure of oxygen (PaO2). The mean(s.e.m.) peak systemic endotoxin concentration in those who developed intramucosal acidosis (pHi below 7·00) was 90(14) pg/ml, compared with 42(5) pg/ml in those who did not (P < 0·01). In the 14 patients whose pHi fell below 7·00, the mean(s.e.m.) postoperative rise in aspartate transaminase activity was 346(74) per cent, compared with 181(20) per cent in those whose pHi remained above this level (P < 0·05). The mean(s.e.m.) postoperative ratio of PaO2, to the fraction of inspired oxygen was 177(11) mmHg in those with intramucosal acidosis, compared with 260(24) mmHg in those whose pHi remained above 7·00 (P < 0·01). These results demonstrate a relationship between bowel ischaemia, endotoxaemia and organ impairment following elective aneurysm repair.

Effects of the nonsteroidal anti-inflammatory drug, diclofenac, on stimulated monocyte superoxide production were assessed directly in vitro and following treatment of patients with rheumatoid arthritis ex vivo. Diclofenac inhibited superoxide generation provoked by serum treated zymosan (STZ) and fluoride anion (F) but not by phorbol myristate acetate (PMA) in vitro. Following patient therapy, inhibition of superoxide production occurred when STZ and PMA, but not F were used as stimuli. No changes were seen in control subjects. The contrasting profiles of inhibition seen in vitro and ex vivo suggest an indirect effect on superoxide production during clinical use of the agent. These data are consistent with the hypothesis that anti-inflammatory drugs may act in rheumatoid arthritis by inhibiting phagocyte super-oxide anion production.

A survey of the incidence of monocyte esterase deficiency in 4000 inpatients (including 808 with malignant neoplastic disease) and 474 normal controls was performed using an automated esterase method. A highly significant excess of patients with malignant disease and the deficiency was evident when compared with normal controls or all other patients. Within the group of patients with malignant disease the demonstrable excess occurred in B chronic lymphocytic leukaemia, non-Hodgkin's and Hodgkin's lymphoma, and carcinoma of the gastrointestinal tract. There was also a significant excess of patients with the deficiency attending the renal unit, both among patients who had had renal transplants and those who had not. A familial incidence of monocyte esterase deficiency was found in 19 (35%) of first degree relatives of those patients in whom family studies were done. It is suggested that the reason for the increased prevalence of the anomaly in these disorders might be that the diminution of esterase activity has a role in their development.

Sepsis leads to release of reactants that play an important role in the development of multiple organ failure. The kinetics of two early mediators of the response to sepsis, tumour necrosis factor (TNF alpha) and interleukin 6 (IL-6), and their modulation with pentoxifylline (PTF), were investigated. An established and clinically relevant animal model was employed, and sepsis was induced by cecal ligation and puncture (CLP) in Wistar rats. Six hours after the operation, there was an increase in IL-6 in all animals, which declined toward normal by 18 hours. This early phase of IL-6 production was not influenced by PTF. TNF alpha and IL-6 were significantly higher in the CLP group than in the animals treated with PTF at 24 hours. The blood pressure of the CLP group at 24 hours was significantly lower than that of the shams, and this decrease was not influenced by PTF. This decline in blood pressure may have been the stimulus to TNF production and the second phase of IL-6 production, which appeared to be inhibited by PTF. Pentoxifylline appears to attenuate systemic cytokine production in this model and may have a role in the management of clinical sepsis.

This study compared mortality rates, endotoxaemia, systemic tumour necrosis factor (TNF) and interleukin (IL)-6 concentrations after continuous and intermittent hepatic ischaemia. Two groups of rats were subjected to continuous or intermittent left hepatic inflow occlusion for a total period of 120 min in each group. Intermittent ischaemia was associated with significantly lower mortality rates than continuous ischaemia (four of 20 versus 15 of 20; P = 0±0015). In a separate study, again following 120 min continuous or intermittent ischaemia, systemic blood was sampled at 0 min, 1 h, 3 h and 5 h after final clamp release for measurement of endotoxin, TNF and IL-6 concentrations. Endotoxin concentrations were significantly lower at 1 h, as were TNF and IL-6 concentrations at 3 and 5 h, after final clamp release in the group having intermittent ischaemia (P

Background It has been suggested that reperfusion of the acutely ischaemic lower limb alters gut permeability. The effect of lower limb ischaemia–reperfusion on systemic endotoxin and antiendotoxin antibody concentrations and the incidence of bacterial translocation was investigated. Methods Systemic endotoxin and antiendotoxin antibody concentrations were measured in five groups of male Wistar rats: control, after 3 h of bilateral hind limb ischaemia alone, and after 3 h of bilateral hind limb ischaemia followed by 1, 2 or 3 h of reperfusion. A second experiment examined translocation of indigenous bacteria following 2 h of reperfusion in a similar model. Results Ischaemia followed by reperfusion for 1, 2 or 3 h caused a significant increase in plasma endotoxin concentration to mean(s.e.m.) 10·0(3·0), 44·8(19·2) and 20·2(6·2) pg/ml compared with that in control animals (2·58(0·91) pg/ml) or animals in the ischaemia alone group (1·2(0·9) pg/ml) (P < 0·05). This was associated with a significant reduction in endogenous antiendotoxin antibody (immunoglobulin (Ig) G and IgM) concentration. No significant bacterial translocation was detected in any of the groups studied. Conclusion These results demonstrate that a remote and isolated ischaemia–reperfusion injury to the lower limb, in the absence of infection or bacterial translocation, causes endotoxaemia. Further studies are needed to evaluate the role of endogenous antiendotoxin antibodies in this situation.

Background—Endotoxaemia is implicated in the pathophysiology of obstructive jaundice. The EndoCab enzyme linked immunosorbent assay (ELISA) is a novel assay which measures endogenous antibody (IgG) to the inner core region of circulating endotoxins (ACGA).Aims—To investigate the significance of endotoxaemia in biliary obstruction using the EndoCab assay and assess the specificity of the humoral response to endotoxin compared with an exogenous antigenic challenge (tetanus toxoid, TT).Methods—Three groups of adult male Wistar rats were studied: no operation, sham operation, and bile duct ligation for 21 days (BDL). In the second study, rats rats received prior immunisation with TT.Results—In the preliminary experiment, plasma ACGA was significantly increased in the BDL group (306.6 (18.3)% versus 119.9 (6.7)% and 105.2 (4.6)% in the sham and no operation groups, respectively; pConclusions—The specific rise in ACGA supports the hypothesis that endotoxin has an integral role in the pathophysiology of obstructive jaundice. The production of anticore glycolipid antibodies specifically reflects systemic endotoxaemia in this model. The EndoCab assay provides a novel, sensitive, and specific method for endotoxin detection.

The efficacy of lactulose as an antiendotoxin was studied and the effect of lactulose or colistin on faecal flora was investigated in a hapten-induced rat model of colitis. Enteral administration of lactulose to rats with colitis was associated with a significant reduction in the systemic concentration of endotoxin (median (range) 5.4 (0–19.9) versus 23.7 (0–145.0) pg/ml in colitic rats treated with water; 4.6 (0–10.8) pg/ml in healthy animals). Enteral administration of colistin significantly reduced the faecal count of aerobic Gram-negative bacilli (median (range) 2.84 (1.40–8.43) versus 8.26 (4.50–10.40) log10 colony-forming units per g faeces after treatment with water) but not the faecal load of endotoxin. Patients with inflammatory bowel disease may benefit from enteral treatment with lactulose to prevent systemic endotoxaemia and/or with colistin to modify enteric bacteria.

The intestinal mucosa protects the body from a large reservoir of intraluminal pathogenic bacteria and endotoxins. This mucosal barrier is disrupted by the inflammation and ulceration of inflammatory bowel disease and may permit the absorption of toxic bacterial products. Systemic endotoxaemia has been demonstrated in ulcerative colitis and Crohn's disease and correlates with the extent and activity of disease. In this study the efficacy of absorbents as antiendotoxin agents in a hapten induced rat model of colitis is investigated. Induction of colitis was associated with systemic endotoxaemia. Enteral administration of terra fullonica and kaolin, but not of charcoal, significantly reduced systemic endotoxaemia (terra fullonica 4.2 (1.40) pg/ml; kaolin 5.29 (1.86) pg/ml; charcoal 32.7 (16.6) pg/ml; water 39.8 (12.6) pg/ml). Data expressed as mean (SE). With increasing severity of colitis, there was a decreasing ability of adsorbent therapy (terra fullonica) to control systemic endotoxaemia. Enteral administration of adsorbents controls gut derived systemic endotoxaemia in experimental colitis in animals and may be a useful antiendotoxin treatment in patients with inflammatory bowel disease.

Deficiency of the monocyte ectoenzyme non-specific esterase is described in a heredofamilial pattern in four patients with rheumatoid arthritis. No association with HLA status or rheumatoid factor seropositivity was found.

• Systemic endotoxemia consistently occurs in jaundiced patients undergoing surgery. Kupffer cell dysfunction is implicated in the development of endotoxemia and its postoperative complications. A novel in situ single-pass hepatic perfusion technique using a fluorescein isothiocyanate-labeled latex probe was developed for measuring Kupffer cell clearance capacity and was applied in an animal model of biliary obstruction. Control rats and rats jaundiced for 1, 2, 3, and 4 weeks' duration were studied. Kupffer cell clearance capacity, plasma bilirubin, endotoxin, and anti-core glycolipid concentrations were measured. Maximal hyperbilirubinemia preceded reduced Kupffer cell clearance capacity. Rats jaundiced for greater than 2 weeks had a significantly decreased Kupffer cell clearance capacity but significantly higher endotoxin and anticore glycolipid concentrations. Anticore glycolipid concentrations correlated strongly with systemic endotoxemia and both were inversely correlated with duration of jaundice. Impairment of Kupffer cell clearance capacity may contribute to endotoxemia associated with cholestasis. (Arch Surg. 1993;128:200-205)