Safety and activity of ibrutinib in combination with durvalumab in patients with relapsed or refractory follicular lymphoma or diffuse large B-cell lymphoma.

This phase 1b/2, multicenter, open-label study evaluated ibrutinib plus durvalumab in relapsed/refractory follicular lymphoma (FL) or diffuse large B-cell lymphoma (DLBCL). Patients were treated with once-daily ibrutinib 560 mg plus durvalumab 10 mg/kg every 2 weeks in 28-day cycles in phase 1b without dose-limiting toxicities, confirming the phase 2 dosing. Sixty-one patients with FL (n = 27), germinal center B-cell (GCB) DLBCL (n = 16), non-GCB DLBCL (n = 16), and unspecified DLBCL (n = 2) were treated. Overall response rate (ORR) was 25% in all patients, 26% in patients with FL, 13% in patients with GCB DLBCL, and 38% in patients with non-GCB DLBCL. Overall, median progression-free survival was 4.6 months and median overall survival was 18.1 months; both were longer in patients with FL than in patients with DLBCL. The most frequent treatment-emergent adverse events (AEs) in patients with FL and DLBCL, respectively, were diarrhea (16 [59%]; 16 [47%]), fatigue (12 [44%]; 16 [47%]), nausea (9 [33%]; 12 [35%]), peripheral edema (7 [26%]; 13 [38%]), decreased appetite (8 [30%]; 11 [32%]), neutropenia (6 [22%]; 11 [32%]), and vomiting (5 [19%]; 12 [35%]). Investigator-defined immune-related AEs were reported in 12/61 (20%) patients. Correlative analyses were conducted but did not identify any conclusive biomarkers of response. In FL, GCB DLBCL, and non-GCB DLBCL, ibrutinib plus durvalumab demonstrated similar activity to single-agent ibrutinib with the added toxicity of the PD-L1 blockade; the combination resulted in a safety profile generally consistent with those known for each individual agent.

Macrophage heterogeneity and cholesterol homeostasis: classically-activated macrophages are associated with reduced cholesterol accumulation following treatment with oxidized LDL.

Macrophages are centrally involved during atherosclerosis development and are the predominant cell type that accumulates cholesterol in the plaque. Macrophages however, are heterogeneous in nature reflecting a variety of microenvironments and different phenotypes may be more prone to contribute towards atherosclerosis progression. Using primary human monocyte-derived macrophages, we sought to evaluate one aspect of atherogenic potential of different macrophage phenotypes by determining their propensity to associate with and accumulate oxidized low density lipoprotein (oxLDL). Classically-activated macrophages treated simultaneously with interferon γ (IFNγ) and tumor necrosis factor α (TNFα) associated with less oxLDL and accumulated less cholesterol compared to untreated controls. The combined treatment of IFNγ and TNFα reduced the mRNA expression of CD36 and the expression of both cell surface CD36 and macrophage scavenger receptor 1 (MSR1) protein. Under oxLDL loaded conditions, IFNγ and TNFα did not reduce macrophage protein expression of the transcription factor peroxisome proliferator-actived receptor γ (PPARγ) which is known to positively regulate CD36 expression. However, macrophages treated with IFNγ attenuated the ability of the PPARγ-specific agonist rosiglitazone from upregulating cell surface CD36 protein expression. Our results demonstrate that the observed reduction of cholesterol accumulation in macrophages treated with IFNγ and TNFα following oxLDL treatment was due at least in part to reduced cell surface CD36 and MSR1 protein expression.

MRM-based multiplexed quantitation of 67 putative cardiovascular disease biomarkers in human plasma.

A highly-multiplexed MRM-based assay for determination of cardiovascular disease (CVD) status and disease classification has been developed for clinical research. A high-flow system using ultra-high performance LC and an Agilent 6490 triple quadrupole mass spectrometer, equipped with an ion funnel, provided ease of use and increased the robustness of the assay. The assay uses 135 stable isotope-labeled peptide standards for the quantitation of 67 putative biomarkers of CVD in tryptic digests of whole plasma in a 30-min assay. Eighty-five analyses of the same sample showed no loss of sensitivity (<20% CV for 134/135 peptides) and no loss of retention time accuracy (<0.5% CV for all peptides). The maximum linear dynamic range of the MRM assays ranged from 10(3) -10(5) for 106 of the assays. Excellent linear responses (r >0.98) were obtained for 117 of the 135 peptide targets with attomole level limits of quantitation (<20% CV and accuracy 80-120%) for 81 of the 135 peptides. The assay presented in this study is easy to use, robust, sensitive, and has high-throughput capabilities through short analysis time and complete automated sample preparation. It is therefore well suited for CVD biomarker validation and discovery in plasma.

Combined polymorphisms in oxidative stress genes predict coronary artery disease and oxidative stress in coronary angiography patients.

Oxidative stress has been implicated in all stages of atherosclerosis, but how inherited variations in oxidative stress genes influence the severity of cardiovascular disease is not known. We tested associations between polymorphisms in candidate oxidative stress genes, plasma oxidative stress biomarkers, and cardiovascular mortality in an angiography cohort. Single nucleotide polymorphisms (SNPs) across 15 genes were selected by linkage disequilibrium tagging. Genotyping was performed using customized arrayed primer extension micro-arrays, with automated genotype calling methods. Effects of SNPs and haplotypes on plasma oxidative stress and coronary artery disease (CAD) were estimated using a stochastic estimation maximization algorithm. Proportionate hazards analyses were used to determine effects of single and combined genetic markers on cardiovascular mortality risk, and on the following oxidative stress biomarkers: myeloperoxidase (MPO), nitrotyrosine, oxidized low-density lipoprotein, and antioxidant capacity. Oxidative stress gene SNPs associated with CAD were combined into an oxidative stress risk allele score, which predicted disease presence (1.5-fold risk increase per allele, P < 0.001). Combined risk alleles were also associated with elevated plasma MPO (P < 0.003), an oxidative stress biomarker that predicts cardiovascular mortality. Genetic markers that represent lifetime oxidative stress burden may implicate specific oxidative stress pathways in the pathogenesis of atherosclerosis, and offer therapeutic opportunities.

Naturally occurring human plasminogen, like genetically related apolipoprotein(a), contains oxidized phosphatidylcholine adducts.

Human apolipoprotein(a) (apo(a)), synthesized in the liver, contains oxidized phosphatidylcholine (oxPtdPC) adducts probably generated at the hepatic site. Since plasminogen (Plg), also synthesized in the liver, is genetically related and structurally homologous to apo(a), we wanted to determine whether it contains oxPtdPCs and their location. We used Plg isolated from fresh or frozen normal human plasma and several commercial preparations. Some were freed of non-covalently bound lipids by organic solvent extraction. By immunoblot analyses, all products reacted against T15, a natural IgM monoclonal antibody specific for phosphorylcholine -containing oxidized phospholipids (ox-PLs). This immunoreactivity was retained in urokinase type plasminogen activator -generated plasmin and was abrogated in Plg previously digested with lipoprotein-associated phospholipase A(2) (Lp-PLA(2)), a reaction that generated predominantly C16:0 lysophosphatidylcholine species as determined by mass spectrometry. Lyso derivatives were also generated upon the cleavage by Lp-PLA2 of a model ox-PL chemically linked to a lysine-containing pentapeptide. From inorganic phosphorous analyses, we found 2 mol of oxPtdPC/mole of Plg distributed between the kringles 1-4 and mini-Plg domain. OxPtdPCs were also present in the Plg isolated from the serum-free medium of cultured human HepG2 cells. In conclusion, our results provide strong evidence that naturally occurring Plg contains oxPtdPC probably linked by a Schiff base and also suggest that the linkage occurs at the hepatic site. Given the emerging evidence for the cardiovascular pathogenicity of oxPtdPCs, we speculate that they may impart athero-thrombogenic properties to Plg under inflammatory conditions.

Lipoprotein-associated phospholipase A2 decreases oxidized lipoprotein cellular association by human macrophages and hepatocytes.

We investigated whether the presence of endogenous or exogenous lipoprotein-associated phospholipase A2 (Lp-PLA2) can modify the cellular association of oxidized low density lipoprotein (oxLDL) and oxidized lipoprotein(a) (oxLp(a)) by human monocyte-derived macrophages (MDM) and hepatocytes (HepG2). Purified recombinant Lp-PLA2 was used as a source of exogenous enzyme whereas Pefabloc (serine esterase inhibitor) was used to inhibit the endogenous Lp-PLA2 activity associated with isolated lipoproteins. Cellular association studies were performed with DiI-labeled oxLDL or oxLp(a) and human monocyte-derived macrophages and HepG2 cells. Active Lp-PLA2 decreased the cellular association of oxLDL and oxLp(a) in macrophages and HepG2 cells by approximately 30-40%, whereas the inactive enzyme did not significantly change oxidized lipoprotein cellular association by either cell type. OxLDL pretreated by Pefabloc increased oxLDL cellular association by MDM and HepG2 cells compared to untreated oxLDL. Therefore, unlike some lipases, Lp-PLA2 did not appear to have any catalytic independent function in oxLDL cellular association. To assess whether the reduced cellular association mediated by Lp-PLA2 was due to the hydrolysis of oxidized phosphatidylcholine (oxPC), we measured the concentration of lysophosphatidylcholine (lysoPC) in lipoprotein fractions after Lp-PLA2 treatment. LysoPC was increased by 20% (0.4 microM) and 87% (0.7 microM) by active Lp-PLA2 compared to inactive Lp-PLA2 for oxLDL and Lp(a), respectively. LysoPC at higher concentration dose-dependently increased the cellular association of oxLDL and oxLp(a) in MDM and HepG2 cells. We conclude that Lp-PLA2 mediates a decrease in oxidized lipoprotein cellular association in human macrophages and HepG2 cells by reducing the concentration of oxPC within these lipoproteins.

High Intensity Interval Training Leads to Similar Inflammatory Activation as Seen With Traditional Training in Chronic Heart Failure.

BACKGROUND: Inflammatory activation has been associated with the severity and progression of chronic heart failure (CHF). Although cardiac rehabilitation is an important therapy, acute bouts of exercise may lead to increases in pro-inflammatory cytokines with exercise intensity mediating these changes. OBJECTIVE: To evaluate the acute inflammatory response in patients living with CHF during a randomized trial following Steady State (SS) or High Intensity Interval (HIIT) training. METHODS: Patients living with CHF (n = 14) were stratified (for body mass and aerobic power) and randomized into SS and HIIT cycle exercise. The HIIT exercise training involved 2 min work:recovery phases at 90:40% heart rate reserve. The SS exercise training involved continuous exercise at 65% of heart rate reserve (matched total work). Acute inflammatory markers were evaluated (via ELISA) at baseline, immediately following the bout, and at 6, 24, and 48 h post-exercise. RESULTS: There was limited differences in the changes in inflammatory biomarkers across time between the HIIT and SS groups. Both groups experienced a significant (p < 0.05) change in Interleukin-6 immediately post-exercise. CONCLUSIONS: A single bout of HIIT or SS does not result in excessive inflammatory activation in CHF patients. Acute HIIT and SS result in similar changes in inflammatory markers. These findings have important implications for exercise training and rehabilitation programs in persons living with CHF.

Endothelial lipase promotes apolipoprotein AI-mediated cholesterol efflux in THP-1 macrophages.

OBJECTIVE: Endothelial lipase (EL) is expressed by macrophages within atherosclerotic lesions. We investigated the influence of EL expression on cholesterol efflux in macrophages. METHODS AND RESULTS: The present study used lentivirus to introduce either EL shRNA for loss-of-function studies or EL cDNA for gain-of-function studies to investigate the role of EL in apoAI-mediated cholesterol efflux. ApoAI-mediated cholesterol efflux was decreased after EL suppression, but increased with EL overexpression in free cholesterol labeled and acLDL loaded THP-1 macrophages. Similar findings were observed in THP-1 macrophages after exogenous EL addition and in transfected 293 cells. EL-related apoAI-mediated cholesterol efflux decreased after treatment with heparin or catalytic inactivation (S149A mutation or tetrahydrolipstatin) alone, and completely inhibited in combination. Furthermore, EL expression did not change ABCA1 expression, but was positively correlated with apoAI binding to macrophages and 293 cells. This effect was mitigated after heparin treatment but not influenced by catalytic inactivation via tetrahydrolipstatin or the S149A mutation. Moreover, EL expression was positively associated with lysophosphatidylcholine production and inversely with phosphatidylcholine, phosphatidylethanolamine, and sphingomyelin levels. Lysophosphatidylcholine treatment dose-dependently stimulated apoAI-mediated cholesterol efflux in THP-1 macrophages. CONCLUSIONS: EL appears to promote apoAI-mediated cholesterol efflux through catalytic and noncatalytic-dependent mechanisms.

Multiplexed LC-ESI-MRM-MS-based Assay for Identification of Coronary Artery Disease Biomarkers in Human Plasma.

PURPOSE: A highly-multiplexed LC-ESI-multiple reaction monitoring-MS-based assay is developed for the identification of coronary artery disease (CAD) biomarkers in human plasma. EXPERIMENTAL DESIGN: The assay is used to measure 107 stable isotope labeled peptide standards and native peptides from 64 putative biomarkers of cardiovascular diseases in tryptic digests of plasma from subjects with (n = 70) and without (n = 45) angiographic evidence of CAD and no subsequent cardiovascular mortality during follow-up. RESULTS: Extensive computational and statistical analysis reveals six plasma proteins associated with CAD, namely apolipoprotein CII, C reactive protein, CD5 antigen-like, fibronectin, inter alpha trypsin inhibitor heavy chain H1, and protein S. The identified proteins are combined into a LASSO-logistic score with high classification performance (cross-validated area under the curve = 0.74). When combined with a separate score computed from markers currently used in the clinic with similar performance, the area under the receiver operating curve increases to 0.84. Similar results are observed in an independent set of subjects (n = 87). CONCLUSIONS AND CLINICAL RELEVANCE: If externally validated, the assay and identified biomarkers can improve CAD risk stratification.

Safety, tolerability, and pharmacokinetics of anti-EGFRvIII antibody-drug conjugate AMG 595 in patients with recurrent malignant glioma expressing EGFRvIII.

PURPOSE: Epidermal growth factor receptor variant III (EGFRvIII) is expressed in a significant percentage of primary and recurrent glioblastoma (GBM), a common malignant primary brain tumor in adults. AMG 595 is an antibody-drug conjugate comprising a fully human, anti-EGFRvIII monoclonal antibody linked to DM1. The study goals were to assess safety, tolerability, and pharmacokinetics of AMG 595 in GBM. METHODS: In this phase 1, first-in-human, open-label, sequential-dose, exploration study, adults with recurrent GBM received AMG 595 once every 3 weeks (Q3W) according to incremental dosing cohorts (0.5-3.0 mg/kg). Primary endpoints were to assess safety, the incidence of dose-limiting toxicities (DLTs), objective response (per Macdonald criteria), evaluate pharmacokinetics, and estimate the maximum tolerated dose (MTD). RESULTS: Of 382 patients screened, 32 were enrolled and received ≥ 1 dose of AMG 595. Ten patients experienced 18 DLTs (all grade 4 thrombocytopenia), and the MTD was 2.0 mg/kg. Twenty-eight patients (88%) experienced ≥ 1 treatment-related adverse event (AE); the most common AEs were thrombocytopenia (50%) and fatigue (25%). Grade ≥ 3 treatment-related AEs occurred in 17 patients (53%); 11 (34%) had serious treatment-emergent AEs, and none were considered treatment related. Pharmacokinetic profiles indicated low levels of circulating unconjugated antibody and cytotoxin, dose-proportional increases in plasma exposures for the conjugated antibody over the studied range, and less than twofold accumulation following multiple Q3W dosing. Two patients (6%) had partial responses; 15 (47%) had stable disease. CONCLUSIONS: AMG 595 exhibited favorable pharmacokinetics and is a unique therapy with possible benefit for some patients with EGFRvIII-mutated GBM with limited therapeutic options.

Modifications in low-density lipoprotein receptor expression affects Cyclosporin A cellular uptake and cytotoxicity.

The purpose of this study was to test the effect of modulating the expression of the human low-density lipoprotein receptor (LDLr) in human embryonic kidney (293T) cells on Cyclosporin A (CsA) cellular uptake and CsA-mediated cytotoxicity. LDLr expression was modulated using RNA interference (RNAi) and an LDLr overexpression plasmid. One of the small-interfering RNA (siRNA) constructs, LDLr-792, showed a 60% decrease in LDLr protein expression. The downregulation effect was specific as transfection with an annexin V (AxV) siRNA construct did not decrease LDLr expression levels. AxV and ABCA1 expression levels were not affected in the cells transfected with LDLr-792 (LDLr(LOW) cells) compared to the controls. At a functional level, fluorescent low-density lipoprotein (LDL) (DiI-LDL) internalization in the LDLr(LOW) cells was decreased (30%) compared to control cells. We tested the dose-dependent cytotoxicity induced by CsA using a respiration assay. We found a decrease in CsA-mediated cytotoxicity in the range of CsA doses studied (1-10 microg/mL) in the LDLr(LOW) cells compared to the pSHAG-transfected cells, reaching a statistical significance at 10 microg/mL CsA. At higher CsA doses we found a significant decrease in LDLr expression. When the control and LDLr(LOW) cells were treated with another cytotoxic drug, gentamycin, there was no difference in the cell viability, suggesting that this effect is specific for CsA. We confirmed the association of LDLr expression levels with CsA uptake by overexpressing the LDLr. The LDLr overexpressing cells showed an enhanced uptake of radiolabelled CsA. Taken together these results suggest that CsA internalization and cytotoxicity are affected by the LDL receptor expression levels.

Cyclosporine A and Rapamycin induce in vitro cholesteryl ester transfer protein activity, and suppress lipoprotein lipase activity in human plasma.

PURPOSE: Cyclosporine A (CsA), Rapamycin (RAPA), Tacrolimus (FK-506) and Mycophenolate mofetil (MMF) are immunosuppressants that are widely used in solid organ transplant patients. However, some of these drugs have been reported to cause dyslipidemia in patients. Our aim was to determine the effects of these drugs on in vitro cholesteryl ester transfer protein (CETP), hepatic lipase (HL) and lipoprotein lipase (LPL) activity within human plasma. METHODS: We measured CETP activity in human normolipidemic plasma with and without drug treatment, by measuring the incorporation of labeled cholesteryl ester into lipoproteins. To further confirm the result, we also measured recombinant CETP (rCETP) activity with and without drug treatment. We measured HL and LPL activity in post-heparin normal human plasma in the presence and absence of the drugs by measuring the release of fatty acids from radiolabeled triolein. RESULTS: We found an increase in CETP activity in human normolipidemic plasma and rCETP treated with CsA and RAPA. By contrast, CETP activity was not altered significantly in the presence of FK-506 and MMF. LPL activity in post-heparin normal human plasma was suppressed following the co-incubation with CsA, RAPA, FK-506 or MMF whereas HL activity remained unaffected. CONCLUSIONS: The increase in CETP activity and suppression in LPL activity following CsA and RAPA treatment observed in the present study may be associated with elevated LDL cholesterol levels and hypertriglyceridemia seen in patients administered these drugs.

First-in-Human Study of AMG 820, a Monoclonal Anti-Colony-Stimulating Factor 1 Receptor Antibody, in Patients with Advanced Solid Tumors.

Purpose: Binding of colony-stimulating factor 1 (CSF1) ligand to the CSF1 receptor (CSF1R) regulates survival of tumor-associated macrophages, which generally promote an immunosuppressive tumor microenvironment. AMG 820 is an investigational, fully human CSF1R antibody that inhibits binding of the ligands CSF1 and IL34 and subsequent ligand-mediated receptor activation. This first-in-human phase I study evaluated the safety, pharmacokinetics, pharmacodynamics, and antitumor activity of AMG 820.Experimental Design: Adult patients with relapsed or refractory advanced solid tumors received intravenous AMG 820 0.5 mg/kg once weekly or 1.5 to 20 mg/kg every 2 weeks until disease progression, adverse event (AE), or consent withdrawal.Results: Twenty-five patients received ≥1 dose of AMG 820. AMG 820 was tolerated up to 20 mg/kg; the MTD was not reached. One dose-limiting toxicity was observed (20 mg/kg; nonreversible grade 3 deafness). Most patients (76%) had treatment-related AEs; the most common were periorbital edema (44%), increased aspartate aminotransferase (AST; 28%), fatigue (24%), nausea (16%), increased blood alkaline phosphatase (12%), and blurred vision (12%). No patients had serious or fatal treatment-related AEs; 28% had grade ≥3 treatment-related AEs. Grade 3 AST elevations resolved when treatment was withheld. AMG 820 showed linear pharmacokinetics, with minimal accumulation (<2-fold) after repeated dosing. Pharmacodynamic increases in serum CSF1 concentrations and reduced numbers of skin macrophages were observed. Best response was stable disease in 8 patients (32%).Conclusions: AMG 820 was tolerated with manageable toxicities up to 20 mg/kg every 2 weeks. Pharmacodynamic response was demonstrated, and limited antitumor activity was observed. Clin Cancer Res; 23(19); 5703-10. ©2017 AACR.

Relative value of multiple plasma biomarkers as risk factors for coronary artery disease and death in an angiography cohort.

BACKGROUND: Although elevated levels of C-reactive protein (CRP), interleukin (IL)-6, serum amyloid A protein (SAA) and total homocysteine (tHcy) have been associated with the increased likelihood of cardiovascular events, the relative or combined utility of these biomarkers in predicting atherosclerosis and death in an angiography cohort is unknown. METHODS: A cohort of 1117 consecutive patients (797 men and 320 women), referred to 2 Vancouver teaching hospitals for selective coronary angiography, was recruited between 1993 and 1995. Angiography results were obtained for 1019 patients. In 2004 we determined that of 1050 patients who could be traced, 231 had died, 95 of CAD-related causes. We compared the relative utility of baseline measurements of CRP, IL-6, SAA and tHcy as well as of lipids for predicting angiographic CAD and all-cause and CAD-related death. RESULTS: The risk of death increased across quartiles for CRP, IL-6, SAA and tHcy. When comparing the highest and lowest quartiles, the greatest hazard ratios were associated with IL-6 (2.57, 95% confidence interval [CI] 1.62-4.09) and tHcy (2.36, 95% CI 1.53-3.65). A Cox regression model containing all plasma biomarkers and traditional risk factors indicated that age, angiographic CAD and baseline plasma levels of IL-6 and tHcy remained independent predictors of CAD-related death, whereas age, sex, smoking, diabetes and apolipoprotein B levels were independent predictors of angiographic CAD. Kaplan-Meier survival curves indicated a utility in combining measures of CRP, SAA, IL-6 and tHcy for predicting risk of all-cause and CAD-related death. INTERPRETATION: A comparison of elevated levels of CRP, IL-6, SAA and tHcy with traditional CAD risk factors indicated that IL-6 and tHcy were the strongest independent biomarkers for CAD-related death. Elevated levels of multiple biomarkers were associated with an increasing rate of all-cause and CAD-related death.

Vascular accumulation of a novel photosensitizer, MV6401, causes selective thrombosis in tumor vessels after photodynamic therapy.

The antivascular effects of photodynamic therapy (PDT) and their mechanisms are not clearly understood. Here, we examined the effects of PDT with a novel photosensitizer MV6401 on the microvasculature in a mammary tumor (MCaIV) grown in a murine dorsal skinfold chamber and in normal tissue controls. The mice were irradiated with light 15 min after i.v. administration of MV6401 when the drug was localized only in the vascular compartment, as shown by fluorescence microscopy and immunohistochemistry. PDT with MV6401 caused a dose-dependent biphasic blood flow stasis and vascular hyperpermeability, as determined by intravital microscopy. This biphasic response was classified into two components: (a) an acute response observed immediately after PDT; and (b) a long-term response observed at times greater than 3 h after PDT. The acute temporal vascular effects were characteristic of vasoconstriction but not of thrombus formation. However, the long-term vascular shutdown was mediated by thrombus formation, as evidenced by histological evaluation and inhibition with heparin. Minimal effects were observed in normal vessels after antivascular doses used against the tumor, but there was no long-term vascular damage. In concert with the stasis, a dose-dependent tumor growth delay was observed. This study provides mechanistic insights into antitumor vascular effects of PDT and suggests novel strategies for tumor treatment with PDT.

Targeting tumor vasculature and cancer cells in orthotopic breast tumor by fractionated photosensitizer dosing photodynamic therapy.

Photodynamic therapy (PDT) is a locally administered therapy currently being investigated in various clinical and preclinical settings. Tumor-host interaction is an important determinant of tumor biology and response to treatments. Here we report for the first time the effects of PDT on an orthotopic, murine mammary tumor model. PDT utilizes two individually nontoxic components: (a) the localization in the target site of a photosensitizing drug; and (b) the activation of the photosensitizer by light of an appropriate wavelength and energy. PDT after a single dose of the photosensitizer MV6401 induced drug dose-dependent, long-term blood flow shut down and tumor growth delay in the MCaIV tumor, grown in the mammary fat pad. The plasma half-life of MV6401 was approximately 20 min, and the drug was confined to the vascular compartment shortly after administration. However, it accumulated in the interstitial compartment at 2-6 h after the administration. Two equal MV6401 doses injected 4 h and 15 min before the light administration allowed the photosensitizer to localize in both vascular and tumor cell compartments. The fractionated drug dose PDT more effectively induced tumor growth delay than the same total dose given as a single dose either at 4 h or at 15 min before light administration. The long-term effect of the fractionated drug PDT on blood flow was also more extensive than single-dose PDT. Fractionated photosensitizer dosing PDT offers a new strategy to optimize PDT therapy.

Cholesterol ester transfer protein (CETP) Taq1B polymorphism influences the effect of a standardized cardiac rehabilitation program on lipid risk markers.

Cardiac rehabilitation programs (CR) are standard treatment for patients with coronary artery disease (CAD), yet a large variation in risk factor and lipoprotein changes exists. We investigated the role of three common genetic polymorphisms (CETP Taq1B, LIPC -514 and apo E) associated with alterations of lipoprotein metabolism, in patients before and after standardized CR. Three-hundred and seven patients were recruited for this study. DNA samples were collected and all three genotypes were determined for every patient. While the hepatic lipase LIPC promoter polymorphism and apo E genotype showed little or no correlation with response to CR, CETP Taq1B showed significant association with changes in plasma lipid and lipoproteins. The B1 homozygotes for CETP Taq1B genotype showed significant reduction in TC (-0.25+/-0.07, p < 0.01), LDL-C (-0.15+/-0.06, p < 0.050) and TG (-0.20+/-0.08, p < 0.05). B2 carriers showed no significant change in these parameters. HDL-C, exercise capacity and BMI improved independent of genotype. Individuals with the B1B1 genotype appear to respond well to CR, whereas B2 carriers exhibit marginal gains in lipoprotein risk factors. Although the B2 carriers had similar benefits in exercise capacity and weight reduction, long-term consequences of little or no change in lipoprotein risk factors require further investigation to establish appropriate management strategies.

AMG 595, an Anti-EGFRvIII Antibody-Drug Conjugate, Induces Potent Antitumor Activity against EGFRvIII-Expressing Glioblastoma.

Epidermal growth factor receptor variant III (EGFRvIII) is a cancer-specific deletion mutant observed in approximately 25% to 50% of glioblastoma multiforme (GBM) patients. An antibody drug conjugate, AMG 595, composed of the maytansinoid DM1 attached to a highly selective anti-EGFRvIII antibody via a noncleavable linker, was developed to treat EGFRvIII-positive GBM patients. AMG 595 binds to the cell surface and internalizes into the endo-lysosomal pathway of EGFRvIII-expressing cells. Incubation of AMG 595 with U251 cells expressing EGFRvIII led to potent growth inhibition. AMG 595 treatment induced significant tumor mitotic arrest, as measured by phospho-histone H3, in GBM subcutaneous xenografts expressing EGFRvIII. A single intravenous injection of AMG 595 at 17 mg/kg (250 µg DM1/kg) generated complete tumor regression in the U251vIII subcutaneous xenograft model. AMG 595 mediated tumor regression in the D317 subcutaneous xenograft model that endogenously expresses EGFRvIII. Finally, AMG 595 treatment inhibited the growth of D317 xenografts orthotopically implanted into the brain as determined by magnetic resonance imaging. These results demonstrate that AMG 595 is a promising candidate to evaluate in EGFRvIII-expressing GBM patients.

APOA5 gene polymorphism modulates levels of triglyceride, HDL cholesterol and FERHDL but is not a risk factor for coronary artery disease.

Variation in the APOA5 gene has been shown to be associated with triglyceride levels in several independent population studies. It was our objective to determine if a relationship existed between selected genotypes or haplotypes of the APOA5 gene and findings on selective coronary angiography (SCA) in an independent cohort. The Vancouver SCA Cohort consists of individuals referred for angiography between 1993 and 1995. DNA was extracted from 537 patients and analyzed for the -1131T>C and the c.56C>G polymorphisms which define three common haplotypes of the APOA5 gene. Plasma triglycerides and the fractional esterification rate in apoB-depleted lipoproteins (FER(HDL)), an index of high-density lipoprotein (HDL) composition, were significantly higher (P = 0.01 and P = 0.001, respectively), and HDL cholesterol (HDL-C) was significantly lower (P = 0.03) in Caucasians with genotypes containing the minor allele of the -1131T>C polymorphism compared to the homozygotes for the major allele. However, there was no relationship between the c.56C>G polymorphism of the APOA5 gene and any of the measured lipid and lipoprotein parameters. Subjects homozygous for the common haplotype APOA5*1 had decreased triglyceride levels and FER(HDL) (P = 0.04 and P < 0.001, respectively) and increased HDL-C levels (P = 0.01) compared to subjects with all other haplogenotypes. Multivariate linear regression analysis indicated that the -1131T>C polymorphism remained an independent predictor of triglyceride, HDL-C, and FER(HDL) following adjustment of several variables including age, gender, body mass index, diabetes, lipid lowering and beta-blocker medication. The APOA5*1/*1 haplogenotype remained an independent predictor of HDL-C and FER(HDL) following adjustment of the same variables. The relationship between APOA5 genotype or haplogenotype and FER(HDL) remained significant even after the addition of both HDL-C and triglyceride to the model. However, there was no association between APOA5 gene polymorphisms or haplotypes and coronary artery disease as determined by angiography.

Lecithin: cholesterol acyltransferase (LCAT) deficiency and risk of vascular disease: 25 year follow-up.

We have reassessed the clinical and biochemical status of a large Canadian kindred with LCAT deficiency 25 years after the initial investigations. There have been no vascular events or death in this family over the 25 years. Both the homozygous (N = 2) and heterozygous (N = 9) patients had highly abnormal lipid profiles with low HDL-C (extreme in the homozygotes); apo B levels were high in the heterozygotes. Lipoprotein and hepatic lipase activities were low in the homozygotes and several heterozygotes. In the two homozygotes the carotid intima media thickness (IMT) was above 75th percentile expected for age and gender. However, the IMT abnormalities were much more pronounced in the heterozygotes, four of whom also had detectable plaques. The homozygotes had only minimal increases in IMT, no plaques, no IMT changes over the last 4 years and normal endothelial function. We conclude that, in this kindred, no significant vascular changes were observed in the homozygotes. However, heterozygocity for LCAT deficiency is associated with both an atherogenic lipid profile and vascular abnormalities.