Abstract 395: Patient stratification and drug combination strategy based on drug response and genomic information from PDX clinical trials (PCTs)

Cancer is a heterogeneous disease with various molecular lesions and drug response profiles within the same tumor type. Patient stratification in clinical trials based on molecular features has contributed to recent success of several targeted cancer drugs on molecular aberrations such as BCR-ABL translocation in CML, Her2 amplification in breast and gastric cancers, EGFR mutations and ALK fusions in lung cancer and BRAF mutation in melanoma. However, in most cancers, the molecular features which can be used for patient stratification are not as simple as a single genetic aberration. Multiple drug resistance mechanisms caused by various mutations in cancer signaling pathways can also increase the uncertainty of clinical outcomes.

To increase the chance of success in human clinical studies, patient-derived xenograft (PDX) clinical trials (PCTs) have increasingly been used for predictive biomarker validation, resistance mechanism investigation and combination therapy selection. PDX tumor models have been demonstrated to have high correlations with human patients in tumor pathology, molecular characteristics and drug responses. Large scale PCTs have also shown consistency in results when compared to related human clinical trials.

At GenenDesign, we have established over 1000 PDX tumor models and more than 100 resistance models against various cancer drugs. Many of these PDX models have been characterized at RNA/Exome sequence, gene expression, gene copy number and hot-spot mutation levels. We carried out our PDX clinical trials by testing multiple approved drugs and clinical drug candidates such as targeted inhibitors against FGFRs, c-Met/ALK, HER2, EGFR, cell cycle regulators, Ras/Raf pathway, PI3K/Akt pathway, as well as chemotherapy drugs in biomarker-driven multi-drug multi-arm expanded PDX clinical trials. So far, we have accumulated more than 3000 efficacy data sets and associated PD samples.

Analysis of drug response and associated genomic information from PDX clinical trials yielded rich information for predictive biomarker identification and validation. At the same time, many potential resistance mechanisms were also revealed. These information can make human clinical trial better prepared, more efficient and focused. More importantly, testing of a targeted drug with multiple chemotherapies in the same models can also provide guidance on future combination selection strategy.

Citation Format: Jingjing Jiang, Tengfei Yu, Ying Yan, Wei Du, Tingting Tan, Xuqin Yang, Jiali Gu, Xin K. Ye, Zhenyu Gu. Patient stratification and drug combination strategy based on drug response and genomic information from PDX clinical trials (PCTs). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 395.

Surgical and postoperative events during permanent fistulation of sheep rumen by the Schalk and Amadon method

OBJECTIVE

To describe and report on the course of events during and after surgical fistulation of sheep rumen by the Schalk and Amadon method and on improvements to address current trends in animal health, care and welfare.

METHODS

A permanent re-entry fistula was created in 13 sheep using a method in which a fold of rumen is exteriorised and held by a metal clamp. Following surgery, sheep were monitored daily for any abnormalities for 4 weeks, then weekly for 6 months.

RESULTS

Permanent fistulation was achieved in all 13 sheep; 2 sheep had minor complications: one during the surgery (rumen perforation) and one on the day after surgery (slipping of the metal clamp), but both recovered within 48 h with treatment. Over the 4 weeks post-surgery, 7 sheep had mildly elevated rectal temperatures, which resolved with non-steroidal anti-inflammatory drugs, systemic antibiotics and/or topical antiseptic cream. There was an 8-day variation among sheep in the time from surgery to creation of the fistula.

CONCLUSION

Rumen fistulation of sheep by the Schalk and Amadon method, as described here, is a comparatively simple, safe and ethical procedure, with minimal effect on or complications for the animal.

Internet and smartphone application usage in eating disorders: A descriptive study in Singapore

Introduction

Eating disorders are associated with significant morbidity and mortality. The Internet is a popular medium for individuals with eating disorders to discuss and reinforce their affliction. However, the available literature on Internet usage and eating disorders is scarce, especially in the area of social media and smartphone application (“app”) usage.

Objectives & aims

To look at the Internet and smartphone app usage patterns of participants who presented with an eating disorder in Singapore, and whether it corresponded to severity of illness.

Methods

Individuals who presented to the Eating Disorders clinic at the Singapore General Hospital from 13th June 2013 to 20th December 2013 completed a self-reported questionnaire on Internet and app usage. They also completed the EDE-Q, EAT-26 and CIA 3.0.

Results

Fifty-five participants completed the study. A total of 41.8% had anorexia nervosa, 34.5% had bulimia nervosa, and 9.1% were ED-NOS. 41.8% felt that apps helped to perpetuate their illness, while 32.7% felt that apps were helpful for recovery. Overall, any smartphone application usage was associated with younger age and greater eating disorder psychopathology and psychosocial impairment. While 30.9% had encountered eating disorder-related content on Facebook, only 12.75 visited Facebook groups related to eating disorders. For YouTube, “Cooking and Food” and “Beauty and Fashion” videos were among the top 3 types of videos that participants watched.

Conclusions

Internet and smartphone app usage is significant, and they are used to prolong or worsen eating disorder behavior in those with greater severity of illness. It is necessary to include interventions in this aspect as part of treatment.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Altered Peripheral B-Lymphocyte Subsets in Type 1 Diabetes and Latent Autoimmune Diabetes in Adults

OBJECTIVE

B lymphocytes play an important role in the immunopathogenesis of autoimmune diabetes. We hypothesized that the altered B-cell subset phenotype is associated with autoimmune diabetes.

RESEARCH DESIGN AND METHODS

Patients with type 1 diabetes (T1D) (n = 81), latent autoimmune diabetes in adults (LADA) (n = 82), or type 2 diabetes (T2D) (n = 95) and healthy control subjects (n = 218) with normal glucose tolerance (NGT) were recruited. We determined the percentage of circulating B-lymphocyte subsets, including CD19(+)CD23(-)CD21(+) (marginal zone B [MZB]), CD19(+)CD23(+)CD21(-) (follicular B [FoB]), and CD19(+)CD5(+)CD1d(hi) (interleukin-10-producing regulatory B [B10]) cells by flow cytometry.

RESULTS

Patients with T1D or LADA had increased percentages of MZB cells and decreased percentages of FoB cells compared with healthy control subjects with NGT and patients with T2D. Moreover, patients with T1D showed the lowest frequency of B10 cells compared with patients with LADA or T2D, whereas healthy control subjects expressed the highest frequency of B10 cells. Of note, the frequency of MZB cells was negatively associated and the frequency of FoB cells was positively associated with fasting C-peptide (FCP). The frequency of B10 cells was positively correlated with FCP and negatively correlated with hemoglobin A(1c).

CONCLUSIONS

The data show that patients with T1D or LADA express an altered frequency of B-cell subsets, which is associated with islet function and glycemia. These findings suggest that B lymphocytes may be involved in loss of self-tolerance and β-cell destruction and could be used as a biomarker and potential target for immunological intervention.

Highly exposed surface area of {001} facets dominated BiOBr nanosheets with enhanced visible light photocatalytic activity

The enhanced photocatalytic activity of BiOBr nanosheets depends on the large exposed surface areas of {001} facets (S_{001}).

Transition of resistive switching behavior for a HfOx film induced by Ni doping

In this work, Ni-doped HfO_x films with different Ni doping concentrations were fabricated and the chemical bonding states as well as the resisistive switching characteristics were investigated.

Efficient l-lactic acid production from sweet sorghum bagasse by open simultaneous saccharification and fermentation

An open SSF process using B. coagulans LA1507 introduces an effective way to produce l-lactic acid from abundant SSB.

Identification of a novel cathelicidin antimicrobial peptide from ducks and determination of its functional activity and antibacterial mechanism

The family of antimicrobial peptide, cathelicidins, which plays important roles against infections in animals, has been identified from many species. Here, we identified a novel avian cathelicidin ortholog from ducks and named dCATH. The cDNA sequence of dCATH encodes a predicted 146-amino-acid polypeptide composed of a 17-residue signal peptide, a 109-residue conserved cathelin domain and a 20-residue mature peptide. Phylogenetic analysis demonstrated that dCATH is highly divergent from other avian peptides. The α-helical structure of the peptide exerted strong antimicrobial activity against a broad range of bacteria in vitro, with most minimum inhibitory concentrations in the range of 2 to 4 μM. Moreover, dCATH also showed cytotoxicity, lysing 50% of mammalian erythrocytes in the presence or absence of 10% fetal calf serum at concentrations of 32 μM or 20 μM and killing 50% HaCaT cells at a concentration of 10 μM. The effects on bacterial outer and inner membranes, as examined by scanning electron microscope and transmission electron microscopy, indicate that dCATH kills microbial cells by increasing permeability, causing a loss of membrane integrity.

Abstract 1476: Effect of target therapies in liver cancer PDX tumor models: Response, resistance and predictive biomarkers

Liver cancer is one of the leading causes of cancer mortality worldwide. Hepatocelluar carcinoma (HCC) is the most common form of liver cancer, followed by intrahepatic cholangiocarcinoma (IHCC). HCC has dismal clinical outcome, whereas the prognosis is even worse for IHCC as it is more difficult to diagnose and to treat comparing to HCC. Surgical resection and local ablation remain the top choices of therapy for early liver cancer while chemoembolization-TACE is commonly used to treat intermediate HCC. Sorafenib is the only FDA approved target therapy for advanced HCC and its clinical utility in IHCC is still being examined in clinical trials. On-going clinical trials are also testing therapeutic modalities against oncogenic pathways including RTK signaling pathways, PI3K/Ras pathways and the angiogenesis pathway.

PDX tumor models recapitulate the clinical complexity of the original human cancers. At GenenDesign, we have established over 800 PDX tumor models and conducted extensive drug response tests in a mouse trial format. GenenDesign liver cancer PDX tumor panel comprises of 36 HCC and over 10 IHCC models. Our in-house mouse trials in liver PDX tumor models include treatment with sorafenib as well as XL184, a multi-kinase inhibitor currently being evaluated in clinical trials. In addition, crizotinib (a cMET inhibitor) and AZD4547 (an FGFR inhibitor) as mono-therapies as well as in combination with sorafenib are also tested in search of therapeutic signals. From these studies, we have identified both drug sensitive and de novo drug resistant models. Through long-term treatment, acquired resistance models and reversible resistance models are also established.

Currently, GD liver cancer PDX tumors are being analyzed by genetic and genomic profiling (hot-spot mutational analysis, exome-seq, RNA-seq, SNP array and gene expression array). Bioinformatics analysis is on-going to identify genomic signatures with the potential as predictive biomarkers for sorafenib and other targeted therapies in liver cancer. Together with genomic profiling, signal search in PDX mouse trials promise to be effective in generating preclinical datasets to facilitate clinical trial designs.

Citation Format: Tengfei Yu, Ying Yan, Wei Du, Liang Hua, Xuqin Yang, Tingting Tan, Jiali Gu, Jingjing Jiang, Xin K. Ye, Zhenyu Gu. Effect of target therapies in liver cancer PDX tumor models: Response, resistance and predictive biomarkers. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1476. doi:10.1158/1538-7445.AM2015-1476

Abstract 3222: Biomarker discovery through bioinformatic analysis of genomic profiles of PDX models with different responses to cancer therapies

Patient derived xenograft (PDX) tumor models have been proved to recapitulate the complexity and heterogeneity of their corresponding human tumors by phenotypic and genomic characterization, and thus become to be widely used in recent years in preclinical setting to facilitate drug discovery, translational studies and clinical trials support. Results from increasing number of preclinical studies, especially mouse trials, with PDX models in the past several years, have also demonstrated close correlation between drug response profiles with PDX models and clinical outcomes.

GenenDesign has established over 800 PDX tumor models and derived around 100 resistance models to drugs of interest. Genomic profiling data of PDX models are acquired at hot-spot mutation, gene expression, gene copy number and RNA/Exome sequence levels. Through our in-house efforts, PDX models of different tumor types were tested with related SOCs and clinical candidates in biomarker-driven multi-drug multi-arm clinical trial settings. So far, more than 1200 data sets have been generated, including responses to targeted inhibitors against HER2, EGFR, FGFRs, c-Met/ALK, cell cycle regulators, Ras/Raf pathway, PI3K/Akt pathway, epigenetic targets, as well as chemotherapy drugs.

In this study, we use bioinformatic tools to compare the genomic profiles of NSCLC PDX models based on their response profiles to multiple chemotherapy drugs. Biomarker signatures associated with SOC treatment sensitivity or resistance are revealed from bioinformatic analysis and being tested with both new NSCLC PDX models and clinical cohorts.

The combination of genomic profiles and drug response information to multiple chemo/targeted therapies of over 800 PDX models at GenenDesign would help biomarker discovery for companion diagnosis to meet the increasing needs for precision medicine.

Citation Format: Jingjing Jiang, Tengfei Yu, Ying Yan, Wei Du, Tingting Tan, Xuqin Yang, Jiali Gu, Liang Hua, Katherine Xin Ye, Zhenyu Gu. Biomarker discovery through bioinformatic analysis of genomic profiles of PDX models with different responses to cancer therapies. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 3222. doi:10.1158/1538-7445.AM2015-3222

Transformation of truncated gold octahedrons into triangular nanoprisms through the heterogeneous nucleation of silver

Described is a straightforward procedure for forming organized substrate-immobilized nanoprisms which are single crystalline, surfactant-free and which form a heteroepitaxial relationship with the underlying substrate. The devised route utilizes truncated Au octahedrons formed through solid state dewetting techniques as high temperature heterogeneous nucleation sites for Ag adatoms which are arriving to the substrate surface in the vapour phase. Observed is a morphological and compositional transformation of the Au structures to triangular nanoprisms comprised of a homogeneous AuAg alloy. During this transformation, the localized surface plasmon resonance red-shifts, broadens and increases in strength. The shape transformation, which cannot be rationalized using thermodynamic arguments dependent on the surface energy minimization, is described in terms of a kinetically driven growth mode, previously predicted by molecular dynamic simulations. The so-formed structures, when coated with a thin layer of Pd, are demonstrated as plasmonic sensing elements for hydrogen detection.