Challenges and gaps in immunosafety evaluation of therapeutics: An IQ DruSafe survey

Immunotoxicology/immunosafety science is rapidly evolving, with novel modalities and immuno-oncology among the primary drivers of new tools and technologies. The Immunosafety Working Group of IQ/DruSafe sought to better understand some of the key challenges in immunosafety evaluation, gaps in the science, and current limitations in methods and data interpretation. A survey was developed to provide a baseline understanding of the needs and challenges faced in immunosafety assessments, the tools currently being applied across the industry, and the impact of feedback received from regulatory agencies. This survey also focused on current practices and challenges in conducting the T-cell-dependent antibody response (TDAR) and the cytokine release assay (CRA). Respondents indicated that ICH S8 guidance was insufficient for the current needs of the industry portfolio of immunomodulators and novel modalities and should be updated. Other challenges/gaps identified included translation of nonclinical immunosafety assessments to the clinic, and lack of relevant nonclinical species and models in some cases. Key areas of emerging science that will add future value to immunotoxicity assessments include development of additional in vitro and microphysiological system models, as well as application of humanized mouse models. Efforts are ongoing in individual companies and consortia to address some of these gaps and emerging science.

Evaluation of NASA GEOS-ADAS modeled diurnal warming through comparisons to SEVIRI and AMSR2 SST observations

An analysis of the ocean skin Sea Surface Temperature (SST) has been included in the Goddard Earth Observing System (GEOS) - Atmospheric Data Assimilation System (ADAS), Version 5 (GEOS-ADAS). This analysis is based on the GEOS atmospheric general circulation model (AGCM) that simulates near-surface diurnal warming and cool skin effects. Analysis for the skin SST is performed along with the atmospheric state, including Advanced Very High Resolution Radiometer (AVHRR) satellite radiance observations as part of the data assimilation system. One month (September, 2015) of GEOS-ADAS SSTs were compared to collocated satellite Spinning Enhanced Visible and InfraRed Imager (SEVIRI) and Advanced Microwave Scanning Radiometer 2 (AMSR2) SSTs to examine how the GEOS-ADAS diurnal warming compares to the satellite measured warming. The spatial distribution of warming compares well to the satellite observed distributions. Specific diurnal events are analyzed to examine variability within a single day. The dependence of diurnal warming on wind speed, time of day, and daily average insolation is also examined. Overall the magnitude of GEOS-ADAS warming is similar to the warming inferred from satellite retrievals, but several weaknesses in the GEOS-AGCM simulated diurnal warming are identified and directly related back to specific features in the formulation of the diurnal warming model.

Abstract 867: ABT-165 is a first-in-class therapeutic Dual Variable Domain Immunoglobulin (DVD-IgTM) that targets DLL4 and VEGF for the treatment of cancer

The first generation anti-angiogenic drugs designed to block the VEGF/VEGFR pathway lend modest clinical benefit for cancer patients. Other than VEGF, DLL4 is the only known angiogenic factor with a haploinsufficiency phenotype, underscoring its essential role in vascular function. Indeed, both the VEGF/VEGFR and the DLL4/Notch signaling axes are known to cooperate during pathological angiogenesis. DLL4 is also implicated in VEGF-independent pathways, cancer stem cell survival, and immune suppression that could collectively contribute to tumor cell resistance. Given both intrinsic and acquired patient resistance mechanisms exist, targeting the DLL4/Notch pathway represents a unique opportunity for a combination strategy to improve upon current VEGF/VEGFR pathway inhibitor therapies. To this end, ABT-165 was developed as a first-in-class dual specific biologic using AbbVie's proprietary dual-variable domain immunoglobulin (DVD-IgTM) technology. ABT-165 is capable of simultaneously binding to DLL4 and VEGF with nanomolar affinities and blocking the cognate ligand-receptor interactions that result in the potent inhibition of DLL4-mediated Notch1 activation and VEGF-stimulated endothelial cell proliferation. ABT-165 is functionally superior in vitro compared to the combination of parental anti-VEGF and anti-DLL4 antibodies. In human tumor xenograft models, ABT-165 induced significant inhibition of tumor growth and survival benefit compared to single anti-DLL4 or anti-VEGF antibody treatments at equivalent doses. Mechanistically, this enhancement of anti-tumor efficacy is due in part to the disruption of new tumor vasculature coupled with blockade of vessel perfusion. Furthermore, ABT-165 in combination with cytotoxic chemotherapy agents induced tumor regression, which outperformed bevacizumab plus chemotherapy in both human breast and colon xenograft models. ABT-165 displays non-linear, dose-dependent pharmacokinetic profiles in mice and cynomolgus monkeys, with an apparent terminal half-life > 5 days in both species at a target saturation dose. In a GLP monkey toxicity study, ABT-165 at doses up to 200 mg/kg was well-tolerated with non-adverse treatment-related histopathology findings limited to the liver and thymus. In contrast, adverse and non-adverse findings were observed in the hearts of rats and monkeys, respectively, with an in-house proprietary anti-DLL4 antibody. Given that coupling of anti-DLL4 with anti-VEGF activities into a DVD-Ig may lend improved safety and/or efficacy profiles compared to antibodies, ABT-165 was advanced into a Phase 1 clinical trial.

Disclosures: All authors are employees of AbbVie. The design, study conduct, and financial support for this research were provided by AbbVie.

AbbVie participated in the interpretation of data, review, and approval of the publication.

Citation Format: Yingchun Li, Jonathan Hickson, Dominic Ambrosi, Deanna Haasch, Kelly Foster-Duke, Lucia Eaton, Fang Jiang, Surekha Akella, Wenqing Gao, Sherry Ralston, Jijie Gu, Susan Morgan-Lappe. ABT-165 is a first-in-class therapeutic Dual Variable Domain Immunoglobulin (DVD-IgTM) that targets DLL4 and VEGF for the treatment of cancer. [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 867.

Microscopic background changes in brains of cynomolgus monkeys

Brain sections from control cynomolgus monkeys (Macaca fascicularis) used in toxicology studies were evaluated retrospectively in order to better understand spontaneous background changes in this species. Hematoxylin and eosin-stained slides from 76 animals (38 males and 38 females) of 9 studies were examined. Eleven animals (9 males and 2 females) were each observed to have 1 to 3 findings within the brain sections examined, for a total of 19 findings. No findings were noted in the spinal cord. The most common finding was focal to multifocal perivascular infiltration of mononuclear cells, affecting the parenchyma, the meninges, or the choroid plexus. Additionally, focal gliosis was observed in 6 animals and a single focus of hemosiderin deposition (coincident with focal gliosis and mononuclear cell infiltrate) was noted in 1 animal. Most of the glial foci were composed of cells consistent with microglial cells, with or without admixed lymphocytes. All findings were of slight or minimal severity, lacked an apparent cause, and were considered incidental and of negligible biologic significance. An awareness of the spontaneous incidence of these background findings may facilitate the discernment of toxicologically relevant effects when these findings are observed.

Accelerating phylogenetics computing on the desktop: experiments with executing UPGMA in programmable logic

Having greater computational power on the desktop for processing taxa data sets has been a dream of biologists/statisticians involved in phylogenetics data analysis. Many existing algorithms have been highly optimized-one example being Felsenstein's PHYLIP code, written in C, for UPGMA and neighbor joining algorithms. However, the ability to process more than a few tens of taxa in a reasonable amount of time using conventional computers has not yielded a satisfactory speedup in data processing, making it difficult for phylogenetics practitioners to quickly explore data sets-such as might be done from a laptop computer. We discuss the application of custom computing techniques to phylogenetics. In particular, we apply this technology to speed up UPGMA algorithm execution by a factor of a hundred, against that of PHYLIP code running on the same PC. We report on these experiments and discuss how custom computing techniques can be used to not only accelerate phylogenetics algorithm performance on the desktop, but also on larger, high-performance computing engines, thus enabling the high-speed processing of data sets involving thousands of taxa.

The adolescent growth spurt of height among rural Indian boys in relation to childhood nutritional background: an 18 year longitudinal study

The Adolescent Growth Spurt (AGS) was studied in rural Hyderabad boys of 5+ years of age with known childhood nutritional background. Longitudinal data on height measurements of pre-school children available for 13 to 16 points of follow-up, during an 18 year period of study (i.e., from 1965-66 to 1983-84) were utilized for this purpose. A Preece and Baines model 1 (PB 1) function was fitted for height measurements of 323 boys aged 19-24 years in 1984. The boys were classified into three groups according to degree of under-nutrition at the age of 5+ years, using Boston reference values for height. Boys with severe height deficit at age 5+ were considered to have had a background of severe undernutrition and were referred as Group III. Boys with normal range height measurements at age 5+ were considered to have a normal nutritional background and were referred to as Group I. Group II boys had height deficits in between the above two groups and were considered to have milk to moderate undernutrition backgrounds. Group I boys had similar timing, intensity, duration of Adolescent Growth Spurt Period (AGSP) and gained a similar amount of height during puberty as did British boys. Group III boys differed significantly from British boys for AGS. They entered late into puberty, with significantly depressed intensity, but gained a similar amount of height, as a result of prolonged AGSP, which continued till 19.2 years. Thus a childhood background of undernutrition did not lead to any additional deficit in height during puberty. However, pre-pubertal height deficits were carried into adult height. The growth curves of rural Hyderabad children were parallel to the British distance height curve after 12 years of age. The mean constant height velocity curve of group I boys was superimposable on the British curve during puberty.