Assessing the utility of common arguments used in expert review of in silico predictions as part of ICH M7 assessments.

Expert review of two predictions, made by complementary (quantitative) structure-activity relationship models, to an overall conclusion is a key component of using in silico tools to assess the mutagenic potential of impurities as part of the ICH M7 guideline. In lieu of a specified protocol, numerous publications have presented best practise guides, often indicating the occurrence of common prediction scenarios and the evidence required to resolve them. A semi-automated expert review tool has been implemented in Lhasa Limited's Nexus platform following collation of these common arguments and assignment to the associated prediction scenarios made by Derek Nexus and Sarah Nexus. Using datasets primarily donated by pharmaceutical companies, an automated analysis of the frequency these prediction scenarios occur, and the likelihood of the associated arguments assigning the correct resolution, could then be conducted. This article highlights that a relatively small number of common arguments may be used to accurately resolve many prediction scenarios to a single conclusion. The use of a standardised method of argumentation and assessment of evidence for a given impurity is proposed to improve the efficiency and consistency of expert review as part of an ICH M7 submission.

Use of less-than-lifetime (LTL) durational limits for nitrosamines: Case study of N-Nitrosodiethylamine (NDEA).

The ICH M7(R1) guideline describes a framework to assess the carcinogenic risk of mutagenic and carcinogenic pharmaceutical impurities following less-than-lifetime (LTL) exposures. This LTL framework is important as many pharmaceuticals are not administered for a patient's lifetime and as clinical trials typically involve LTL exposures. While there has been regulatory caution about applying LTL concepts to cohort of concern (COC) impurities such as N-nitrosamines, ICH M7 does not preclude this and indeed literature data suggests that the LTL framework will be protective of patient safety for N-nitrosamines. The goal was to investigate if applying the LTL framework in ICH M7 would control exposure to an acceptable excess cancer risk in humans. Using N-nitrosodiethylamine as a case study, empirical data correlating exposure duration (as a percentage of lifespan) and cancer incidence in rodent bioassays indicate that the LTL acceptable intake (AI) as derived using the ICH M7 framework would not exceed a negligible additional risk of cancer. Therefore, controlling N-nitrosamines to an LTL AI based on the ICH M7 framework is thus demonstrated to be protective for potential carcinogenic risk to patients over the exposure durations typical of clinical trials and many prescribed medicines.

Calculating qualified non-mutagenic impurity levels: Harmonization of approaches.

The presence of impurities in drugs is unavoidable. As impurities offer no direct benefit to the patient, it is critical that impurities do not compromise patient safety. Current guidelines on the derivation of acceptable impurity levels leave aspects of calculations open for interpretation, resulting in inconsistencies across industry and regulators. To understand current impurity qualification practices from a safety standpoint, regulatory expectations and the safety risk that impurities pose, the IQ DruSafe Impurities Working Group (WG) conducted a pharmaceutical industry-wide survey. Survey results highlighted areas that could benefit from harmonization, including nonclinical species/sex selection and the application of adjustment factors (i.e., body surface area). Recommendations for alignment on these topics is included in this publication. Additionally, the WG collated repeat-dose toxicity information for 181 starting materials and intermediates, reflective of pharmaceutical impurities, to understand the toxicological risks they generally pose in relation to the drug substance (DS) and the assumptions surrounding the calculation of qualified impurity levels. An evaluation of this dataset and the survey were used to harmonize how to calculate a safe limit for an impurity based on toxicology testing of the impurity when present within the DS.

PI3K isoform-selective inhibition in neuron-specific PTEN-deficient mice rescues molecular defects and reduces epilepsy-associated phenotypes.

Epilepsy affects all ages, races, genders, and socioeconomic groups. In about one third of patients, epilepsy is uncontrolled with current medications, leaving a vast need for improved therapies. The causes of epilepsy are diverse and not always known but one gene mutated in a small subpopulation of patients is phosphatase and tensin homolog (PTEN). Moreover, focal cortical dysplasia, which constitutes a large fraction of refractory epilepsies, has been associated with signaling defects downstream of PTEN. So far, most preclinical attempts to reverse PTEN deficiency-associated neurological deficits have focused on mTOR, a signaling hub several steps downstream of PTEN. Phosphoinositide 3-kinases (PI3Ks), by contrast, are the direct enzymatic counteractors of PTEN, and thus may be alternative treatment targets. PI3K activity is mediated by four different PI3K catalytic isoforms. Studies in cancer, where PTEN is commonly mutated, have demonstrated that inhibition of only one isoform, p110ß, reduces progression of PTEN-deficient tumors. Importantly, inhibition of a single PI3K isoform leaves critical functions of general PI3K signaling throughout the body intact. Here, we show that this disease mechanism-targeted strategy borrowed from cancer research rescues or ameliorates neuronal phenotypes in male and female mice with neuron-specific PTEN deficiency. These phenotypes include cell signaling defects, protein synthesis aberrations, seizures, and cortical dysplasia. Of note, p110ß is also dysregulated and a promising treatment target in the intellectual disability Fragile X syndrome, pointing towards a shared biological mechanism that is therapeutically targetable in neurodevelopmental disorders of different etiologies. Overall, this work advocates for further assessment of p110ß inhibition not only in PTEN deficiency-associated neurodevelopmental diseases but also other brain disorders characterized by defects in the PI3K/mTOR pathway.

A new frontier in pelvic fracture pain control in the ED: Successful use of the pericapsular nerve group (PENG) block.

The pericapsular nerve group (PENG) block is a novel ultrasound-guided regional anesthesia technique derived from recent anatomic studies detailing the sensory innervation of the hip. Targeting these terminal sensory branches, the PENG block was originally developed as a potentially more effective block for perioperative hip fracture anesthesia, with the added benefit of preserving motor function. Subsequent research with higher volumes of local anesthetic demonstrated the successful utilization of PENG block for perioperative acetabular fractures. This raises the possibility that the PENG block may have a role in the Emergency Department (ED) where regional anesthesia options for pelvic fractures are lacking. Herein, we present the first description of PENG blocks successfully used for pelvic fractures in the ED setting.

Skin sensitization in silico protocol.

The assessment of skin sensitization has evolved over the past few years to include in vitro assessments of key events along the adverse outcome pathway and opportunistically capitalize on the strengths of in silico methods to support a weight of evidence assessment without conducting a test in animals. While in silico methods vary greatly in their purpose and format; there is a need to standardize the underlying principles on which such models are developed and to make transparent the implications for the uncertainty in the overall assessment. In this contribution, the relationship between skin sensitization relevant effects, mechanisms, and endpoints are built into a hazard assessment framework. Based on the relevance of the mechanisms and effects as well as the strengths and limitations of the experimental systems used to identify them, rules and principles are defined for deriving skin sensitization in silico assessments. Further, the assignments of reliability and confidence scores that reflect the overall strength of the assessment are discussed. This skin sensitization protocol supports the implementation and acceptance of in silico approaches for the prediction of skin sensitization.

Experiences of Serving and Ex-Serving Members With the PTSD Coach Australia App: Mixed Methods Study.

BACKGROUND: PTSD Coach Australia is an app for serving and ex-serving defense members and was adapted for the Australian context in 2013 from PTSD Coach, which was created in the United States. OBJECTIVE: This study aimed to provide a user-centered evaluation of the app from the perspective of serving and ex-serving members of the Australian Defence Force. METHODS: Qualitative data were collected in response to questions to participants in 1 of 5 workshops (n=29) or in telephone interviews (n=24). Quantitative data were collected using the user version of Mobile Apps Rating Scale (uMARS). RESULTS: Analysis of the qualitative data demonstrated mixed support for the app. While some people found it extremely useful, especially as an adjunct to therapy, others pointed out limitations and cautioned against the app potentially triggering symptoms in people with PTSD. This perceived risk was usually found to stem from frustration with the app's functionality rather than its content. Participants spoke about the helpful and unhelpful aspects of the app and barriers to its use and made suggestions for improvement. Many participants encouraged its continued use and highlighted the need for it to be promoted more broadly, as many were not aware of it until they were invited to participate in this research. CONCLUSIONS: PTSD Coach Australia was seen in a positive light by some participants, but others thought it had too much text and the potential to trigger a traumatic response in users with PTSD. A need to update the app was also a common comment as was the need to increase awareness of the app's existence.

MicroRNA inhibition upregulates hippocampal A-type potassium current and reduces seizure frequency in a mouse model of epilepsy.

Epilepsy is often associated with altered expression or function of ion channels. One example of such a channelopathy is the reduction of A-type potassium currents in the hippocampal CA1 region. The underlying mechanisms of reduced A-type channel function in epilepsy are unclear. Here, we show that inhibiting a single microRNA, miR-324-5p, which targets the pore-forming A-type potassium channel subunit Kv4.2, selectively increased A-type potassium currents in hippocampal CA1 pyramidal neurons in mice. Resting membrane potential, input resistance and other potassium currents were not altered. In a mouse model of acquired chronic epilepsy, inhibition of miR-324-5p reduced the frequency of spontaneous seizures and interictal epileptiform spikes supporting the physiological relevance of miR-324-5p-mediated control of A-type currents in regulating neuronal excitability. Mechanistic analyses demonstrated that microRNA-induced silencing of Kv4.2 mRNA is increased in epileptic mice leading to reduced Kv4.2 protein levels, which is mitigated by miR-324-5p inhibition. By contrast, other targets of miR-324-5p were unchanged. These results suggest a selective miR-324-5p-dependent mechanism in epilepsy regulating potassium channel function, hyperexcitability and seizures.

Extending (Q)SARs to incorporate proprietary knowledge for regulatory purposes: is aromatic N-oxide a structural alert for predicting DNA-reactive mutagenicity?

(Quantitative) structure-activity relationship or (Q)SAR predictions of DNA-reactive mutagenicity are important to support both the design of new chemicals and the assessment of impurities, degradants, metabolites, extractables and leachables, as well as existing chemicals. Aromatic N-oxides represent a class of compounds that are often considered alerting for mutagenicity yet the scientific rationale of this structural alert is not clear and has been questioned. Because aromatic N-oxide-containing compounds may be encountered as impurities, degradants and metabolites, it is important to accurately predict mutagenicity of this chemical class. This article analysed a series of publicly available aromatic N-oxide data in search of supporting information. The article also used a previously developed structure-activity relationship (SAR) fingerprint methodology where a series of aromatic N-oxide substructures was generated and matched against public and proprietary databases, including pharmaceutical data. An assessment of the number of mutagenic and non-mutagenic compounds matching each substructure across all sources was used to understand whether the general class or any specific subclasses appear to lead to mutagenicity. This analysis resulted in a downgrade of the general aromatic N-oxide alert. However, it was determined there were enough public and proprietary data to assign the quindioxin and related chemicals as well as benzo[c][1,2,5]oxadiazole 1-oxide subclasses as alerts. The overall results of this analysis were incorporated into Leadscope's expert-rule-based model to enhance its predictive accuracy.

Principles and procedures for handling out-of-domain and indeterminate results as part of ICH M7 recommended (Q)SAR analyses.

The International Council for Harmonization (ICH) M7 guideline describes a hazard assessment process for impurities that have the potential to be present in a drug substance or drug product. In the absence of adequate experimental bacterial mutagenicity data, (Q)SAR analysis may be used as a test to predict impurities' DNA reactive (mutagenic) potential. However, in certain situations, (Q)SAR software is unable to generate a positive or negative prediction either because of conflicting information or because the impurity is outside the applicability domain of the model. Such results present challenges in generating an overall mutagenicity prediction and highlight the importance of performing a thorough expert review. The following paper reviews pharmaceutical and regulatory experiences handling such situations. The paper also presents an analysis of proprietary data to help understand the likelihood of misclassifying a mutagenic impurity as non-mutagenic based on different combinations of (Q)SAR results. This information may be taken into consideration when supporting the (Q)SAR results with an expert review, especially when out-of-domain results are generated during a (Q)SAR evaluation.

Managing emerging mutagenicity risks: Late stage mutagenic impurity control within the atovaquone second generation synthesis.

The mutagenic-impurity control strategy for a second generation manufacturing route to the non-mutagenic antipneumocystic agent atovaquone (2-((1R,4R)-4-(4-chlorophenyl)cyclohexyl)-3-hydroxynaphthalene-1,4-dione) 1 is described. Preliminary assessment highlighted multiple materials of concern which were largely discharged either through returning a negative bacterial mutagenicity assay or through confidence that the impurity would be purged during the downstream processing from when it was first introduced. Additional genotoxicity testing highlighted two materials of concern where initial assessment suggested that testing for these impurities at trace levels within the drug substance would be required. Following a thorough review of process purging detail, spiking and purging experimentation, and an understanding of the process parameters to which they were exposed an ICH M7 Option 4 approach could be justified for their control. The development of two 1H NMR spectroscopy methods for measurement of these impurities is also described as well as a proposed summary table for describing the underlying rationale for ICH M7 control rationales to regulators. This manuscript demonstrates that process purging of potential mutagenic impurities can be realised even when they are introduced in the later stages of a process and highlights the importance of scientific understanding rather than relying on a stage-counting approach.

Making reliable negative predictions of human skin sensitisation using an in silico fragmentation approach.

A previously published fragmentation method for making reliable negative in silico predictions has been applied to the problem of predicting skin sensitisation in humans, making use of a dataset of over 2750 chemicals with publicly available skin sensitisation data from 18 in vivo assays. An assay hierarchy was designed to enable the classification of chemicals within this dataset as either sensitisers or non-sensitisers where data from more than one in vivo test was available. The negative prediction approach was validated internally, using a 5-fold cross-validation, and externally, against a proprietary dataset of approximately 1000 chemicals with in vivo reference data shared by members of the pharmaceutical, nutritional, and personal care industries. The negative predictivity for this proprietary dataset was high in all cases (>75%), and the model was also able to identify structural features that resulted in a lower accuracy or a higher uncertainty in the negative prediction, termed misclassified and unclassified features respectively. These features could serve as an aid for further expert assessment of the negative in silico prediction.

A quantitative in silico model for predicting skin sensitization using a nearest neighbours approach within expert-derived structure-activity alert spaces.

Dermal contact with chemicals may lead to an inflammatory reaction known as allergic contact dermatitis. Consequently, it is important to assess new and existing chemicals for their skin sensitizing potential and to mitigate exposure accordingly. There is an urgent need to develop quantitative non-animal methods to better predict the potency of potential sensitizers, driven largely by European Union (EU) Regulation 1223/2009, which forbids the use of animal tests for cosmetic ingredients sold in the EU. A Nearest Neighbours in silico model was developed using an in-house dataset of 1096 murine local lymph node (LLNA) studies. The EC3 value (the effective concentration of the test substance producing a threefold increase in the stimulation index compared to controls) of a given chemical was predicted using the weighted average of EC3 values of up to 10 most similar compounds within the same mechanistic space (as defined by activating the same Derek skin sensitization alert). The model was validated using previously unseen internal (n = 45) and external (n = 103) data and accuracy of predictions assessed using a threefold error, fivefold error, European Centre for Ecotoxicology and Toxicology of Chemicals (ECETOC) and Globally Harmonized System of Classification and Labelling of Chemicals (GHS) classifications. In particular, the model predicts the GHS skin sensitization category of compounds well, predicting 64% of chemicals in an external test set within the correct category. Of the remaining chemicals in the previously unseen dataset, 25% were over-predicted (GHS 1A predicted: GHS 1B experimentally) and 11% were under-predicted (GHS 1B predicted: GHS 1A experimentally). Copyright © 2017 John Wiley & Sons, Ltd.

Vortices and turbulence in trapped atomic condensates.

After more than a decade of experiments generating and studying the physics of quantized vortices in atomic gas Bose-Einstein condensates, research is beginning to focus on the roles of vortices in quantum turbulence, as well as other measures of quantum turbulence in atomic condensates. Such research directions have the potential to uncover new insights into quantum turbulence, vortices, and superfluidity and also explore the similarities and differences between quantum and classical turbulence in entirely new settings. Here we present a critical assessment of theoretical and experimental studies in this emerging field of quantum turbulence in atomic condensates.

How can we make plants grow faster? A source-sink perspective on growth rate.

Growth is a major component of fitness in all organisms, an important mediator of competitive interactions in plant communities, and a central determinant of yield in crops. Understanding what limits plant growth is therefore of fundamental importance to plant evolution, ecology, and crop science, but each discipline views the process from a different perspective. This review highlights the importance of source-sink interactions as determinants of growth. The evidence for source- and sink-limitation of growth, and the ways in which regulatory molecular feedback systems act to maintain an appropriate source:sink balance, are first discussed. Evidence clearly shows that future increases in crop productivity depend crucially on a quantitative understanding of the extent to which sources or sinks limit growth, and how this changes during development. To identify bottlenecks limiting growth and yield, a holistic view of growth is required at the whole-plant scale, incorporating mechanistic interactions between physiology, resource allocation, and plant development. Such a holistic perspective on source-sink interactions will allow the development of a more integrated, whole-system level understanding of growth, with benefits across multiple disciplines.

Extending (Q)SARs to incorporate proprietary knowledge for regulatory purposes: A case study using aromatic amine mutagenicity.

Statistical-based and expert rule-based models built using public domain mutagenicity knowledge and data are routinely used for computational (Q)SAR assessments of pharmaceutical impurities in line with the approach recommended in the ICH M7 guideline. Knowledge from proprietary corporate mutagenicity databases could be used to increase the predictive performance for selected chemical classes as well as expand the applicability domain of these (Q)SAR models. This paper outlines a mechanism for sharing knowledge without the release of proprietary data. Primary aromatic amine mutagenicity was selected as a case study because this chemical class is often encountered in pharmaceutical impurity analysis and mutagenicity of aromatic amines is currently difficult to predict. As part of this analysis, a series of aromatic amine substructures were defined and the number of mutagenic and non-mutagenic examples for each chemical substructure calculated across a series of public and proprietary mutagenicity databases. This information was pooled across all sources to identify structural classes that activate or deactivate aromatic amine mutagenicity. This structure activity knowledge, in combination with newly released primary aromatic amine data, was incorporated into Leadscope's expert rule-based and statistical-based (Q)SAR models where increased predictive performance was demonstrated.

Principles and procedures for implementation of ICH M7 recommended (Q)SAR analyses.

The ICH M7 guideline describes a consistent approach to identify, categorize, and control DNA reactive, mutagenic, impurities in pharmaceutical products to limit the potential carcinogenic risk related to such impurities. This paper outlines a series of principles and procedures to consider when generating (Q)SAR assessments aligned with the ICH M7 guideline to be included in a regulatory submission. In the absence of adequate experimental data, the results from two complementary (Q)SAR methodologies may be combined to support an initial hazard classification. This may be followed by an assessment of additional information that serves as the basis for an expert review to support or refute the predictions. This paper elucidates scenarios where additional expert knowledge may be beneficial, what such an expert review may contain, and how the results and accompanying considerations may be documented. Furthermore, the use of these principles and procedures to yield a consistent and robust (Q)SAR-based argument to support impurity qualification for regulatory purposes is described in this manuscript.

A randomized controlled trial of a correspondence-based intervention for carers of relatives with psychosis.

BACKGROUND: Family members play a crucial role in supporting the recovery of loved ones with psychosis. The journey of recovery is not only traversed by the person experiencing the mental illness but also by their family. Interventions to support these families have traditionally either focused on psychoeducation or addressed problematic interactions or expressed emotion. Family programmes have far less frequently emphasized supporting family members' adjustment to the challenges posed by their relative's disorder or their recovery from associated distress. The study compared a control condition that received only a psychoeducational booklet (Information) and a condition also receiving a correspondence-based interactive recovery-oriented intervention (Connections). The Connections group was expected to show greater improvements in recovery knowledge, well-being, experiences of caregiving, hopefulness and distress. METHOD: A randomized controlled trial was conducted to evaluate the effectiveness of two correspondence-based family interventions delivered to 81 carers of relatives with psychosis. RESULTS: Intent-to-treat analyses showed no differential outcomes between conditions, but an analysis of participants who substantially completed their allocated treatment showed that carers receiving Connections had significantly more improvements in well-being, positive experiences of caregiving and distress. CONCLUSIONS: Correspondence interventions that support carer's recovery may result in more positive mental health for those who complete key elements of the programme compared with information alone. However, many carers do not complete a correspondence programme and this may limit its impact.

Antiretroviral interventions for preventing breast milk transmission of HIV.

BACKGROUND: An estimated 260,000 children under the age of 15 years acquired HIV infection in 2012. As much as 42% of mother-to-child transmission is related to breastfeeding. Antiretroviral prophylaxis for mothers or infants has the potential to prevent mother-to-child transmission of HIV through breast milk. OBJECTIVES: To determine which antiretroviral prophylactic regimens are efficacious and safe for reducing mother-to-child transmission of HIV through breastfeeding and thereby avert child morbidity and mortality. SEARCH METHODS: Using Cochrane Collaboration search methods in conjunction with appropriate search terms, we identified relevant studies from January 1, 1994 to January 14, 2014 by searching databases including Cochrane CENTRAL, EMBASE and PubMed, LILACS, and Web of Science/Web of Social Science. SELECTION CRITERIA: Randomized controlled trials in which HIV-infected mothers breastfed their infants, and in which the mothers used antiretroviral prophylaxis while breastfeeding their children or their children received antiretroviral prophylaxis for at least four weeks while breastfeeding, were included. DATA COLLECTION AND ANALYSIS: Abstracts of all trials identified were examined independently by two authors. We identified 15,922 references and examined 81 in detail. Data were abstracted independently using a standardized form. MAIN RESULTS: Seven RCTs were included in the review.One trial compared triple antiretroviral prophylaxis during pregnancy and breastfeeding with short antiretroviral prophylaxis to given to the mother to prevent mother-to-child transmission of HIV. At 12 months, the risks of HIV transmission, and of HIV transmission or death, were lower, but there was no difference in infant mortality alone in the triple arm versus the short arm. Using the GRADE methodology, evidence quality for outcomes in this trial was generally low to moderate.One trial compared six months of breastfeeding using zidovudine, lamivudine, and lopinavir/ritonavir versus zidovudine, lamivudine, and abacavir from 26-34 weeks gestation. At six months, there was no difference in risk of infant HIV infection, infant death, or infant HIV infection or death between the two groups. Evidence quality for outcomes in this trial was generally very low to low.One trial of single dose nevirapine versus six weeks of infant zidovudine found the risk of HIV infection at 12 weeks to be greater in the zidovudine arm than in the single dose nevirapine arm. Evidence quality for outcomes in this trial was generally very low.One multi-country trial compared single dose nevirapine and six weeks of infant nevirapine. After 12 months, infants in the extended nevirapine group had a lower risk of infant mortality compared with the control. There was no difference in the risk of HIV infection or death or in HIV transmission alone in the extended nevirapine group compared with the control. Evidence quality for outcomes in this trial was generally low to moderate.One trial compared single dose nevirapine plus one week zidovudine; the control regimen plus nevirapine up to 14 weeks; or the control regimen with dual prophylaxis up to 14 weeks. At 24 months, the extended nevirapine regimen group had a lower risk of HIV transmission and of HIV transmission or death vs. the control. There was no difference in infant mortality alone. Compared with controls, the dual prophylaxis group had a lower risk of HIV transmission and of HIV transmission or death, but no difference in infant mortality alone. There was no difference in these outcomes between the two intervention arms. Evidence quality for outcomes in this trial was generally moderate to high.One trial compared six weeks of nevirapine with six months of nevirapine. Among infants of mothers not using highly active antiretroviral therapy, there was no difference in risk of HIV infection among the six month nevirapine group versus the six week nevirapine group. Evidence quality for outcomes in this trial was generally low to moderate.One trial compared a maternal triple-drug antiretroviral regimen, infant nevirapine, or neither intervention. Infants in the maternal prophylaxis arm were at lower risk for HIV, and HIV infection or death when compared with the control group. There was no difference in the risk of infant mortality alone. Infants with extended prophylaxis had a lower risk of HIV infection and of HIV infection or death versus the control group infants. There was no difference in the risk of infant mortality alone in the extended infant nevirapine group versus the control. There was no difference in HIV infection, infant mortality, and HIV infection or death between the maternal and extended infant prophylaxis groups. Evidence quality for outcomes in this trial was generally low to moderate. AUTHORS' CONCLUSIONS: Antiretroviral prophylaxis, whether used by the HIV-infected mother or the HIV-exposed infant while breastfeeding, is efficacious in preventing mother-to-child transmission of HIV. Further research is needed regarding maternal resistance and response to subsequent antiretroviral therapy after maternal prophylaxis. An ongoing trial (IMPAACT 1077BF) compares the efficacy and safety of maternal triple antiretroviral prophylaxis versus daily infant nevirapine for prevention of mother-to-child transmission through breastfeeding.