Impact of oral abrocitinib on signs, symptoms and quality of life among adolescents with moderate-to-severe atopic dermatitis: an analysis of patient-reported outcomes

Background

A significant improvement in clinical signs was demonstrated with abrocitinib relative to placebo in adolescents with moderate‐to‐severe atopic dermatitis (AD) in three phase 3, randomized, double‐blinded, placebo‐controlled studies (JADE TEEN [ClinicalTrials.gov, NCT03796676], JADE MONO‐1 [NCT03349060] and JADE MONO‐2 [NCT03575871]).

Objectives

To evaluate the impact of abrocitinib on patient‐reported signs/symptoms, including sleep loss and quality of life among adolescents with moderate‐to‐severe AD.

Methods

JADE TEEN, JADE MONO‐1 and JADE MONO‐2 were conducted in the Asia‐Pacific region, Europe and North America and included patients aged 12–17 years with moderate‐to‐severe AD and inadequate response to ≥ 4 consecutive weeks of topical medication or treatment with systemic therapy for AD. Patients were randomly assigned (1 : 1 : 1, JADE TEEN; 2 : 2 : 1, JADE MONO‐1/‐2) to receive once‐daily oral abrocitinib (200 or 100 mg) or placebo for 12 weeks in combination with topical therapy (JADE TEEN) or as monotherapy (JADE MONO‐1/‐2). Data from adolescent patients in JADE MONO‐1/‐2 were pooled for these analyses.

Results

At week 12, more adolescents treated with abrocitinib (200 or 100 mg) vs. placebo achieved a ≥ 4‐point improvement from baseline in the Patient‐Oriented Eczema Measure in JADE TEEN (83.9% and 77.0% vs. 60.2%) and JADE MONO‐1/‐2 (83.0% and 69.4% vs. 43.5%) and a ≥ 6‐point improvement from baseline in the Children’s Dermatology Life Quality Index in JADE TEEN (73.8% and 67.5% vs. 56.5%) and JADE MONO‐1/‐2 (70.0% and 57.1% vs. 19.0%). Significant improvements in SCORing Atopic Dermatitis Visual Analog Scale for sleep loss scores were demonstrated with abrocitinib vs. placebo at weeks 2‐12 in JADE TEEN and JADE MONO‐1/‐2.

Conclusions

Patient‐reported signs/symptoms, including reduction of sleep loss and quality of life, were substantially improved with abrocitinib monotherapy or combination therapy relative to placebo in adolescents with moderate‐to‐severe AD.

Comparative efficacy and safety of systemic therapies used in moderate-to-severe atopic dermatitis: a systematic literature review and network meta-analysis

Given the lack of head-to-head studies of systemic therapies in moderate-to-severe atopic dermatitis (AD), network meta-analyses (NMAs) can provide comparative efficacy and safety data to inform clinical decision-making. In this NMA, eligible randomized controlled trials (RCTs) published before 24 October 2019 were identified by a systematic literature review. Short-term (12-16 weeks) efficacy (Investigator's Global Assessment [IGA] and Eczema Area and Severity Index [EASI] responses), patient-reported outcomes (PROs) and safety data from each trial were abstracted and analysed separately for monotherapy and combination therapy (systemic plus topical anti-inflammatory therapy). RCTs were analysed in fixed-effects and random-effects Bayesian NMA models. Overall, 19 phase 2 and phase 3 RCTs of abrocitinib, baricitinib, dupilumab, lebrikizumab, nemolizumab, tralokinumab and upadacitinib were included. In monotherapy RCTs, upadacitinib 30 mg once daily (QD) had the numerically highest efficacy (83.6% achieved ≥50% improvement in EASI [EASI-50 response]), followed by abrocitinib 200 mg QD (74.6%), upadacitinib 15 mg QD (70.5%), dupilumab 300 mg every 2 weeks (Q2W) (63.4%) and abrocitinib 100 mg QD (56.7%). Similar trends in EASI-75 and EASI-90 response were observed. In combination therapy RCTs, abrocitinib 200 mg QD had the highest EASI-50 (86.6%), followed by dupilumab 300 mg Q2W (82.4%) and abrocitinib 100 mg QD (79.7%). Similar findings were observed for IGA response and PROs. In monotherapy and combination therapy RCTs, the probability of treatment-emergent adverse events (TEAEs) was higher among all active treatments than with placebo (except for dupilumab 300 mg Q2W [odds ratio (OR), 0.96; 95% credible interval (CrI), 0.45-2.18] and abrocitinib 100 mg QD [OR, 0.95; 95% CrI, 0.35-2.66] in combination therapy RCTs), although active treatments did not significantly differ from one another. Abrocitinib, dupilumab and upadacitinib were consistently the most effective systemic therapies in adult and adolescent patients with AD, with no significant TEAE differences in short-term RCTs.

The effect of ordered and partially ordered surface topography on bone cell responses: a review

Current understanding of the role of ordered and partially ordered surface topography in bone cell responses for bone implant design.

Potential neurogenic and vascular roles of nitric oxide in migraine headache and aura

It has long been known that nitrate and nitrite medications consistently cause significant headache as a side effect. Classical research has shown that cerebral vasodilation accompanies the use of these medications. More modern studies suggest that these vasodilators exert their action on blood vessels via nitric oxide and its second messenger, cyclic guanosine monophosphate. This paper reviews research studies and theoretical articles which address the concept that nitric oxide plays a major role in the vasodilation associated with the headache phase of migraine with aura. A brief discussion of nitric oxide biochemistry and pharmacology follows. In addition, there is a review of evidence examining the possible contributions of nitric oxide to the neurogenic and vascular events associated with spreading cortical depression, an animal model of migraine aura. The paradoxical hypotheses that nitric oxide may contribute to both the propagation of spreading cortical depression and its limitation are presented. Finally, a rationale for the experimental use of nitric oxide agonists and antagonists in the abortion of migraine aura is introduced.

Expression of the Skate (Raja erinacea) AE1 Osmolyte Channel in Xenopus laevis Oocytes: Monovalent Cation Permeability

The aim of this study was to express the cloned skate anion exchanger 1 (skAE1) in Xenopus oocytes and determine whether the differences in monovalent cation permeabilities in hypotonically stimulated skate and trout erythrocytes could be due to differences in the presence or absence of intracellular channel regulators between the two species or in the intrinsic permeability properties of the channels themselves. The expressed protein (skAE1) was inserted into the oocyte cell membrane and facilitated both Cl- exchange and taurine transport. Expression of skAE1 in oocytes showed similar monovalent cation permeabilities as previously reported for skate erythrocytes and different from both trout erythrocytes and trAE1 expressed in Xenopus oocytes. These results show that the skAE1 expressed in oocytes functions in a manner similar to that of the osmolyte channel in hypotonically activated skate erythrocytes and supports the hypothesis that differences in the monovalent cation permeabilities of the osmolyte channels in skate and trout RBCs resides in the differences in permeability properties of the channels between the two species.

Leptin directly regulates bone cell function in vitro and reduces bone fragility in vivo

Fat mass is an important determinant of bone density, but the mechanism of this relationship is uncertain. Leptin, as a circulating peptide of adipocyte origin, is a potential contributor to this relationship. Recently it was shown that intracerebroventricular administration of leptin is associated with bone loss, suggesting that obesity should be associated with low bone mass, the opposite of what is actually found. Since leptin originates in the periphery, an examination of its direct effects on bone is necessary to address this major discrepancy. Leptin (>10(-11) m) increased proliferation of isolated fetal rat osteoblasts comparably with IGF-I, and these cells expressed the signalling form of the leptin receptor. In mouse bone marrow cultures, leptin (>or=10(-11) m) inhibited osteoclastogenesis, but it had no effect on bone resorption in two assays of mature osteoclasts. Systemic administration of leptin to adult male mice (20 injections of 43 micro g/day over 4 weeks) reduced bone fragility (increased work to fracture by 27% and displacement to fracture by 21%, P<0.001). Changes in tibial histomorphometry were not statistically significant apart from an increase in growth plate thickness in animals receiving leptin. Leptin stimulated proliferation of isolated chondrocytes, and these cells also expressed the signalling form of the leptin receptor. It is concluded that the direct bone effects of leptin tend to reduce bone fragility and could contribute to the high bone mass and low fracture rates of obesity. When administered systemically, the direct actions of leptin outweigh its centrally mediated effects on bone, the latter possibly being mediated by leptin's regulation of insulin sensitivity.

Type 1 diabetes mellitus and oral health: assessment of coronal and root caries

OBJECTIVES

The oral health of a large cohort of adult insulin-dependent diabetic patients (Type 1), diagnosed 24 years previously with juvenile onset, was comprehensively assessed. This paper describes the prevalence of coronal and root caries in this adult Type 1 diabetic population and evaluates demographic, dietary, behavioral, physiologic, salivary and medical variables associated with decayed and filled surfaces in the crown (DFS) or root (RDFS).

METHODS

Type 1 diabetes mellitus subjects participating in this oral health evaluation had been monitored for 6-8 years as participants in the University of Pittsburgh, Department of Epidemiology, longitudinal study of medical complications associated with diabetes. Four hundred and six diabetic subjects received a comprehensive oral health examination during one of their regularly scheduled medical visits. Oral assessments included coronal and root caries, missing teeth, edentulism, periodontal status, soft tissue pathologies, salivary function and health behaviors. Sixteen diabetic subjects and one control subject were edentulous. Coronal and root caries data from the remaining 390 dentate diabetic subjects were compared with 202 dentate nondiabetic control subjects.

RESULTS

The adult Type 1 diabetic subjects were not found to have significantly higher DFS rates as compared with our control subjects or published age-adjusted NHANES III findings. Both control and diabetic subjects had low decayed to filled tooth surface ratios. A linear regression model evaluated possible associations with coronal decayed and filled tooth surfaces (DFS) within the diabetic population. Significant factors included older age, women, fewer missing teeth, more frequent use of dental floss, more frequent visits to the dentist during the last 12 months, and diabetic nephropathy. The prevalence of RDFS was higher in the diabetic subjects as compared to recruited control subjects. Neither dietary behaviors nor glycemic control were found to contribute to coronal or root caries.

CONCLUSIONS

Factors associated with presence of coronal and root caries and fillings are discussed. Possible causes and implications for the association between DFS and diabetic nephropathy are provided.

Induction of osteoclasts from CD14-positive human peripheral blood mononuclear cells by receptor activator of nuclear factor kappaB ligand (RANKL)

Osteoclasts are bone-resorbing cells that are derived from haemopoietic precursors, including cells present in peripheral blood. The recent identification of RANKL [receptor activator of nuclear factor (NF)-kappaB ligand], a new member of the tumour necrosis factor ligand superfamily that has a key role in osteoclastogenesis, has allowed the in vitro generation of osteoclasts in the absence of cells of the stromal/osteoblast lineage. Human peripheral blood mononuclear cells (PBMC) cultured in vitro with soluble RANKL and human macrophage colony-stimulating factor form osteoclasts. However, PBMC are heterogeneous, consisting of subsets of monocytes and lymphocytes as well as other blood cells. As the CD14 marker is strongly expressed on monocytes, the putative osteoclast precursor in peripheral blood, we have selected CD14(+) cells from PBMC to examine their osteoclastogenic potential and their expression of novel members of the tumour necrosis factor superfamily involved in osteoclastogenesis. Highly purified CD14(+) cells demonstrated mRNA expression of receptor activator of NF-kappaB, but no expression of RANKL or osteoprotegerin, whereas PBMC expressed mRNAs for all three factors. CD14(+) (but not CD14(-)) cells cultured on bone slices for 21 days with human macrophage colony-stimulating factor and soluble RANKL generated osteoclasts and showed extensive bone resorption. Similar numbers of osteoclasts were generated by 10(5) CD14(+) cells and 10(6) PBMC, but there was significantly less intra-assay variability with CD14(+) cells, suggesting the absence of stimulatory/inhibitory factors from these cultures. The ability of highly purified CD14(+) cells to generate osteoclasts will facilitate further characterization of the phenotype of circulating osteoclast precursors and cell interactions in osteoclastogenesis.

EGF-genistein inhibits neointimal hyperplasia after vascular injury in an experimental restenosis model

A murine model of vascular injury-induced neointimal hyperplasia was developed by using a photoactive dye, rose bengal. Photoactivation of rose bengal induced vascular injury to the femoral arteries of C57B1/6 mice and resulted in an occlusive neointimal hyperplasia after 4 weeks. The cellular elements of the hyperplastic neointima were found to be alpha-actin-positive vascular smooth muscle cells expressing epidermal growth factor (EGF) receptor at high levels. EGF-Gen, an EGF-R-specific inhibitor with potent anticancer activity, suppressed the formation of hyperplastic neointima. Morphometric analysis of serial tissue sections at 4 weeks after vascular injury showed that in 75% of the EGF-Gen-treated mice, the maximal stenosis index was only 0.44 +/- 0.13, whereas in 75% of phosphate-buffered saline (PBS)-treated mice, the maximal stenosis index was 1.20 +/- 0.25. The mean neointima/media ratios for areas of maximum neointimal hyperplasia were 0.59 +/- 0.16 (n = 24) for the EGF-Gen-treated group, 0.99 +/- 16 (n = 45) for the PBS group (EGF-Gen vs. PBS, p = 0.0017), and 1.03 +/- 18 (n = 8) for group treated with unconjugated genistein (EGF-Gen vs. Gen, p = 0.0088). EGF-Gen treatment of mice with vascular injury to the left femoral artery was not associated with any clinical signs of toxicity or histopathologic lesions in any of the organs, including the uninjured right femoral artery. EGF-Gen also inhibited VSMC migration in vitro, without affecting VSMC proliferation and viability, suggesting that EGF-Gen is blocking neointima formation by inhibiting cellular migration to vascular injury sites. In conclusion, EGF-Gen may be useful as a nontoxic prophylactic agent for prevention of restenosis in clinical settings.

Expression of functional RANK on mature rat and human osteoclasts

Although the important roles of RANK/RANKL in osteoclastogenesis have been established, their roles in the regulation of mature osteoclasts remain uncertain. Microisolation has been used to obtain pure populations of rat and human osteoclasts for RT-PCR analysis. RANK and calcitonin receptor mRNA was detected in all the samples whereas OPG and ALP mRNA was not present in any. RANKL mRNA was detected in two of eight rat and one of four human samples. Treatment of osteoclasts with soluble RANKL resulted in translocation of NF-kappaB to the nucleus and elevation of cytosolic and nuclear calcium levels. We have shown that RANK is highly expressed in mature osteoclasts and that its stimulation by RANKL results in activation of NF-kappaB and calcium signalling.

Treatment of therapy-refractory B-lineage acute lymphoblastic leukemia with an apoptosis-inducing CD19-directed tyrosine kinase inhibitor

Seven children and eight adults with CD19+ B-lineage acute lymphoblastic leukemia, as well as one adult with chronic lymphocytic leukemia, were treated with the CD19 receptor-directed tyrosine kinase inhibitor B43-Genistein. All patients had failed previous chemotherapy regimens, and six patients had relapsed after bone marrow transplantation. B43-Genistein was administered as a 1-hour i.v. infusion at 0.1-0.32 mg/kg/day dose levels for 10 consecutive days or 3 consecutive days weekly for a total of nine doses. B43-Genistein was well tolerated by all patients with no life-threatening side effects. There were six episodes of grade 2-3 fever, two of which were clearly drug related, one episode each of grade 3 myalgia, grade 2 sinus tachycardia, and grade 2 vascular leak syndrome. There was one durable complete remission and two transient responses. Pharmacokinetic analyses in 12 patients revealed a plasma half-life of 20 +/- 5 h, mean residence time of 24 +/- 5 h, and a systemic clearance rate of 20 +/- 3 ml/h/kg. Moderate levels of human antimouse antibody (HAMA) ranging from 20-87 ng/ml were detected in the day 28 blood samples from three of nine cases examined. Treatment of these three HAMA-positive patients with a second course of B43-Genistein did not yield measurable immunoconjugate levels in the plasma, indicating that the administered B43-Genistein molecules were rapidly cleared from circulation due to the HAMA. On the basis of its acceptable toxicity profile and its ability to elicit objective responses at nontoxic dose levels, B43-Genistein may provide the basis for an effective treatment strategy for B-lineage acute lymphoblastic leukemia patients who have failed standard therapy.

Clinical pharmacokinetics of the CD19 receptor-directed tyrosine kinase inhibitor B43-Genistein in patients with B-lineage lymphoid malignancies

The authors examined the pharmacokinetics of the CD19 receptor-directed tyrosine kinase inhibitor B43-Genistein in 17 patients (4 children, 13 adults) with B-lineage lymphoid malignancies, including 12 patients with acute lymphoblastic leukemia (ALL) and 5 patients with non-Hodgkin's lymphoma (NHL). The immunoconjugate was administered intravenously as a 1-hour continuous infusion at a dose level of either 0.1 mg/kg (N = 12) or 0.18 mg/kg (N = 5), and the plasma concentration-time data were modeled by using the WinNonlin program to estimate the pharmacokinetic parameters. Pharmacokinetic analyses revealed a plasma half-life of 19 +/- 4 hours, mean residence time of 22 +/- 4 hours, and a systemic clearance of 18 +/- 2 mL/h/kg. The average (mean +/- SEM) values for the maximum plasma concentration Cmax, volume of distribution at steady state (Vss), and area under curve (AUC) were 1092 +/- 225 ng/ml, 291 +/- 37 mL/kg, and 9987 +/- 2021 micrograms x h/L, respectively. The AUC values were higher at the 0.18 mg/kg dose level than at the 0.1 mg/kg dose level (16,848 +/- 5118 micrograms x h/L vs. 7128 +/- 1156 micrograms x h/L, p = 0.009). Patients with ALL had a significantly larger volume of distribution at steady state (332 +/- 47 mL/kg vs. 191 +/- 12 mL/kg, p = 0.04), faster clearance (21 +/- 3 mL/h/kg vs. 11 +/- 2 mL/h/kg, p = 0.03), and lower dose-corrected AUC than patients with NHL (6010 +/- 836 micrograms x h/L vs. 12,044 +/- 2707 micrograms x h/L, p = 0.006). There was a trend toward faster clearance rates (23 +/- 4 mL/h/kg vs. 16 +/- 3 mL/h/kg, p = 0.1), shorter elimination half-lives (5.7 +/- 3.6 hours vs. 13 +/- 8.8 hours, p = 0.1), and shorter mean residence times (11 +/- 3 hours vs. 25 +/- 5 hours, p = 0.08) for non-Caucasian patients as compared to Caucasian patients. When compared to adult patients, pediatric patients showed a significantly larger volume of distribution at steady state (418 +/- 82 mL/kg vs. 252 +/- 34 mL/kg, p = 0.02) and a longer elimination half-lives (18.4 +/- 13.6 hours vs. 8.7 +/- 6.7 hours, p = 0.04). The pharmacokinetics of B43-Genistein was not affected by the gender of the patients or by bone marrow transplantation in past medical history. Overall, B43-Genistein showed favorable pharmacokinetics in this heavily pretreated leukemia/lymphoma patient population, which is reminiscent of its recently reported favorable pharmacokinetics in cynomolgus monkeys. To our knowledge, this is the first clinical pharmacokinetics study of a tyrosine kinase inhibitor containing immunoconjugate.

X-ray crystallographic analysis of the structural basis for the interactions of pokeweed antiviral protein with its active site inhibitor and ribosomal RNA substrate analogs

The pokeweed antiviral protein (PAP) belongs to a family of ribosome-inactivating proteins (RIP), which depurinate ribosomal RNA through their site-specific N-glycosidase activity. We report low temperature, three-dimensional structures of PAP co-crystallized with adenyl-guanosine (ApG) and adenyl-cytosine-cytosine (ApCpC). Crystal structures of 2.0-2.1 A resolution revealed that both ApG or ApCpC nucleotides are cleaved by PAP, leaving only the adenine base clearly visible in the active site pocket of PAP. ApCpC does not resemble any known natural substrate for any ribosome-inactivating proteins and its cleavage by PAP provides unprecedented evidence for a broad spectrum N-glycosidase activity of PAP toward adenine-containing single stranded RNA. We also report the analysis of a 2.1 A crystal structure of PAP complexed with the RIP inhibitor pteoric acid. The pterin ring is strongly bound in the active site, forming four hydrogen bonds with active site residues and one hydrogen bond with the coordinated water molecule. The second 180 degrees rotation conformation of pterin ring can form only three hydrogen bonds in the active site and is less energetically favorable. The benzoate moiety is parallel to the protein surface of PAP and forms only one hydrogen bond with the guanido group of Arg135.

Type 1 diabetes mellitus and oral health: assessment of periodontal disease

BACKGROUND

The periodontal disease status of 320 dentate adults, diagnosed 23.7 years previously with Type 1 insulin dependent diabetes mellitus, was evaluated. These patients had been monitored at 2-year intervals as part of a large University of Pittsburgh longitudinal study assessing the medical complications associated with insulin dependent diabetes.

METHODS

During one of their regularly scheduled medical examinations, a group of 320 adult dentate subjects (mean age of 32.1 years) received a periodontal examination as part of a comprehensive oral health assessment. The oral health assessment collected data regarding demographics, oral health behaviors, tooth loss, coronal and root caries, salivary functions, and soft tissue pathologies. For the periodontal assessments, 3 facial sites (mesial, midcervical, distal) of the teeth in the right maxillary/left mandibular or left maxillary/right mandibular quadrants were evaluated for calculus, bleeding on probing (BOP) and loss of gingival attachment (LOA).

RESULTS

Attachment loss was significantly greater for older patients whereas BOP and calculus levels were relatively constant across age categories. Univariate analyses of factors possibly related to extensive periodontal disease (LOA > or =4 mm for at least 10% of sites examined) indicated an association with older age; lower income and education; past and current cigarette smoking; infrequent visits to the dentist; tooth brushing less than once per day; older age of onset; longer duration of diabetes; and the diabetic complication of neuropathy. A multivariate regression model of all possibly significant factors found current cigarette use (odds ratio [OR] = 9.73), insulin dependent diabetes onset after 8.4 years of age (OR = 3.36), and age greater than 32 years (OR = 3.00) explained the majority of the extensive periodontal disease in this group of diabetic patients.

CONCLUSIONS

Management and prevention of extensive periodontal disease for Type 1 diabetic patients should include strong recommendations to discontinue cigarette smoking.

Type 1 diabetes mellitus and oral health: assessment of tooth loss and edentulism

OBJECTIVE

The oral health of an adult population previously diagnosed with juvenile onset insulin dependent-diabetes was comprehensively assessed. The goal of this exploratory cross-sectional evaluation was to described the characteristics related to partial tooth loss edentulism in subjects with Type 1 diabetes mellitus.

METHODS

An adult population of 406 Type 1 diabetes mellitus subjects, who had been monitored for 6-8 years as part of a University of Pittsburgh longitudinal study of medical complications associated with diabetes, received an oral health examination for missing teeth, edentulism, coronal and root caries, periodontal status, and oral health behaviors.

RESULTS

Of the 406 subjects evaluated, 204 had no missing teeth, 186 had partial tooth loss (1-27 missing teeth), and 16 were edentulous. Patients who had partial tooth loss or who were edentulous were generally older; had lower incomes and levels of education; and had higher rates of nephropathy, neuropathy, retinopathy, and peripheral vascular disease. A logistic regression model found partial tooth loss to be significantly associated with extensive periodontal disease in remaining teeth (OR = 7.35), a duration of diabetes longer than 24 years (OR = 5.32), not using dental floss (OR = 2.37), diabetic neuropathy (OR = 2.29), household income less than $20,000 (OR = 2.21), multiple coronal caries and fillings (OR = 1.98), and bleeding on probing (OR = 1.82).

CONCLUSIONS

Although the majority of these adult Type 1 diabetes patients had serious medical complications associated with their diabetes, the possible impact of diabetes mellitus on oral health should be included in their overall management.

Treatment of human B-cell precursor leukemia in SCID mice by using a combination of the anti-CD19 immunotoxin B43-PAP with the standard chemotherapeutic drugs vincristine, methylprednisolone, and L-asparaginase

We have compared the antileukemic activity of the investigational biotherapeutic agent B43-PAP to the antileukemic activities of the standard chemotherapeutic drugs vincristine (VCR), methylprednisolone (PDN), L-asparaginase (L-ASP) as single agents as well as in a 3-drug combination regimen ("VPL") using a SCID mouse model of human B-cell precursor (BCP) acute lymphoblastic leukemia (ALL). When mice (N = 95) were challenged with 1 x 10(6) NALM-6 leukemia cells, all of them died of disseminated leukemia with a median event-free survival (EFS) of 47 +/- 6 days. B43-PAP was more active than VCR, PDN, or L-ASP and the two-drug combinations VCR + B43-PAP, PDN + B43-PAP, or L-ASP + B43-PAP were not significantly more active than B43-PAP. The 120 days EFS outcome results were 46 +/- 13% for B43-PAP (Median EFS = 92 +/- 22 days), 0 +/- 0% for VCR (Median EFS = 49 +/- 1 days), 40 +/- 22% for PDN (Median EFS = 100 +/- 20 days), 0 +/- 0% for L-ASP (Median EFS = 41 +/- 1 days), 60 +/- 22% for VCR + B43-PAP (Median EFS = >120 days), 60 +/- 22% for PDN + B43-PAP (Median EFS = >120 days), and 50 +/- 25% for L-ASP + B43-PAP (Median EFS = 93 +/- 27 days), When mice (N = 61) were challenged with 5 x 10(6) NALM-6 cells, all of them rapidly died of disseminated leukemia with a median EFS of 37 +/- 3 days. The 3-drug combination "VPL" (Median EFS = 75 +/- 23 days) was slightly less active than B43-PAP (Median EFS = 84 +/- 19 days) (P = 0.09). Notably, the combination of "VPL" with B43-PAP (i.e., VPLB) resulted in 100% survival. By comparison, the combination of "VPL" with daunorubicin (i.e., VPLD) (Median EFS = 69 +/- 31 days) was not more active than VPL. To our knowledge, this preclinical study is the first to demonstrate the feasibility and superb antileukemic activity of immunochemotherapy using anti-CD19 immunotoxin in combination with the standard 3-drug combination "VPL" against BCP ALL.

In vivo toxicity and pharmacokinetic features of B43(Anti-CD19)-Genistein immunoconjugate

B43(anti-CD19)-Genistein immunoconjugate targets genistein, a naturally occurring protein tyrosine kinase inhibitory isoflavone to the membrane-associated anti-apoptotic CD19-LYN complexes and triggers apoptotic cell death. In this preclinical study, the toxicity profiles of B43-Genistein as well as unconjugated genistein were evaluated in mice. B43-Genistein and genistein were administered either as single bolus injections or daily injections for 10 consecutive days via the intraperitoneal route to mice. Genistein was not toxic to mice at the highest dose of 40 mg/kg and no test article-related histopathological lesions were found in any of the 64 genistein-treated mice. B43-Genistein had a significantly longer elimination half-life and slower plasma and tissue clearance than unconjugated genistein. B43-Genistein was not toxic to mice at the highest single dose of 40 mg/kg or highest cumulative dose of 100 mg/kg and no test article-related histopathological lesions were found in any of the 108 mice treated with B43-genistein. To our knowledge, this is the first preclinical toxicity and pharmacokinetic study of a tyrosine kinase inhibitor-containing immunoconjugate.

Antitumor activity of TP3(anti-p80)-pokeweed antiviral protein immunotoxin in hamster cheek pouch and severe combined immunodeficient mouse xenograft models of human osteosarcoma

TP3-pokeweed antiviral protein (PAP) immunotoxin is directed against the p80 antigen on osteosarcoma cells. Previous studies have demonstrated that TP3-PAP kills clonogenic human osteosarcoma cells in vitro and shows significant antitumor activity in a murine soft tissue sarcoma model (P. M. Anderson, et al, Cancer Res., 55: 1321-1327, 1995.) In this study, we demonstrate that TP3-PAP elicits potent in vivo antitumor activity in a hamster cheek pouch model of human osteosarcoma. Furthermore, treatment with TP3-PAP at nontoxic dose levels significantly delayed the emergence and progression of leg tumors and markedly improved tumor-free survival in severe combined immunodeficient mice challenged with OHS human osteosarcoma cells. Thus, TP3-PAP may be useful in the treatment of poor risk osteosarcoma.

Reliability of self-reported heart murmur history: possible impact on antibiotic use in dentistry

Administration of prophylactic antibiotics to a dental patient with a history of heart murmur, rheumatic fever or mitral valve prolapse should be based on a reliable diagnosis of heart valve disease. The authors conducted a study of 68 diabetic patients who reported having these conditions and found that at least 65 percent of these patients actually had no evidence of a pathological heart murmur during two previous physical examinations. They concluded that a self-reported history of heart valve disease should not be the sole criterion for antibiotic premedication.

4-(3'-Bromo-4'hydroxylphenyl)-amino-6,7-dimethoxyquinazoline: a novel quinazoline derivative with potent cytotoxic activity against human glioblastoma cells

The novel quinazoline derivative 4-(3'-bromo-4'-hydroxylphenyl)-amino-6,7-dimethoxyquinazoline (WHI-P154) exhibited significant cytotoxicity against U373 and U87 human glioblastoma cell lines, causing apoptotic cell death at micromolar concentrations. The in vitro antiglioblastoma activity of WHI-P154 was amplified > 200-fold and rendered selective by conjugation to recombinant human epidermal growth factor (EGF). The EGF-P154 conjugate was able to bind to and enter target glioblastoma cells within 10-30 min via receptor (R)-mediated endocytosis by inducing internalization of the EGF-R molecules. In vitro treatment with EGF-P154 resulted in killing of glioblastoma cells at nanomolar concentrations with an IC50 of 813 +/- 139 nM, whereas no cytotoxicity against EGF-R-negative leukemia cells was observed, even at concentrations as high as 100 microM. The in vivo administration of EGF-P154 resulted in delayed tumor progression and improved tumor-free survival in a severe combined immunodeficient mouse glioblastoma xenograft model. Whereas none of the control mice remained alive tumor-free beyond 33 days (median tumor-free survival, 19 days) and all control mice had tumors that rapidly progressed to reach an average size of > 500 mm3 by 58 days, 40% of mice treated for 10 consecutive days with 1 mg/kg/day EGF-P154 remained alive and free of detectable tumors for more than 58 days with a median tumor-free survival of 40 days. The tumors developing in the remaining 60% of the mice never reached a size > 50 mm3. Thus, targeting WHI-P154 to the EGF-R may be useful in the treatment of glioblastoma multiforme.

In vivo toxicity, pharmacokinetics, and anticancer activity of Genistein linked to recombinant human epidermal growth factor

Epidermal growth factor receptor (EGFR)-associated protein tyrosine kinase (PTK) complexes have vital anti-apoptotic functions in human breast cancer cells. We have shown previously that targeting the naturally occurring PTK inhibitor genistein to the EGFR-associated PTK complexes using the EGF-Genistein (Gen) conjugate triggers rapid apoptotic cell death in human breast cancer cells and abrogates their in vitro clonogenic growth. In the present study, we examined the in vivo toxicity profile, pharmacokinetics, and anticancer activity of EGF-Gen. No toxicities were observed in mice treated with EGF-Gen at dose levels as high as 40 mg/kg administered i.p. as a single dose or 140 mg/kg administered i.p. over 28 consecutive days. EGF-Gen significantly improved tumor-free survival in a severe combined immune deficiency (SCID) mouse xenograft model of human breast cancer, when it was administered 24 h after inoculation of tumor cells. At 100 microg/kg/day x 10 days (1 mg/kg total dose), which is >100-fold less than the highest tested and nontoxic cumulative dose (ie., 140 mg/kg) in mice, EGF-Gen was more effective than cyclophosphamide (50 mg/kg/day x 2 days), Adriamycin (2.5 mg/kg x 1 day), or methotrexate (0.5 mg/kg x 1 day), the most widely used standard chemotherapeutic drugs for breast cancer, and resulted in 60% long-term tumor-free survival. Furthermore, treating SCID mice with established s.c. human breast cancer xenografts of 0.5-cm diameter with EGF-Gen at this dose level resulted in disappearance of the tumors in two of five mice and >50% shrinkage in three of five mice within 10 days, whereas all of the control tumors in five PBS-treated mice as well as five mice treated with unconjugated Gen (1 mg/kg/day x 10 days) showed >200% increase in diameter during the same observation period. EGF-Gen treatment reduced the growth rate of breast cancer xenografts of 1.0-cm diameter, but unlike with tumors of 0.5-cm diameter, it failed to cause shrinkage or disappearance of these larger tumors. The level of EGF-Gen systemic exposure that was effective in SCID mice was achieved in cynomolgus monkeys without any significant side effects detectable by clinical observation, laboratory studies, or histopathological examination of multiple organs. EGF-Gen might be useful in the treatment of breast cancer as well as other EGFR-positive malignancies.

Cytotoxic activity of epidermal growth factor-genistein against breast cancer cells

The receptor (R) for epidermal growth factor (EGF) is expressed at high levels on human breast cancer cells and associates with ErbB2, ErbB3, and Src proto-oncogene family protein tyrosine kinases (PTKs) to form membrane-associated PTK complexes with pivotal signaling functions. Recombinant human EGF was conjugated to the soybean-derived PTK inhibitor genistein (Gen) to construct an EGF-R-directed cytotoxic agent with PTK inhibitory activity. The EGF-Gen conjugate was capable of binding to and entering EGF-R-positive MDA-MB-231 and BT-20 breast cancer cells (but not EGF-R-negative NALM-6 or HL-60 leukemia cells) via its EGF moiety, and it effectively competed with unconjugated EGF for target EGF-R molecules in ligand binding assays. EGF-Gen inhibited the EGF-R tyrosine kinase in breast cancer cells at nanomolar concentrations, whereas the IC50 for unconjugated Gen was >10 microM. Notably, EGF-Gen triggered a rapid apoptotic cell death in MDA-MB-231 as well as BT-20 breast cancer cells at nanomolar concentrations. The EGF-Gen-induced apoptosis was EGF-R-specific because cells treated with the control granulocyte-colony stimulating factor-Gen conjugate did not become apoptotic. Apoptosis was dependent both on the PTK inhibitory function of Gen and the targeting function of EGF, because cells treated with unconjugated Gen plus unconjugated EGF did not undergo apoptosis. The IC50s of EGF-Gen versus unconjugated Gen against MDA-MB-231 and BT-20 cells in clonogenic assays were 30 +/- 3 nM versus 120 +/- 18 microM (P < 0.001) and 30 +/- 10 nM versus 112 +/- 17 microM (P < 0.001), respectively. Thus, the EGF-Gen conjugate is a >100-fold more potent inhibitor of EGF-R tyrosine kinase activity in intact breast cancer cells than unconjugated Gen and a >100-fold more potent cytotoxic agent against EGF-R+ human breast cancer cells than unconjugated Gen. Taken together, these results indicate that the EGF-R-associated PTK complexes have vital antiapoptotic functions in human breast cancer cells and may therefore be used as therapeutic targets.

Large scale manufacturing of B43(anti-CD19)-genistein for clinical trials in leukemia and lymphoma

We have conjugated the murine monoclonal anti-CD19 antibody B43 to the tyrosine kinase inhibitor genistein to construct an effective immunoconjugate against CD19 antigen positive hematologic malignancies. The scaled-up production and purification of B43 antibody, genistein, and B43-Genistein immunoconjugate permitted the manufacturing of a highly purified clinical-grade B43-Genistein preparation. In clonogenic assays, B43-Genistein elicited selective and potent cytotoxicity against CD19 antigen positive human leukemia cells. To our knowledge, this work represents the first effort of producing a clinical-grade genistein immunoconjugate for treatment of B-lineage leukemia and lymphoma.

TXU (anti-CD7)-pokeweed antiviral protein as a potent inhibitor of human immunodeficiency virus

We have evaluated the clinical potential of TXU (anti-CD7)-pokeweed antiviral protein (PAP) immunoconjugate (TXU-PAP) as a new biotherapeutic anti-human immunodeficiency virus (anti-HIV) agent by evaluating its anti-HIV type 1 (anti-HIV-1) activity in vitro, as well as in a surrogate human peripheral blood lymphocyte-severe combined immunodeficient (Hu-PBL-SCID) mouse model of human AIDS. The present report documents in a side-by-side comparison the superior in vitro anti-HIV-1 activity of TXU-PAP compared to the activities of zidovudine, 2',3'-didehydro-2',3'-dideoxythymidine, unconjugated PAP, and B53-PAP, an anti-CD4-PAP immunoconjugate. Notably, TXU-PAP elicited potent anti-HIV activity in the Hu-PBL-SCID mouse model of human AIDS without any side effects and at doses that were very well tolerated by cynomolgus monkeys. Furthermore, plasma samples from TXU-PAP-treated cynomolgus monkeys showed potent anti-HIV-1 activity in vitro.

Combined therapeutic efficacy of the thymidylate synthase inhibitor ZD1694 (Tomudex) and the immunotoxin B43(anti-CD19)-PAP in a SCID mouse model of human B-lineage acute lymphoblastic leukemia

The quinazoline antifolate N-(5-[N-(3,4-dihydro-2-methyl-4-oxoquinazolin-6-ylmethyl)-N- methylamino]-2-thenoyl)-L-glutamic acid (ZD1694; Tomudex) is a potent inhibitor of thymidylate synthase and causes cell death through disruption of DNA synthesis and repair by blocking the obligatory thymidine nucleotide synthesis. B43(anti-CD19)-PAP immunotoxin is a potent inhibitor of protein synthesis in CD19+ B-lineage acute lymphoblastic leukemia (ALL) cells and causes apoptosis. In this model, 100% of SCID mice challenged with 1 x 10(6) human NALM-6 B-lineage ALL cells develop overt and invariably fatal leukemia. All of the 22 control SCID mice treated with phosphate-buffered saline died of disseminated human leukemia between 31 and 61 days with a median survival of 41.2 days. Treatment with ZD 1694 resulted in improved leukemia-free survival with a median survival of 69.2 days (P < 0.001, log-rank test). B43-PAP treatment was more effective than ZD1694 (P=0.026) and resulted in 51.0% long-term leukemia-free survival with a median survival of 187.5 days (P < 0.0001. log-rank test). The combination of ZD1694 and B43-PAP was more effective than either agent alone and resulted in 100% long-term leukemia-free survival. To our knowledge, this preclinical study is the first to demonstrate the feasibility and therapeutic advantage of combining an anti-leukemia immunotoxin with a thymidylate synthase inhibitor.

In vivo toxicity and pharmacokinetic features of B43 (anti-CD19)-genistein immunoconjugate in nonhuman primates

B43 (anti-CD19)-genistein immunoconjugate targets genistein, a naturally occurring protein tyrosine kinase-inhibitory isoflavone to the membrane-associated antiapoptotic CD19-LYN complexes and triggers apoptotic cell death. In this preclinical study, the toxicity profiles of B43-genistein as well as unconjugated genistein were evaluated in cynomolgus monkeys. B43-genistein and genistein were administered either as single bolus injections or daily injections for 5-10 consecutive days via the i.v. route to monkeys. Neither genistein nor B43-genistein was toxic to cynomolgus monkeys, and no test article-related histopathological lesions were found in any of the two genistein-treated or five B43-genistein-treated cynomolgus monkeys. B43-genistein showed a favorable pharmacokinetics in monkeys, with a plasma half-life of 10-23 h. Plasma samples from B43-genistein-treated monkeys elicited potent and CD19 antigenspecific antileukemic activity against human CD19+ leukemia cells in vitro. To our knowledge, this is the first preclinical toxicity and pharmacokinetic study of a tyrosine kinase inhibitor-containing immunoconjugate in nonhuman primates.

In vivo biotherapy of HL-60 myeloid leukemia with a genetically engineered recombinant fusion toxin directed against the human granulocyte macrophage colony-stimulating factor receptor

Acute myeloid leukemia (AML) is the most common form of acute leukemia. Contemporary chemotherapy regimens fail to cure most patients with AML. We have genetically engineered a recombinant diphtheria toxin human granulocyte macrophage colony-stimulating factor (GMCSF) chimeric fusion protein (DTctGMCSF) that specifically targets the GMCSF receptor on fresh human AML cells and myeloid leukemia cell lines. At a nontoxic dose level, DTctGMCSF therapy was superior to the standard chemotherapeutic agents 1-beta-D-arabinofuranosylcytosine and Adriamycin, resulting in 60% long-term event-free survival of severe combined immunodeficient mice challenged with an otherwise invariably fatal cell dose of the human HL-60 myeloid leukemia. Notably, systemic exposure levels of DTctGMCSF, which were found to be therapeutic in the severe combined immunodeficient mouse xenograft model of human HL-60 myeloid leukemia, could be achieved in cynomolgus monkeys without any significant nonhematological toxicities. The recombinant DTctGMCSF fusion toxin might be useful in the treatment of AML patients whose leukemias have recurred and developed resistance to contemporary chemotherapy programs.

Hypoalgesic effect of caffeine in experimental ischemic muscle contraction pain

It has been theorized that adenosine is a leading candidate for the metabolite responsible for ischemic muscle pain. The purpose of this study was to determine the effect of the non-selective adenosine receptor antagonist, caffeine, on ischemic skeletal muscle contraction pain. Seven healthy adult volunteers with no history of pain disorders, systemic disease, or habitual caffeine use, were chosen for the two-session, cross-over, double-blind study. Every subject received either 200 mg of caffeine (NoDoz, Bristol-Myers) or identical placebo 1 hour before each of the two trials. Ischemia of the forearm was achieved by inflation of a blood pressure cuff to 250 mm Hg. Forearm muscle activity was generated by performance of wrist curis using a 5-gram bar at a rate of 40 cycles per minute. Pain was rated at 15-second intervals for 1 minute using a visual analog scale (0 to 10) with verbal descriptors. Significance was determined by univariate and multivariate analyses of variance and covariance including repeated measures. Pain ratings at 15 seconds in the caffeine trial were significantly lower (P < 0.02) than those in the placebo trial. This effect continued at 30 seconds (P < 0.05). However, by 45 seconds, pain in the caffeine trial was not significantly lower (P = 0.4) than that in the placebo trial. These results show that high-dose caffeine exhibits considerable analgesic efficacy in experimental muscle pain, adding support for a role of adenosine in producing ischemic muscle contraction pain.

Large scale manufacturing of TXU(anti-CD7)-pokeweed antiviral protein (PAP) immunoconjugate for clinical trials

We have conjugated the murine monoclonal anti-CD7 antibody TXU to the plant hemitoxin pokeweed antiviral protein (PAP) to construct an effective immunotoxin against CD7 antigen positive hematologic malignancies. The scaled-up production and purification of TXU antibody, PAP toxin, and TXU-PAP immunotoxin permitted the manufacturing of a highly purified clinical-grade TXU-PAP preparation. In clonogenic assays, TXU-PAP elicited selective and potent cytotoxicity against CD7 antigen positive human leukemia cells and killed primary clonogenic leukemic cells from T-lineage acute lymphoblastic leukemia (ALL) patients. To our knowledge, this pre-IND work represents the first effort of producing a clinical-grade PAP immunotoxin for treatment of T-lineage ALL. Since the CD7 antigen is also expressed on AML cells, TXU-PAP could also be useful for the treatment of CD7 positive acute myeloid leukemia (AML) patients.

Characterization of amylin and calcitonin receptor binding in the mouse alpha-thyroid-stimulating hormone thyrotroph cell line

Recently, a high affinity amylin binding site was identified in the mouse alpha-TSH thyrotroph cell line. In this study, we have characterized binding sites for 125I-salmon calcitonin (125I-sCT), 125I-rat alpha-calcitonin gene-related peptide (125I-CGRP), and 125I-rat amylin in alpha-TSH cells. Using 125I-CGRP or 125I-rat amylin, equilibrium was rapidly reached, and binding was fully reversible. Competition binding revealed the relative potency of peptides was sCT>amylin, CGRP>>rCT, which is similar to the specificity profile of amylin receptors characterized in rat brain. Furthermore, specific binding of 125I-rat amylin and 125I-CGRP to membrane preparations was reduced by 52% and 39%, respectively, in the presence of 20 microM GTP-gamma-s, indicating a requirement of G protein coupling for high affinity binding. In contrast, 125I-sCT binding reached equilibrium more slowly, was essentially irreversible, and was unaltered by GTP-gamma-s. Competition binding studies using 125I-sCT as radioligand demonstrated only weak interaction by CGRP or amylin, consistent with other described CT receptors. Assessment of ligand-induced cAMP accumulation and intracellular calcium signaling revealed a relative specificity profile of sCT>rCT with little or no second messenger signaling stimulated by amylin or CGRP, consistent with a C1-CT receptor phenotype. RT-PCR amplification of messenger RNA indicated that the predominant isoform was the C1a CT receptor. In cross-linking studies, 125I-rat amylin and 125I-CGRP specifically labeled a major band of relative molecular mass (Mr) approximately 80K, being approximately 10 kDa higher than the major 125I-sCT binding protein. Full deglycosylation of N-linked carbohydrates with endoglycosidase F reduced the Mr of each of the labeled proteins to approximately 50K. Cross-linked amylin or CT receptors were immunoprecipitated with C-terminally directed antimouse or antirat CT receptor antibodies but were not immunoprecipitated with nonimmune sera or antihuman CT receptor antibodies. The current data demonstrate expression of two biochemically distinct receptor phenotypes in mouse alpha-TSH cells, a CT receptor phenotype and an amylin receptor phenotype that have highly similar protein backbones.

In vivo toxicity, pharmacokinetics, and antileukemic activity of TXU (anti-CD7)-pokeweed antiviral protein immunotoxin

We evaluated the TXU (anti-CD7)-pokeweed antiviral protein (PAP) immunotoxin in both murine and nonhuman primate models. TXU-PAP caused dose-limiting cardiac toxicity in BALB/c mice. In a SCID mouse model of invariably fatal human T-lineage acute lymphoblastic leukemia (ALL), TXU-PAP therapy resulted in a marked improvement of leukemia-free survival without any side effects. Whereas 100% of control mice treated with PBS, unconjugated TXU antibody, or B43-PAP (an immunotoxin that does not react with T-lineage ALL cells) died of disseminated human leukemia within 80 days (median survival, 37 days), 80 +/- 13% of SCID mice treated with 15 microgram of TXU-PAP (median survival, >120 days) and 100% of mice treated with 30 microgram of TXU-PAP (median survival, > 120 days) remained alive and free of leukemia for >120 days. In cynomolgus monkeys, TXU-PAP showed favorable pharmacokinetics with an elimination half-life of 8.1-8.7 h. The monkeys treated with TXU-PAP at dose levels of 0.05 mg/kg/day x 5 days and 0.10 mg/kg/day x 5 days tolerated the therapy very well, without any significant clinical compromise or side effects, and at necropsy, no gross or microscopic lesions were found. This study provides a basis for further evaluation of TXU-PAP as an investigational biotherapeutic agent in the treatment of T-lineage ALL.

Pharmacokinetic features, immunogenicity, and toxicity of B43(anti-CD19)-pokeweed antiviral protein immunotoxin in cynomolgus monkeys

We studied the pharmacokinetic features, immunogenicity, and toxicity of B43-pokeweed antiviral protein (PAP) immunotoxin in 13 cynomolgus monkeys. The disposition of B43-PAP in two monkeys, when administered as a single i.v. bolus dose, was characterized by a slow clearance (1-2 ml/h/kg) with a very discrete peripheral distribution. B43-PAP was retained and distributed largely in the blood as the sole compartment with no significant equilibration with the extravascular compartment. The circulating B43-PAP immunotoxin detected in monkey plasma samples by ELISA and protein immunoblotting was both immunoreactive with, and active against, human leukemic cells in vitro. In systemic immunogenicity and toxicity studies, which involved 11 cynomolgus monkeys, each monkey received a total of seven i.v. doses of B43-PAP at a specific dose level of the dose escalation schedule. B43-PAP-treated monkeys mounted a dose-dependent humoral immune response against both the mouse IgG and PAP moieties of the immunotoxin. When administered i.v. either on an every-day or every-other-day schedule, B43-PAP was very well tolerated, with no significant clinical or laboratory signs of toxicity at total dose levels ranging from 0.007 to 0.7 mg/kg. A transient episode of a mild capillary leak with a grade 2 hypoalbuminemia and 2+ proteinuria was observed at total dose levels equal to or higher than 0.35 mg/kg. At total dose levels of 3.5 and 7.0 mg/kg, B43-PAP caused dose-limiting renal toxicity due to severe renal tubular necrosis. The present study completes the preclinical evaluation of B43-PAP and provides the basis for its clinical evaluation in children with therapy-refractory B-lineage acute lymphoblastic leukemia.

Lipoprotein-induced prostacyclin production in endothelial cells and effects of lipoprotein modification

Although lipoprotein modification has been implicated in atherogenesis, the effect of modified forms of lipoproteins on vascular cell function has not been fully resolved. We have investigated lipoprotein-induced prostaglandin production by macrovascular endothelial cells. This study delineates early responses of endothelial cells after exposure to native and modified forms of the lipoproteins. Modification of lipoproteins by oxidation or glycation significantly affected the capacity of lipoproteins to induce prostacyclin (PGI2) production by bovine aortic endothelial cells (BAEC). Modified low-density lipoprotein (LDL) increased PGI2 production in the short term (up to 24 h), but oxidized LDL caused an inhibition of PGI2-producing capacity in longer term incubations (48-72 h). Glycated (Glc) high-density lipoprotein 3 (HDL3) caused higher production of PGI2 in the short term (4-24 h) but reached similar levels as HDL3 over time. Glycation of high-density lipoprotein 2 had no effect on the PGI2-producing capacity of the lipoprotein. Thus modification of the lipoproteins affects their potential to induce PGI2 production in endothelial cells, and this may have an influence on vascular function in disease states such as diabetes and atherosclerosis. Although the changes appear to contradict data from long-term in vivo studies, these results from in vitro studies may reflect the situation in very early lesion development. GlcLDL, while causing an increase in endothelial cell PGI2 production, may be involved in compromised endothelial function, since GlcLDL is prone to oxidation.

Treatment of human B-cell precursor leukemia in SCID mice using a combination of the investigational biotherapeutic agent B43-PAP with cytosine arabinoside

Combined immunochemotherapy regimens using the investigational biotherapeutic agent B43(anti-CD19)-poke-weed antiviral protein (PAP) immunotoxin may offer an effective treatment for refractory B-cell precursor leukemias. The purpose of the present study was to explore and identify effective combinations of B43-PAP with standard chemotherapeutic drugs, including the anthracyclin doxorubicin, the epipodophyllotoxin etoposide, the nitrosurea carmustine, and the antimetabolite cytosine arabinoside. Here, we report that the B43-PAP plus cytosine arabinoside combination has potent antileukemic activity against human B-cell precursor leukemia in SCID mice and leads to 100% long-term event-free survival from an otherwise invariably fatal leukemia. Surprisingly, none of the other treatment protocols tested, including combinations of B43-PAP with carmustine, doxorubicin, or etoposide, proved more effective than B43-PAP alone.

Role of hydroxyl radicals in radiation-induced activation of lyn tyrosine kinase in human B-cell precursors

Here we show that exposure of human B-cell precursors to gamma-rays stimulates the enzymatic activity of the Src protooncogene family protein tyrosine kinase LYN. LYN activation in irradiated cells is not triggered by DNA damage or a nuclear signal since gamma-rays effectively stimulated LYN kinase in enucleated B-cell precursors as well. LYN activation in irradiated cells was abrogated by presence of the OH* radical scavenger dimethylsulfoxide and exposure of intact or enucleated B-cell precursors to chemically generated OH* radicals instead of gamma-rays also triggered LYN kinase activation and enhanced tyrosine phosphorylation of multiple electrophoretically distinct protein substrates. Thus, OH* radicals appear to be both mandatory and sufficient for radiation-induced LYN kinase activation in irradiated B-cell precursors. We further present evidence which indicates that OH* radicals activate LYN by a novel mechanism which involves disruption of inactive LYN-LYN homodimers and monomerization of the LYN kinase after proteolytic degradation of a putative LYN-associated adapter protein through a cytoplasmic TPCK-sensitive chymotrypsin-like protease following its oxidation. LYN kinase plays a pivotal role in initiation of signal cascades that affect the proliferation, differentiation, and survival of B-cell precursors. Our results prompt the hypothesis that a growth regulatory balance might be altered in human B-cell precursors by radiation-induced stimulation of LYN kinase.

In vitro and in vivo anti-leukemic efficacy of cyclic AMP modulating agents against human leukemic B-cell precursors

We show that the adenylate cyclase activating diterpine, forskolin, the phosphodiesterase inhibitor, aminophylline, and the permeant cAMP analog dibutyryl cAMP inhibit the in vitro clonogenic growth of leukemic B-cell precursors. We also used a SCID mouse xenograft model of refractory human B-cell precursor leukemia to evaluate the anti-leukemic effect of aminophylline in vivo. Treatment with aminophylline (6 mg/kg bolus followed by 0.1-0.5 mg/kg/hour x 7 days) significantly prolonged the event-free survival of SCID mice (median survival of control mice, 39 days, N = 79; median survival of aminophylline-treated mice, 60 days, N = 10; P < 0.0001 by log-rank test) and it was more effective than treatment with vincristine (median survival = 51 days, N = 5) or L asparaginase (median survival = 44 days, N = 5). However, aminophylline was not as effective as methylprednisolone (median survival: 103 days, N = 5). These results indicate that cAMP modulating agents may be useful in treatment of refractory human B-cell precursor leukemia.

Toxicity profile of the investigational new biotherapeutic agent, B43 (anti-CD19)-pokeweed antiviral protein immunotoxin

The investigational biotherapeutic agent, B43(anti-CD19)-pokeweed antiviral protein (PAP) immunotoxin, has shown substantial anti-leukemic activity in SCID mouse models of human B-lineage leukemia and lymphoma. In this report, we describe the results of a comprehensive preclinical toxicity study which determined the toxicity profile of B43-PAP in BALB/c mice. Administration of unconjugated B43 monoclonal antibody was not associated with any toxicity, whereas B43-PAP caused dose-limiting and cardiac and renal toxicities which were fatal. In addition, B43-PAP also caused multifocal skeletal myofiber necrosis, which was associated with abnormal gait and lethargy. Notably, parenteral administrations of methylprednisolone, pentoxyphylline, or dopamine were able to markedly reduce B43-PAP related toxicity. This study provides a basis for further evaluation of the toxicity of B43-PAP in monkeys and humans.

Signal transduction through the beta1 integrin family surface adhesion molecules VLA-4 and VLA-5 of human B-cell precursors activates CD19 receptor-associated protein-tyrosine kinases

We demonstrate that the CD19 receptor associates with the beta1 family integrin receptors on human B-cell precursors as well as mature B-lymphocytes, and engagement of the beta1 family integrin receptors with monoclonal antibody homoconjugates leads to rapid activation of the CD19-associated protein-tyrosine kinases (PTK) and results in hyperphosphorylation of CD19 on tyrosine residues. Our findings prompt the hypothesis that homoconjugate-induced integrin clustering may effect the approximation and, by intermolecular cross-phosphorylation, activation of the CD19-associated PTK and subsequent tyrosine phosphorylation of the CD19 receptor. The ability of the beta1 family integrin receptors to transmit a biochemical signal triggering the CD19-linked multifunctional PTK pathway provides a possible explanation for the pleiotropic biologic responses generated though adhesive VLA-4- and VLA-5-mediated contacts.

Physical and functional interactions between Lyn and p34cdc2 kinases in irradiated human B-cell precursors

Exposure of human B-cell precursors (BCP) to ionizing radiation results in cell cycle arrest at the G2-M checkpoint as a result of inhibitory tyrosine phosphorylation of p34cdc2 . Here, we show that ionizing radiation promotes physical interactions between p34cdc2 and the Src family protein-tyrosine kinase Lyn in the cytoplasm of human BCP leading to tyrosine phosphorylation of p34cdc2. Lyn kinase immunoprecipitated from lysates of irradiated BCP as well as a full-length glutathione S-transferase (GST)-Lyn fusion protein-phosphorylated recombinant human p34cdc2 on tyrosine 15. Furthermore, Lyn kinase physically associated with and tyrosine-phosphorylated p34cdc2 kinase in vivo when co-expressed in COS-7 cells. Binding experiments with truncated GST-Lyn fusion proteins suggested a functional role for the SH3 rather than the SH2 domain of Lyn in Lyn-p34cdc2 interactions in BCP. The first 27 residues of the unique amino-terminal domain of Lyn were also essential for the ability of GST-Lyn fusion proteins to bind to p34cdc2 from BCP lysates. Ionizing radiation failed to cause tyrosine phosphorylation of p34cdc2 or G2 arrest in Lyn kinase-deficient BCP, supporting an important role of Lyn kinase in radiation-induced G2 phase-specific cell cycle arrest. Our findings implicate Lyn as an important cytoplasmic suppressor of p34cdc2 function.

In vitro and in vivo antileukemic activity of B43-pokeweed antiviral protein against radiation-resistant human B-cell precursor leukemia cells

B-cell precursor (BCP) leukemia is the most common form of childhood cancer and represents one of the most radiation-resistant forms of human malignancy. In this study, we examined the antileukemic efficacy of the B43 (anti-CD19)-pokeweed antiviral protein (B43-PAP) immunotoxin against radiation-resistant BCP leukemia cells. B43-PAP caused apoptosis of radiation-resistant primary BCP leukemia cells, killed greater than 99% of radiation-resistant primary leukemic progenitor cells from BCP leukemia patients, and conferred extended survival to severe combined immunodeficiency (SCID) mice xenografted with radiation-resistant human BCP leukemia. Furthermore, the combination of B43-PAP and total body irradiation (TBI) was more effective than TBI alone in two SCID mouse bone marrow transplantation models of radiation-resistant human BCP leukemia. Thus, B43-PAP may prove useful in the treatment of radiation-resistant BCP leukemia.

Membrane-associated CD19-LYN complex is an endogenous p53-independent and Bc1-2-independent regulator of apoptosis in human B-lineage lymphoma cells

CD19 receptor is expressed at high levels on human B-lineage lymphoid cells and is physically associated with the Src protooncogene family protein-tyrosine kinase Lyn. Recent studies indicate that the membrane-associated CD19-Lyn receptor-enzyme complex plays a pivotal role for survival and clonogenicity of immature B-cell precursors from acute lymphoblastic leukemia patients, but its significance for mature B-lineage lymphoid cells (e.g., B-lineage lymphoma cells) is unknown. CD19-associated Lyn kinase can be selectively targeted and inhibited with B43-Gen, a CD19 receptor-specific immunoconjugate containing the naturally occurring protein-tyrosine kinase inhibitor genistein (Gen). We now present experimental evidence that targeting the membrane-associated CD19-Lyn complex in vitro with B43-Gen triggers rapid apoptotic cell death in highly radiation-resistant p53-Bax- Ramos-BT B-lineage lymphoma cells expressing high levels of Bcl-2 protein without affecting the Bcl-2 expression level. The therapeutic potential of this membrane-directed apoptosis induction strategy was examined in a scid mouse xenograft model of radiation-resistant high-grade human B-lineage lymphoma. Remarkably, in vivo treatment of scid mice challenged with an invariably fatal number of Ramos-BT cells with B43-Gen at a dose level < 1/10 the maximum tolerated dose resulted in 70% long-term event-free survival. Taken together, these results provide unprecedented evidence that the membrane-associated anti-apoptotic CD19-Lyn complex may be at least as important as Bcl-2/Bax ratio for survival of lymphoma cells.

Gravitational effects of the period of high tides and the new moon on lunacy

In this report, the established timing of terrestrial tidal gravity fluxes is examined to assess the role of the full moon per se in modern gravitational lunacy theory. The results show that the principal tidal gravity fluxes are semidiurnal, with lesser diurnal and even smaller fortnightly components. There are no uniquely monthly components that would correspond to the period of the full moon. This means that the gravitational effects of the new moon are equivalent to those of the full moon. Furthermore, the gravitational effects associated with the times of high tide are even greater than those associated with the moon phases. Using the technique of reductio ad absurdum, I suggest that lunacy effects, if indeed there are any, should occur twice each day (high tides) but should be more pronounced during the new moon and full moon (spring tides). On the basis of this analysis, I would recommend that all studies that have compared hospital records with the full moon be redone to coincide with the proper timing as found in this report.

An anti-CD72 immunotoxin against therapy-refractory B-lineage acute lymphoblastic leukemia

CD72 is a broadly expressed B-lineage specific surface antigen. We used J3-109(anti-CD72) monoclonal antibody to examine primary neoplastic cells from patients with acute leukemia for CD72 expression. CD72 was present at high levels in 70 of 100 B-lineage acute lymphoblastic leukemias (ALL), but it was not expressed on cells from 23 T-lineage ALL patients or 9 acute myeloblastic leukemia patients. We have prepared an anti-CD72 immunotoxin by conjugating J3-109 monoclonal antibody to the ribosome-inactivating protein, PAP.J3-109-PAP effectively killed > 99.9% of clonogenic blasts from a CD72+ B-lineage ALL cell line. We used a SCID mouse model of aggressive human pre-B ALL to evaluate the in vivo anti-leukemic efficacy of the J3-109-PAP immunotoxin. An intravenous challenge with 1 x 10(6) NALM-6-UM-1(pre-B ALL) cells caused 100% of SCID mice to die of disseminated leukemia within 41 days. Importantly, a three-day treatment with non-toxic doses of J3-109-PAP significantly improved event-free survival of SCID mice. The Kaplan-Meier estimate (+/- standard error) of the probability of event-free survival at 2 months after inoculation of NALM-6-UM-1 cells was 40 +/- 16% for SCID mice treated with a total of 15 micrograms J3-109-PAP (median survival = 58 days) as compared to 0 +/- 0% for PBS treated mice (median survival = 34 days). At 6 months after the inoculation of NALM-6-UM-1 cells, 10 +/- 9% of the J3-109-PAP treated SCID mice were still alive with no evidence of leukemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Favorable pharmacodynamic features and superior anti-leukemic activity of B43 (anti-CD19) immunotoxins containing two pokeweed antiviral protein molecules covalently linked to each monoclonal antibody molecule

Standard immunotoxin production procedures using whole IgG as the MoAb moiety yield a heterogeneous mixture of 180 kDa, 210 kDa, and 240 kDa immunotoxin species with 1 to 1, 1 to 2, and 1 to 3 MoAb to toxin ratios. This heterogeneity makes it impossible to precisely deliver a predetermined immunotoxin dose to target cells and impairs the accuracy of pharmacologic studies. In this report, we describe the preparation and characterization of B43(anti-CD19)-pokeweed antiviral protein (PAP) immunotoxins containing either one or two 30 kDa PAP toxin molecules covalently linked to each 150 kDa B43 monoclonal antibody molecule. Compared to the 180 kDa immunotoxin, the 210 kDa immunotoxin displayed greater in vitro chemical stability, resulted in higher systemic exposure levels in vivo, and was a more effective anti-leukemic agent in a SCID mouse model of human B-lineage acute lymphoblastic leukemia. Taken together, the results of this study recommend the clinical evaluation of 210 kDa B43-PAP as a potentially more effective immunotoxin against relapsed B-lineage ALL.

Biotherapy for xenografted human central nervous system leukemia in mice with severe combined immunodeficiency using B43 (anti-CD19)-pokeweed antiviral protein immunotoxin

The study of central nervous system (CNS) leukemia has been hampered by the lack of a suitable animal model. We report that severe combined immunodeficiency (SCID) mice invariably develop rapidly progressive fatal CNS leukemia within 3 weeks after intravenous injection of NALM-6 pre-B acute lymphoblastic leukemia (ALL) cells. Colonization of the dura mater and subarachnoid space, usually of the distal spinal cord with occasional extension into the Virchow-Robin spaces of blood vessels subjacent to the meninges, followed involvement of bone marrow in the skull, vertebrae, and, occasionally, the appendicular skeleton. Occult CNS leukemia was detectable by polymerase chain reaction amplification of human DNA as early as 8 days postinoculation of leukemia cells. We used this in vivo model of human CNS leukemia to examine the therapeutic efficacy and toxicity of intrathecally administered B43 (anti-CD19)-pokeweed antiviral protein (PAP), an anti-B-lineage ALL immunotoxin directed against the pan-B-cell antigen CD19/Bp95. Intrathecal therapy with B43 (anti-CD19)-PAP immunotoxin at nontoxic dose levels significantly improved survival of SCID mice and was superior to intrathecal methotrexate therapy.