Review of Russian language studies on radionuclide behaviour in agricultural animals: Transfer to animal tissues

Data on radionuclide transfer to animals from research performed in the former Soviet Union were reviewed to collate transfer coefficient values (F_f) to animal tissues such as liver, kidney and bone, but not muscle which has previously been reported. The derived values were compared with selected data published in the English language literature. The new data are mainly for ⁹⁰Sr and ¹³⁷Cs, although some data were also provided for ³H, ⁵⁴Mn, ⁵⁹Fe, ⁶⁰Co, ²²Na ⁶⁵Zn, ¹³¹I and U. The Russian language data may provide a basis for better informed evaluation of radiation dose from the consumption of such animal products, which can form important components of the diet in some countries.

A Phase II Study of Pembrolizumab in EGFR-Mutant, PD-L1+, Tyrosine Kinase Inhibitor Naïve Patients With Advanced NSCLC

BACKGROUND

Despite the significant antitumor activity of pembrolizumab in NSCLC, clinical benefit has been less frequently observed in patients whose tumors harbor EGFR mutations compared to EGFR wild-type patients. Our single-center experience on the KEYNOTE-001 trial suggested that pembrolizumab-treated EGFR-mutant patients, who were tyrosine kinase inhibitor (TKI) naïve, had superior clinical outcomes to those previously treated with a TKI. As TKI naïve EGFR-mutants have generally been excluded from pembrolizumab studies, data to guide treatment decisions in this patient population is lacking, particularly in patients with programmed death ligand 1 (PD-L1) expression ≥50%.

METHODS

We conducted a phase II trial (NCT02879994) of pembrolizumab in TKI naive patients with EGFR mutation-positive, advanced NSCLC and PD-L1-positive (≥1%, 22C3 antibody) tumors. Pembrolizumab was administered 200 mg every 3 weeks. The primary endpoint was objective response rate. Secondary endpoints included safety of pembrolizumab, additional pembrolizumab efficacy endpoints, and efficacy and safety of an EGFR TKI after pembrolizumab.

RESULTS

Enrollment was ceased due to lack of efficacy after 11 of 25 planned patients were treated. Eighty-two percent of trial patients were treatment naïve, 64% had sensitizing EGFR mutations, and 73% had PD-L1 expression ≥50%. Only 1 patient had an objective response (9%), but repeat analysis of this patient's tumor definitively showed the original report of an EGFR mutation to be erroneous. Observed treatment-related adverse events were similar to prior experience with pembrolizumab, but two deaths within 6 months of enrollment, including one attributed to pneumonitis, were of concern.

CONCLUSIONS

Pembrolizumab's lack of efficacy in TKI naïve, PD-L1+, EGFR-mutant patients with advanced NSCLC, including those with PD-L1 expression ≥50%, suggests that it is not an appropriate therapeutic choice in this setting.

Abstract P5-05-05: Patient-derived triple negative breast cancer xenografts as a translational model to screen for novel kinase pathways

Overall, triple negative breast cancers (TNBCs) constitute 12% of all breast cancers, and is approximately twice more prevalent in African-American populations. Louisiana has a high proportion of African-American residents (32.5% in 2015), and thus hosts a higher population of TNBC patients. TNBCs have an aggressive phenotype that is elusive to the targeted therapeutics used to treat other breast cancer subtypes. Certain kinase families have been extensively studied as regulators of epithelial-mesenchymal transition (EMT), a process involved in the initiation of cancer metastasis. Discovery of novel kinase targets within the subset of uncharacterized kinases could provide important insight into future targeted therapies. However, current models utilized in target discovery research are limited by the inability to accurately recapitulate the complex stromal architecture and heterogenous genetic and molecular composition of breast cancer. Furthermore, immortalized cell lines are limited to a 2D environment and over time acquire mutations that may not reflect the primary tumor. Recently, our laboratory has successfully established two TNBC patient-derived xenograft (PDX) models derived from African-American patients, and generated cell lines (TU-BCx-2K1, TU-BCx-2O0) and mammospheres. One of these models, 2O0, presents tumor architecture, cellular composition, genomic (qRT-PCR) and protein (western blot) expressions that are concordant with a claudin-low subtype, which has higher rates of metastasis and recurrence. Furthermore, we show that both TNBC models metastasize to the lungs, and exhibit molecular characteristics consistent with mesenchymal phenotypes. We utilized these translational PDX models to screen a library of small molecule inhibitors that represent a variety of kinase pathways to identify novel therapeutic targets and/or pathways that are specific to TNBC subtypes. We found in a preliminary cell morphology screen using three TNBC cell lines (MDA-MB-231, BT549, MDA-MB-157), two small molecule inhibitors that increased epithelial marker (CDH1) gene expression, suppressed mesenchymal (VIM, c-FOS, SNAI1, ZEB1) expression and/or suppressed cellular motility in transwell migration assays. We observed after ex vivo treatments with our PDX tumors the two compounds increase the epithelial marker CDH1 expression, and suppress mesenchymal markers (VIM, MMP2, c-FOS, SNAI1, ZEB1) expressions. We confirm these findings in the TU-BCx-2K1 cell line. Kinase array data revealed candidate kinases responsible for the observed EMT changes in the two compounds of interest (NEK5, NEK9, NEK1 potentially affect cell motility; SRC-family kinases, TAOK2, STK10 potentially affect EMT gene changes); we plan to utilize the PDX cell lines to characterize these kinases in EMT. We aim to ultimately discover novel therapeutic targets specific to different TNBC molecular subtypes.

Citation Format: Matossian M, Burks H, Bowles A, Sabol R, Hoang V, Elliott S, Bunnell B, Zuercher W, Drewry D, Wells C, Alfortish A, Lee S, Hartono A, Jones S, Moroz K, Zea A, Burow M, Collins-Burow B. Patient-derived triple negative breast cancer xenografts as a translational model to screen for novel kinase pathways [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-05-05.

Assessment and manifestation of central sensitisation across different chronic pain conditions

Different neuroplastic processes can occur along the nociceptive pathways and may be important in the transition from acute to chronic pain and for diagnosis and development of optimal management strategies. The neuroplastic processes may result in gain (sensitisation) or loss (desensitisation) of function in relation to the incoming nociceptive signals. Such processes play important roles in chronic pain, and although the clinical manifestations differ across condition processes, they share some common mechanistic features. The fundamental understanding and quantitative assessment of particularly some of the central sensitisation mechanisms can be translated from preclinical studies into the clinic. The clinical perspectives are implementation of such novel information into diagnostics, mechanistic phenotyping, prevention, personalised treatment, and drug development. The aims of this paper are to introduce and discuss (1) some common fundamental central pain mechanisms, (2) how they may translate into the clinical signs and symptoms across different chronic pain conditions, (3) how to evaluate gain and loss of function using quantitative pain assessment tools, and (4) the implications for optimising prevention and management of pain. The chronic pain conditions selected for the paper are neuropathic pain in general, musculoskeletal pain (chronic low back pain and osteoarthritic pain in particular), and visceral pain (irritable bowel syndrome in particular). The translational mechanisms addressed are local and widespread sensitisation, central summation, and descending pain modulation.

Significance

Central sensitisation is an important manifestation involved in many different chronic pain conditions. Central sensitisation can be different to assess and evaluate as the manifestations vary from pain condition to pain condition. Understanding central sensitisation may promote better profiling and diagnosis of pain patients and development of new regimes for mechanism based therapy. Some of the mechanisms underlying central sensitisation can be translated from animals to humans providing new options in development of therapies and profiling drugs under development.

Availability and approval of cannabis-based medicines for chronic pain management and palliative/supportive care in Europe: A survey of the status in the chapters of the European Pain Federation

BACKGROUND

There is considerable public and political interest in the use of cannabis products for medical purposes.

METHODS

The task force of the European Pain Federation (EFIC) conducted a survey with its national chapters representatives on the status of approval of all types of cannabis-based medicines, the covering of costs and the availability of a position paper of a national medical association on the use of medical cannabis for chronic pain and for symptom control in palliative/supportive care.

RESULTS

Thirty-one out of 37 contacted councillors responded. Plant-derived tetrahydrocannabinol/cannabidiol (THC/CBD) oromucosal spray is approved for spasticity in multiple sclerosis refractory to conventional treatment in 21 EFIC chapters. Plant-derived THC (dronabinol) is approved for some palliative care conditions in four EFIC chapters. Synthetic THC analogue (nabilone) is approved for chemotherapy-associated nausea and vomiting refractory to conventional treatment in four EFIC chapters'. Eight EFIC chapters' countries have an exceptional and six chapters an expanded access programme for medical cannabis. German and Israeli pain societies recommend the use of cannabis-based medicines as third-line drug therapies for chronic pain within a multicomponent approach. Conversely, the German medical association and a team of finish experts and officials do not recommend the prescription of medical cannabis due to the lack of high-quality evidence of efficacy and the potential harms.

CONCLUSIONS

There are marked differences between the countries represented in EFIC in the approval and availability of cannabis-based products for medical use. EFIC countries are encouraged to collaborate with the European Medicines Agency to publish a common document on cannabis-based medicines.

SIGNIFICANCE

There are striking differences between European countries in the availability of plant-derived and synthetic cannabinoids and of medical cannabis for pain management and for symptom control in palliative care and in the covering of costs by health insurance companies or state social security systems.

Defining low anterior resection syndrome: a systematic review of the literature

AIM

There is increasing awareness of the poor functional outcome suffered by many patients after sphincter-preserving rectal resection, termed 'low anterior resection syndrome' (LARS). There is no consensus definition of LARS and varying instruments have been employed to measure functional outcome, complicating research into prevalence, contributing factors and potential therapies. We therefore aimed to describe the instruments and outcome measures used in studies of bowel dysfunction after low anterior resection and identify major themes used in the assessment of LARS.

METHOD

A systematic review of the literature was performed for studies published between 1986 and 2016. The instruments and outcome measures used to report bowel function after low anterior resection were extracted and their frequency of use calculated.

RESULTS

The search revealed 128 eligible studies. These employed 18 instruments, over 30 symptoms, and follow-up time periods from 4 weeks to 14.6 years. The most frequent follow-up period was 12 months (48%). The most frequently reported outcomes were incontinence (97%), stool frequency (80%), urgency (67%), evacuatory dysfunction (47%), gas-stool discrimination (34%) and a measure of quality of life (80%). Faecal incontinence scoring systems were used frequently. The LARS score and the Bowel Function Instrument (BFI) were used in only nine studies.

CONCLUSION

LARS is common, but there is substantial variation in the reporting of functional outcomes after low anterior resection. Most studies have focused on incontinence, omitting other symptoms that correlate with patients' quality of life. To improve and standardize research into LARS, a consensus definition should be developed, and these findings should inform this goal.

Improving the quantity, quality and transparency of data used to derive radionuclide transfer parameters for animal products. 2. Cow milk

Under the International Atomic Energy Agency (IAEA) MODARIA (Modelling and Data for Radiological Impact Assessments) Programme, there has been an initiative to improve the derivation, provenance and transparency of transfer parameter values for radionuclides from feed to animal products that are for human consumption. A description of the revised MODARIA 2016 cow milk dataset is described in this paper. As previously reported for the MODARIA goat milk dataset, quality control has led to the discounting of some references used in IAEA's Technical Report Series (TRS) report 472 (IAEA, 2010). The number of Concentration Ratio (CR) values has been considerably increased by (i) the inclusion of more literature from agricultural studies which particularly enhanced the stable isotope data of both CR and F_m and (ii) by estimating dry matter intake from assumed liveweight. In TRS 472, the data for cow milk were 714 transfer coefficient (F_m) values and 254 CR values describing 31 elements and 26 elements respectively. In the MODARIA 2016 cow milk dataset, F_m and CR values are now reported for 43 elements based upon 825 data values for F_m and 824 for CR. The MODARIA 2016 cow milk dataset F_m values are within an order of magnitude of those reported in TRS 472. Slightly bigger changes are seen in the CR values, but the increase in size of the dataset creates greater confidence in them. Data gaps that still remain are identified for elements with isotopes relevant to radiation protection.

Drug-resistant tuberculosis clinical trials: proposed core research definitions in adults

Drug-resistant tuberculosis (DR-TB) is a growing public health problem, and for the first time in decades, new drugs for the treatment of this disease have been developed. These new drugs have prompted strengthened efforts in DR-TB clinical trials research, and there are now multiple ongoing and planned DR-TB clinical trials. To facilitate comparability and maximise policy impact, a common set of core research definitions is needed, and this paper presents a core set of efficacy and safety definitions as well as other important considerations in DR-TB clinical trials work. To elaborate these definitions, a search of clinical trials registries, published manuscripts and conference proceedings was undertaken to identify groups conducting trials of new regimens for the treatment of DR-TB. Individuals from these groups developed the core set of definitions presented here. Further work is needed to validate and assess the utility of these definitions but they represent an important first step to ensure there is comparability in clinical trials on multidrug-resistant TB.

Improving the quantity, quality and transparency of data used to derive radionuclide transfer parameters for animal products. 1. Goat milk

Under the MODARIA (Modelling and Data for Radiological Impact Assessments Programme of the International Atomic Energy Agency), there has been an initiative to improve the derivation, provenance and transparency of transfer parameter values for radionuclides. The approach taken for animal products is outlined here and the first revised table for goat milk is provided. Data from some references used in TRS 472 were removed and reasons given for removal. Particular efforts were made to improve the number of CR (concentration ratio) values which have some advantages over transfer coefficients. There is little difference in most of the new CR and Fm (transfer coefficient) values for goat milk compared with those in TRS 472. In TRS 472, 21 CR values were reported for goat milk. In the 2015 dataset for goat milk CR values for a further 14 elements are now included. The CR and Fm values for only one element (Co) were removed.

Radionuclide biological half-life values for terrestrial and aquatic wildlife

The equilibrium concentration ratio is typically the parameter used to estimate organism activity concentrations within wildlife dose assessment tools. Whilst this is assumed to be fit for purpose, there are scenarios such as accidental or irregular, fluctuating, releases from licensed facilities when this might not be the case. In such circumstances, the concentration ratio approach may under- or over-estimate radiation exposure depending upon the time since the release. To carrying out assessments for such releases, a dynamic approach is needed. The simplest and most practical option is representing the uptake and turnover processes by first-order kinetics, for which organism- and element-specific biological half-life data are required. In this paper we describe the development of a freely available international database of radionuclide biological half-life values. The database includes 1907 entries for terrestrial, freshwater, riparian and marine organisms. Biological half-life values are reported for 52 elements across a range of wildlife groups (marine = 9, freshwater = 10, terrestrial = 7 and riparian = 3 groups). Potential applications and limitations of the database are discussed.