ADCT-602, a Novel PBD Dimer-containing Antibody-Drug Conjugate for Treating CD22-positive Hematologic Malignancies.

Relapsed or refractory B-cell acute lymphoblastic leukemia (R/R B-ALL) and lymphomas have poor patient outcomes; novel therapies are needed. CD22 is an attractive target for antibody-drug conjugates (ADCs), being highly expressed in R/R B-ALL with rapid internalization kinetics. ADCT-602 is a novel CD22-targeting ADC, consisting of humanized mAb hLL2-C220, site specifically conjugated to the pyrrolobenzodiazepine dimer-based payload tesirine. In preclinical studies, ADCT-602 demonstrated potent, specific cytotoxicity in CD22-positive lymphomas and leukemias. ADCT-602 was specifically bound, internalized, and trafficked to lysosomes in CD22-positive tumor cells; after cytotoxin release, DNA interstrand crosslink formation persisted for 48 hours. In the presence of CD22-positive tumor cells, ADCT-602 caused bystander killing of CD22-negative tumor cells. A single ADCT-602 dose led to potent, dose-dependent, in vivo antitumor activity in subcutaneous and disseminated human lymphoma/leukemia models. Pharmacokinetic analyses (rat and cynomolgus monkey) showed excellent stability and tolerability of ADCT-602. Cynomolgus monkey B cells were efficiently depleted from circulation after one dose. Gene signature association analysis revealed IRAK1 as a potential marker for ADCT-602 resistance. Combining ADCT-602 + pacritinib was beneficial in ADCT-602-resistant cells. Chidamide increased CD22 expression on B-cell tumor surfaces, increasing ADCT-602 activity. These data support clinical testing of ADCT-602 in R/R B-ALL (NCT03698552) and CD22-positive hematologic cancers.

DSM-5 conduct disorder and symptoms in youths at high risk of psychosis in Kenya with DSM-5 mental disorders and substance use: towards integrated management.

Little is known about the prevalence of Conduct Disorder (CD) and symptoms of CD in high risk psychosis persons at both clinical and community populations in LMICs and in particular Kenya. This study aimed to document (1) the prevalence of CD diagnosis and symptoms in youth who screened positive for psychosis and (2) the associated mental disorders and substance use in the same cohort in LMIC. The sample size was 536 students who had screened positive on the Washington Early Recognition Center Affectivity and Psychosis (WERCAP) from a population of 9,742 high school, college and university students, but had not converted to a psychotic disorder. We collected data on socio-demographic characteristics and used the following tools: Economic indicators tool; the Diagnostic Interview Schedule (DIS) tool for DSM-5 diagnosis; World Health Organization (WHO) Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST). Basic descriptive statistics, chi-square test, Fisher's exact test, Pearson correlation and Poisson regression were conducted. Five percent (5%) of the respondents met the criteria for DSM-5 CD. Indeterminate CD comprised 10.1%. Male gender, all substances except hallucinogens lifetime, obsessive compulsive disorder, psychosis, agoraphobia, social phobia, drug abuse/dependence, antisocial personality disorder, oppositional defiant disorder, suicidality, WERCAP screen for bipolar disorder and WERCAP screen for schizophrenia were significantly (p < 0.05) associated with CD. Deceitfulness or theft criteria symptoms showed that CD had no significant gender difference. Criteria symptoms in aggression to people and animals, destruction of property and serious violations of rules were more common among males. Our findings suggest the need to screen for and diagnose CD, mental disorders and substance use in high risk psychosis youths in Kenya. This will inform integrated management.

Preclinical Development of ADCT-601, a Novel Pyrrolobenzodiazepine Dimer-based Antibody-drug Conjugate Targeting AXL-expressing Cancers.

AXL, a tyrosine kinase receptor that is overexpressed in many solid and hematologic malignancies, facilitates cancer progression and is associated with poor clinical outcomes. Importantly, drug-induced expression of AXL results in resistance to conventional chemotherapy and targeted therapies. Together with its presence on multiple cell types in the tumor immune microenvironment, these features make it an attractive therapeutic target for AXL-expressing malignancies. ADCT-601 (mipasetamab uzoptirine) is an AXL-targeted antibody-drug conjugate (ADC) comprising a humanized anti-AXL antibody site specifically conjugated using GlycoConnect technology to PL1601, which contains HydraSpace, a Val-Ala cleavable linker and the potent pyrrolobenzodiazepine (PBD) dimer cytotoxin SG3199. This study aimed to validate the ADCT-601 mode of action and evaluate its efficacy in vitro and in vivo, as well as its tolerability and pharmacokinetics. ADCT-601 bound to both soluble and membranous AXL, and was rapidly internalized by AXL-expressing tumor cells, allowing release of PBD dimer, DNA interstrand cross-linking, and subsequent cell killing. In vivo, ADCT-601 had potent and durable antitumor activity in a wide variety of human cancer xenograft mouse models, including patient-derived xenograft models with heterogeneous AXL expression where ADCT-601 antitumor activity was markedly superior to an auristatin-based comparator ADC. Notably, ADCT-601 had antitumor activity in a monomethyl auristatin E-resistant lung-cancer model and synergized with the PARP inhibitor olaparib in a BRCA1-mutated ovarian cancer model. ADCT-601 was well tolerated at doses of up to 6 mg/kg and showed excellent stability in vivo. These preclinical results warrant further evaluation of ADCT-601 in the clinic.

Antitumor Activity of MEDI3726 (ADCT-401), a Pyrrolobenzodiazepine Antibody-Drug Conjugate Targeting PSMA, in Preclinical Models of Prostate Cancer.

Prostate-specific membrane antigen (PSMA) is a membrane-bound glutamate carboxypeptidase that is highly expressed in nearly all prostate cancers with the highest expression in metastatic castration-resistant prostate cancer (mCRPC). The prevalence of increased surface expression and constitutive internalization of PSMA make it an attractive target for an antibody-drug conjugate (ADC) approach to treating patients with mCRPC. MEDI3726 (previously known as ADCT-401) is an ADC consisting of an engineered version of the anti-PSMA antibody J591 site specifically conjugated to the pyrrolobenzodiazepine (PBD) dimer tesirine. MEDI3726 specifically binds the extracellular domain of PSMA and, once internalized, releases the PBD dimer to crosslink DNA and trigger cell death. In vitro, MEDI3726 demonstrated potent and specific cytotoxicity in a panel of PSMA-positive prostate cancer cell lines, consistent with internalization and DNA interstrand crosslinking. In vivo, MEDI3726 showed robust antitumor activity against the LNCaP and the castration-resistant CWR22Rv1 prostate cancer cell line xenografts. MEDI3726 also demonstrated durable antitumor activity in the PSMA-positive human prostate cancer patient-derived xenograft (PDX) LuCaP models. This activity correlated with increased phosphorylated Histone H2AX in tumor xenografts treated with MEDI3726. MEDI3726 is being evaluated in a phase I clinical trial as a treatment for patients with metastatic castrate-resistant prostate cancer (NCT02991911). Mol Cancer Ther; 17(10); 2176-86. ©2018 AACR.

Lamotrigine for people with borderline personality disorder: a RCT.

BACKGROUND: No drug treatments are currently licensed for the treatment of borderline personality disorder (BPD). Despite this, people with this condition are frequently prescribed psychotropic medications and often with considerable polypharmacy. Preliminary studies have indicated that mood stabilisers may be of benefit to people with BPD. OBJECTIVE: To examine the clinical effectiveness and cost-effectiveness of lamotrigine for people with BPD. DESIGN: A two-arm, double-blind, placebo-controlled individually randomised trial of lamotrigine versus placebo. Participants were randomised via an independent and remote web-based service using permuted blocks and stratified by study centre, the severity of personality disorder and the extent of hypomanic symptoms. SETTING: Secondary care NHS mental health services in six centres in England. PARTICIPANTS: Potential participants had to be aged ≥ 18 years, meet diagnostic criteria for BPD and provide written informed consent. We excluded people with coexisting psychosis or bipolar affective disorder, those already taking a mood stabiliser, those who spoke insufficient English to complete the baseline assessment and women who were pregnant or contemplating becoming pregnant. INTERVENTIONS: Up to 200 mg of lamotrigine per day or an inert placebo. Women taking combined oral contraceptives were prescribed up to 400 mg of trial medication per day. MAIN OUTCOME MEASURES: Outcomes were assessed at 12, 24 and 52 weeks after randomisation. The primary outcome was the total score on the Zanarini Rating Scale for Borderline Personality Disorder (ZAN-BPD) at 52 weeks. The secondary outcomes were depressive symptoms, deliberate self-harm, social functioning, health-related quality of life, resource use and costs, side effects of treatment and adverse events. Higher scores on all measures indicate poorer outcomes. RESULTS: Between July 2013 and October 2015 we randomised 276 participants, of whom 195 (70.6%) were followed up 52 weeks later. At 52 weeks, 49 (36%) of those participants prescribed lamotrigine and 58 (42%) of those prescribed placebo were taking it. At 52 weeks, the mean total ZAN-BPD score was 11.3 [standard deviation (SD) 6.6] among those participants randomised to lamotrigine and 11.5 (SD 7.7) among those participants randomised to placebo (adjusted mean difference 0.1, 95% CI -1.8 to 2.0; p = 0.91). No statistically significant differences in secondary outcomes were seen at any time. Adjusted costs of direct care for those prescribed lamotrigine were similar to those prescribed placebo. LIMITATIONS: Levels of adherence in this pragmatic trial were low, but greater adherence was not associated with better mental health. CONCLUSIONS: The addition of lamotrigine to the usual care of people with BPD was not found to be clinically effective or provide a cost-effective use of resources. FUTURE WORK: Future research into the treatment of BPD should focus on improving the evidence base for the clinical effectiveness and cost-effectiveness of non-pharmacological treatments to help policy-makers make better decisions about investing in specialist treatment services. TRIAL REGISTRATION: Current Controlled Trials ISRCTN90916365. FUNDING: Funding for this trial was provided by the Health Technology Assessment programme of the National Institute for Health Research (NIHR) and will be published in full in Health Technology Assessment; Vol. 22, No. 17. See the NIHR Journals Library website for further project information. The Imperial Biomedical Research Centre Facility, which is funded by NIHR, also provided support that has contributed to the research results reported within this paper. Part of Richard Morriss' salary during the project was paid by NIHR Collaboration for Leadership in Applied Health Research and Care East Midlands.

ADCT-402, a PBD dimer-containing antibody drug conjugate targeting CD19-expressing malignancies.

Human CD19 antigen is a 95-kDa type I membrane glycoprotein in the immunoglobulin superfamily whose expression is limited to the various stages of B-cell development and differentiation and is maintained in the majority of B-cell malignancies, including leukemias and non-Hodgkin lymphomas of B-cell origin. Coupled with its differential and favorable expression profile, CD19 has rapid internalization kinetics and is not shed into the circulation, making it an ideal target for the development of antibody-drug conjugates (ADCs) to treat B-cell malignancies. ADCT-402 (loncastuximab tesirine) is a novel CD19-targeted ADC delivering SG3199, a highly cytotoxic DNA minor groove interstrand crosslinking pyrrolobenzodiazepine (PDB) dimer warhead. It showed potent and highly targeted in vitro cytotoxicity in CD19-expressing human cell lines. ADCT-402 was specifically bound, internalized, and trafficked to lysosomes in CD19-expressing cells and, following release of the PBD warhead, resulted in formation of DNA crosslinks that persisted for 36 hours. Bystander killing of CD19- cells by ADCT-402 was also observed. In vivo, single doses of ADCT-402 resulted in highly potent, dose-dependent antitumor activity in several subcutaneous and disseminated human tumor models with marked superiority to comparator ADCs delivering tubulin inhibitors. Dose-dependent DNA crosslinks and γ-H2AX DNA damage response were measured in tumors by 24 hours after single dose administration, whereas matched peripheral blood mononuclear cells showed no evidence of DNA damage. Pharmacokinetic analysis in rat and cynomolgus monkey showed excellent stability and tolerability of ADCT-402 in vivo. Together, these impressive data were used to support the clinical testing of this novel ADC in patients with CD19-expressing B-cell malignancies.

ADCT-301, a Pyrrolobenzodiazepine (PBD) Dimer-Containing Antibody-Drug Conjugate (ADC) Targeting CD25-Expressing Hematological Malignancies.

Despite the many advances in the treatment of hematologic malignancies over the past decade, outcomes in refractory lymphomas remain poor. One potential strategy in this patient population is the specific targeting of IL2R-α (CD25), which is overexpressed on many lymphoma and leukemic cells, using antibody-drug conjugates (ADC). ADCT-301 is an ADC composed of human IgG1 HuMax-TAC against CD25, stochastically conjugated through a dipeptide cleavable linker to a pyrrolobenzodiazepine (PBD) dimer warhead with a drug-antibody ratio (DAR) of 2.3. ADCT-301 binds human CD25 with picomolar affinity. ADCT-301 has highly potent and selective cytotoxicity against a panel of CD25-expressing human lymphoma cell lines. Once internalized, the released warhead binds in the DNA minor groove and exerts its potent cytotoxic action via the formation of DNA interstrand cross-links. A strong correlation between loss of viability and DNA cross-link formation is demonstrated. DNA damage persists, resulting in phosphorylation of histone H2AX, cell-cycle arrest in G2-M, and apoptosis. Bystander killing of CD25-negative cells by ADCT-301 is also observed. In vivo, a single dose of ADCT-301 results in dose-dependent and targeted antitumor activity against both subcutaneous and disseminated CD25-positive lymphoma models. In xenografts of Karpas 299, which expressed both CD25 and CD30, marked superiority over brentuximab vedotin (Adcetris) is observed. Dose-dependent increases in DNA cross-linking, γ-H2AX, and PBD payload staining were observed in tumors in vivo indicating a role as relevant pharmacodynamic assays. Together, these data support the clinical testing of this novel ADC in patients with CD25-expressing tumors. Mol Cancer Ther; 15(11); 2709-21. ©2016 AACR.

Escherichia coli-derived outer membrane vesicles are genotoxic to human enterocyte-like cells.

BACKGROUND: Colorectal cancers are the third most common type in the world. The causes of the disease are poorly understood, but since the discovery of Helicobacter pylori as a causative agent of gastric cancer, attention has turned to bacteria as a possible trigger for colorectal cancer. Recently H. pylori outer membrane vesicles (OMVs) were revealed as potentially genotoxic which can be important first step in carcinogenesis. We therefore investigated whether OMVs from intestinal Escherichia coli could be genotoxic. METHODS: OMVs from the avirulent DH5α strain, a pathogenic adherent-invasive E. coli (AIEC) and an enterohaemolytic (EHEC) strain of E. coli were enriched by ultracentrifugation. The effect on the growth and viability of human enterocyte-like Caco-2 cells by OMVs was determined by trypan blue exclusion, MTT and BrdU incorporation assays. The ability of OMVs to induce DNA damage was assayed by single-cell gel electrophoresis, and 8-oxo-dG and γH2Ax immunofluorescence staining. Cytopathological changes were assessed by microscopy. The induction of aneuploidy by the OMVs was measured by flow cytometry in Caco-2 and LoVo cells. RESULTS: We found that OMVs derived were internalised by Caco-2 cells, increased cell numbers, induced double-stranded DNA breaks, recruited γH2Ax to the nucleus, initiated DNA rereplication, and produced distended multinucleate cells. DH5α and AIEC OMVs caused free radical generation as indicated by the reduction of glutathione in cells, leading to the development of mutagenic 8-oxo-dG adducts in DNA. Flow cytometry revealed that DH5α and EHEC OMVs increased aneuploidy in p53 mutant Caco-2 cells, but not in p53 wild type LoVo cells. CONCLUSION: We conclude that E. coli derived OMVs, whether from avirulent or pathogenic strains are potentially genotoxic.

Influences of enteral nutrition upon CEACAM6 expression by intestinal epithelial cells.

Exclusive enteral nutrition is established as an initial therapy to induce remission in active Crohn's disease (CD), especially in children, but the mechanisms of action of this therapy are yet to be fully defined. CEACAM6 protein is an adhesion molecule that is up-regulated in active CD and implicated in the attachment of adherent-invasive Escherichia coli (AIEC) to the gut epithelium. Using the Caco-2 human adenocarcinoma cell line, this study showed that the incubation of human cells with a polymeric formula (PF) resulted in a dose-dependent increase in the expression of CEACAM6, and that this effect was most noticeable on the cell surface. Further investigation revealed that PF doubled the release of CEACAM6 protein by Caco-2 cells exposed to PF, and that an increase in release of soluble CEACAM6 inversely correlated with the ability of AIEC to associate with the intestinal epithelial cells. Our findings suggest that the secretion of cell surface-associated proteins acting as releasable decoys may be an aspect of the gut's innate immune response to pathogenic bacteria that is strengthened by PF in the setting of CD.

Human lactoferrin increases Helicobacter pylori internalisation into AGS cells.

Helicobacter pylori has high global infection rates and can cause other undesirable clinical manifestations such as duodenal ulcer (DU) and gastric cancer (GC). Frequencies of re-infection after therapeutic clearance and rates of DU versus GC vary geographically and differ markedly between developed and developing countries, which suggests additional factors may be involved. The possibility that, in vivo, lactoferrin (Lf) may play a subtle role in modulating micronutrient availability or bacterial internalisation with implications for disease etiology is considered. Lf is an iron binding protein produced in mammals that has antimicrobial and immunomodulatory properties. Some bacteria that regularly colonise mammalian hosts have adapted to living in high Lf environments and we investigated if this included the gastric pathogen H. pylori. We found that H. pylori was able to use iron from fully iron-saturated human Lf (hLf) whereas partially iron-saturated hLf (apo) did not increase H. pylori growth. Instead, apo-hLf increased adherence to and internalisation of bacteria into cultured epithelial cells. By increasing internalisation, we speculate that apo-human lactoferrin may contribute to H. pylori's ability to persistence in the human stomach, an observation that potentially has implications for the risk of H. pylori-associated disease.

Effects of bacterial products on enterocyte-macrophage interactions in vitro.

We describe a coculture model of a human intestinal epithelial cell line and human peripheral blood monocytes in which monocytes differentiate into cells with features of resident intestinal macrophages. Caco-2 cells are grown on the lower surface of a semipermeable filter with pore size of 3 µm (Transwells) until they differentiate into enterocytes. Peripheral-blood monocytes are added and the co-culture incubated for two days. Monocytes migrate through the pores of the membrane, come into direct contact with the basolateral surfaces of the epithelial cell monolayer, and develop characteristics of resident intestinal macrophages including downregulation of CD14 expression and reduced pro-inflammatory cytokine responses (IL-8, TNF and IL-1ß) to bacterial products. The apical application of lipopolysaccharide (LPS) and muramyl dipeptide (MDP) resulted in an increased number of integrated monocytes, but abrogated the downregulation of CD14 expression and the diminished cytokine responses. MDP also reduced tight-junctional integrity, whilst LPS had no effect. These data indicate that LPS and MDP have significant pathophysiological effects on enterocyte-monocyte interactions, and confirm other studies that demonstrate that enterocytes and their products influence monocyte differentiation. This model may be useful in providing insights into the interaction between monocytes, epithelial cells and intestinal bacteria in health and disease.

Psychotic symptoms in the general population of England--a comparison of ethnic groups (The EMPIRIC study).

BACKGROUND: There is considerable evidence that incidence of schizophrenia and other psychoses varies across ethnic groups in the UK, with particularly high rates for people of African-Caribbean origin. AIMS: The aims of this shady were to estimate in a community-based sample of people from ethnic minorities: 1) the prevalence of psychotic symptoms; and 2) risk factors for reporting psychotic symptoms. METHOD: Face-to-face interviews were carried out with a probabilistic sample of 4281 adults from six ethnic groups living in the UK. Psychotic symptoms were measured using the psychosis screening questionnaire (PSQ). RESULTS: There was a twofold higher rate of reporting psychotic symptoms on the PSQ in Black Caribbean people compared with Whites. Adjustment for demographic factors had little effect on this association. CONCLUSION: Prevalence rates of psychotic symptoms were higher in people from ethnic minorities, but were not consistent with the much higher first contact rates for psychotic disorder reported previously, particularly in Black Caribbeans.

The Dependent Personality Questionnaire (DPQ): a screening instrument for dependent personality.

BACKGROUND: There are no specific instruments for rating dependent personality, although this may be an important subject in clinical practice, where knowledge of dependent personality features may influence treatment. AIMS: To develop a simple self-rating questionnaire for dependent personality features and compare the findings in two groups, one with and one without established dependent personality disorder. METHOD: An 8-item Dependent Personality Questionnaire (DPQ) was developed and its acceptability and validity tested by administration to 30 psychiatric patients, half of whom had dependent personality disorder using clinical and research data, and the other 15 (pair-matched for age and sex) having other psychiatric diagnoses (including other personality disorders) but no dependent personality features. RESULTS: The mean score on the dependent personality questionnaire (DPQ) was 13.7 in those with dependent personality disorder and 7.5 in those without such a disorder (p < .005). The DPQ was also a good predictor of the diagnosis of dependent personality disorder, with sensitivity, specificity, predicted positive, and predicted negative accuracies of 87%. CONCLUSIONS: The results suggest that the DPQ may be a suitable screening instrument for dependent personality characteristics.

Validation and quantitation of an in vitro M-cell model.

This study has evaluated an in vitro model of the follicle-associated epithelia that overlie Peyer's patches of the small intestine. The model shares many phenotypic characteristics of M cells in vivo. Co-cultures of the human adenocarcinoma cell line Caco-2 and freshly isolated Peyer's patch cells were established. Fluorescence microscopy and quantitative image analysis were used to validate the model against known markers of M-cell phenotype. Apical expression of alkaline phosphatase was down-regulated in co-cultures and villin was re-distributed from the apical membrane to the cytoplasm. alpha5beta1 integrin was found on the apical surfaces of the monolayers and B and T lymphocytes integrated into the monolayers. Particle transport was temperature-dependent in co-cultures, indicating that a transcytotic route was responsible. This model provides opportunities to study factors that influence M-cell development, assess putative Peyer's patch targeting in oral vaccine technologies, and study intestinal uptake in vitro.