Efficient Synthesis of Immunomodulatory Drug Analogues Enables Exploration of Structure-Degradation Relationships

The immunomodulatory drugs (IMiDs) thalidomide, pomalidomide, and lenalidomide have been approved for the treatment of multiple myeloma for many years. Recently, their use as E3 ligase recruiting elements for small-molecule-induced protein degradation has led to a resurgence in interest in IMiD synthesis and functionalization. Traditional IMiD synthesis follows a stepwise route with multiple purification steps. Herein we describe a novel one-pot synthesis without purification that provides rapid access to a multitude of IMiD analogues. Binding studies with the IMiD target protein cereblon (CRBN) reveals a narrow structure-activity relationship with only a few compounds showing sub-micromolar binding affinity in the range of pomalidomide and lenalidomide. However, anti-proliferative activity as well as Aiolos degradation could be identified for two IMiD analogues. This study provides useful insight into the structure-degradation relationships for molecules of this type as well as a rapid and robust method for IMiD synthesis.

α-Methyl-α-phenylsuccinimide ameliorates neurodegeneration in a C. elegans model of TDP-43 proteinopathy

The antiepileptic drug ethosuximide has recently been shown to be neuroprotective in various Caenorhabditis elegans and rodent neurodegeneration models. It is therefore a promising repurposing candidate for the treatment of multiple neurodegenerative diseases. However, high concentrations of the drug are required for its protective effects in animal models, which may impact on its translational potential and impede the identification of its molecular mechanism of action. Therefore, we set out to develop more potent neuroprotective lead compounds based on ethosuximide as a starting scaffold. Chemoinformatic approaches were used to identify compounds with structural similarity to ethosuximide and to prioritise these based on good predicated blood-brain barrier permeability and C. elegans bioaccumulation properties. Selected compounds were initially screened for anti-convulsant activity in a C. elegans pentylenetetrazol-induced seizure assay, as a rapid primary readout of bioactivity; and then assessed for neuroprotective properties in a C. elegans TDP-43 proteinopathy model based on pan-neuronal expression of human A315T mutant TDP-43. The most potent compound screened, α-methyl-α-phenylsuccinimide (MPS), ameliorated the locomotion defects and extended the shortened lifespan of TDP-43 mutant worms. MPS also directly protected against neurodegeneration by reducing the number of neuronal breaks and cell body losses in GFP-labelled GABAergic motor neurons. Importantly, optimal neuroprotection was exhibited by external application of 50 μM MPS, compared to 8 mM for ethosuximide. This greater potency of MPS was not due to bioaccumulation to higher internal levels within the worm, based on ¹H-nuclear magnetic resonance analysis. Like ethosuximide, the activity of MPS was abolished by mutation of the evolutionarily conserved FOXO transcription factor, daf-16, suggesting that both compounds act via the same neuroprotective pathway(s). In conclusion, we have revealed a novel neuroprotective activity of MPS that is >100-fold more potent than ethosuximide. This increased potency will facilitate future biochemical studies to identify the direct molecular target(s) of both compounds, as we have shown here that they share a common downstream DAF-16-dependent mechanism of action. Furthermore, MPS is the active metabolite of another approved antiepileptic drug, methsuximide. Therefore, methsuximide may have repurposing potential for treatment of TDP-43 proteinopathies and possibly other human neurodegenerative diseases.

Abstract OT1-06-01: OPTIMA: A prospective randomized trial to validate the predictive utility and cost-effectiveness of gene expression test-directed chemotherapy decisions in early breast cancer

Background: Multi-parameter gene expression assays (MPAs) are widely used to estimate individual patient residual risk in hormone-sensitive HER2-negative node-negative early breast cancer, allowing patients with low risk to safely avoid chemotherapy. Evidence for MPA use in node-positive breast cancer is limited. OPTIMA (Optimal Personalised Treatment of early breast cancer usIng Multi-parameter Analysis) aims to validate MPA's as predictors of chemotherapy sensitivity in a largely node-positive breast cancer population.

Methods: OPTIMA is a partially blinded multi-center, phase 3 randomized controlled trial with an adaptive two-stage design. The main eligibility criteria are women or men aged 40 or older with resected ER-positive, HER2-negative breast cancer and up to 9 involved axillary lymph nodes. Randomization is to standard management (chemotherapy and endocrine therapy) or to MPA-directed treatment. Those with a “high risk” tumor MPA score receive standard management whilst those at “low risk” are treated with endocrine therapy alone. The preliminary phase (OPTIMA prelim) evaluated the performance of several MPAs to select a test to be used in the main efficacy trial based on economic analysis, and assessed the feasibility and acceptability of a large UK trial. OPTIMA prelim used Oncotype DX as the primary discriminator; the main trial will use Prosigna (PAM50) with Prosigna Score ≤60 defined as “low-risk”. The co-primary outcomes are (1) Invasive Disease Free Survival (IDFS) and (2) cost-effectiveness of test-directed therapy. Secondary outcomes include IDFS in “low-risk” patients, quality of life and additional survival measures. An integrated qualitative recruitment study will identify and address challenges to recruitment and informed consent. Tumor blocks from all consenting participants will be banked allowing the performance of alternative MPA technologies to be evaluated. Recruitment of 4500 patients will permit demonstration of 3% non-inferiority of test-directed treatment, with 5% significance and 85% power, assuming 3 years follow-up and a control arm 5-year IDFS of at least 85%. The addition of patients from OPTIMA prelim will allow non-inferiority to be assessed with 2.5% significance.

Results: OPTIMA-prelim recruited 412 patients in 23 months from 35 sites with a 47% acceptance rate. The main study opened in January 2017. Early progress indicates that the recruitment target is achievable in the intended 46-month timescale through the participation of >100 sites

Conclusion: OPTIMA, as one of two large scale prospective trials validating the use of test-guided chemotherapy decisions in node-positive early breast cancer, is expected to have a global impact on breast cancer treatment. Experience from OPTIMA prelim showed that patient advocate support and close engagement with sites will aid trial success.

Funding: The project is funded in the UK by the NIHR HTA Programme (10/34/501). Views expressed are those of the authors and not those of the HTA Programme, NIHR, NHS or the DoH.

Citation Format: Stein RC, Makris A, Hughes-Davies L, Macpherson IR, Hall PS, Cameron DA, Earl HM, Pinder SE, Poole CJ, Rea DW, McIntosh S, Harmer V, Morgan A, Rooshenas L, Conefrey C, Donovan JL, Hulme C, McCabe C, Stallard N, Campbell A, Higgins H, Bartlett JMS, Marshall A, Dunn JA. OPTIMA: A prospective randomized trial to validate the predictive utility and cost-effectiveness of gene expression test-directed chemotherapy decisions in early breast cancer [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 OT1-06-01.

'What gets measured gets managed': revisiting the indicators for maternal and newborn health programmes

Background

The health of women and children are critical for global development. The Sustainable Development Goals (SDG) agenda and the Global Strategy for Women’s, Children’s, and Adolescent’s Health 2016–2030 aim to reduce maternal and newborn deaths, disability, and enhancement of well-being. However, information and data on measuring countries’ progress are limited given the variety of methodological challenges of measuring care around the time of birth, when most maternal and neonatal deaths and morbidities occur.

Main body

In 2015, the World Health Organization launched Mother and Newborn Information for Tracking Outcomes and Results (MoNITOR), a technical advisory group to WHO. MoNITOR comprises 14 independent global experts from a variety of disciplines selected in a competitive process for their technical expertise and regional representation. MoNITOR will provide technical guidance to WHO to ensure harmonized guidance, messages, and tools so that countries can collect useful data to track progress toward achieving the Sustainable Development Goals.

Short conclusion

Ultimately, MoNITOR will provide technical guidance to WHO to ensure harmonized guidance, messages, and tools so that countries can collect useful data to track progress toward achieving the Sustainable Development Goals.

Atypical Callosal Morphology in Developmental Language Disorder

Introduction

Developmental language disorder (DLD) is common, yet the neurobiology of DLD is poorly understood. A key hypothesis suggests atypical functional lateralization of language, which might be accompanied structurally by a deficit in inter-hemispheric connectivity of language-related regions. Indeed, aberrations of the corpus callosum have been associated with language deficits in children with frank neurological lesions and/or born pre-term. In contrast, studies examining the corpus callosum in children with DLD remain elusive.

Objective

We aimed to expand this largely understudied field by comparing callosal morphology between 17 children with DLD and 17 typically developing children carefully matched for sex and age.

Methods

We analyzed high-resolution structural magnetic resonance imaging data applying a well-validated computational approach, which captures the thickness of the corpus callosum with a high regional specificity at 100 equidistant points.

Results

As shown in Fig. 1, we observed a significantly thinner corpus callosum, particularly in the splenium, in children with DLD compared to typically developing controls (DLD < CTL).

Conclusions

These findings indicating pronounced aberrations in the brain's largest whiter matter tract make an important contribution to an understudied field of research and support the theory that DLD is accompanied by atypical lateralization of language function.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Development and Testing of a Cognitive Behavioral Therapy Resource for Children's Dental Anxiety

Cognitive Behavioral Therapy (CBT) is an evidence-based treatment for dental anxiety; however, access to therapy is limited. The current study aimed to develop a self-help CBT resource for reducing dental anxiety in children, and to assess the feasibility of conducting a trial to evaluate the treatment efficacy and cost-effectiveness of such an intervention. A mixed methods design was employed. Within phase 1, a qualitative "person-based" approach informed the development of the self-help CBT resource. This also employed guidelines for the development and evaluation of complex interventions. Within phase 2, children, aged between 9 and 16 y, who had elevated self-reported dental anxiety and were attending a community dental service or dental hospital, were invited to use the CBT resource. Children completed questionnaires, which assessed their dental anxiety and health-related quality of life (HRQoL) prior to and following their use of the resource. Recruitment and completion rates were recorded. Acceptability of the CBT resource was explored using interviews and focus groups with children, parents/carers and dental professionals. For this analysis, the authors adhered to the Mixed Methods Appraisal Tool criteria. There were 24 families and 25 dental professionals participating in the development and qualitative evaluation of the CBT resource for children with dental anxiety. A total of 56 children agreed to trial the CBT resource (66% response rate) and 48 of these children completed the study (86% completion rate). There was a significant reduction in dental anxiety (mean score difference = 7.7, t = 7.9, df = 45, P < 0.001, Cohen's d ES = 1.2) and an increase in HRQoL following the use of the CBT resource (mean score difference = -0.03, t = 2.14, df = 46, P < 0.05, Cohen's d ES = 0.3). The self-help approach had high levels of acceptability to stakeholders. These findings provide preliminary evidence for the effectiveness and acceptability of the resource in reducing dental anxiety in children and support the further evaluation of this approach in a randomized control trial. Knowledge Transfer Statement: This study details the development of a guided self-help Cognitive Behavioral Therapy resource for the management of dental anxiety in children and provides preliminary evidence for the feasibility and acceptability of this approach with children aged between 9 and 16 y. The results of this study will inform the design of a definitive trial to examine the treatment- and cost-effectiveness of the resource for reducing dental anxiety in children.

New links between SOD1 and metabolic dysfunction from a yeast model of amyotrophic lateral sclerosis

A number of genes have been linked to familial forms of the fatal motor neuron disease amyotrophic lateral sclerosis (ALS). Over 150 mutations within the gene encoding superoxide dismutase 1 (SOD1) have been implicated in ALS, but why such mutations lead to ALS-associated cellular dysfunction is unclear. In this study, we identify how ALS-linked SOD1 mutations lead to changes in the cellular health of the yeast Saccharomyces cerevisiae. We find that it is not the accumulation of aggregates but the loss of Sod1 protein stability that drives cellular dysfunction. The toxic effect of Sod1 instability does not correlate with a loss of mitochondrial function or increased production of reactive oxygen species, but instead prevents acidification of the vacuole, perturbs metabolic regulation and promotes senescence. Central to the toxic gain-of-function seen with the SOD1 mutants examined was an inability to regulate amino acid biosynthesis. We also report that leucine supplementation results in an improvement in motor function in a Caenorhabditiselegans model of ALS. Our data suggest that metabolic dysfunction plays an important role in Sod1-mediated toxicity in both the yeast and worm models of ALS.

Summary: In a new yeast model of ALS we have discovered for the first time that mutations in Sod1 can lead to the formation of toxic, soluble proteins that disrupt metabolic regulation.

Phosphorylation of Cysteine String Protein Triggers a Major Conformational Switch

Cysteine string protein (CSP) is a member of the DnaJ/Hsp40 chaperone family that localizes to neuronal synaptic vesicles. Impaired CSP function leads to neurodegeneration in humans and model organisms as a result of misfolding of client proteins involved in neurotransmission. Mammalian CSP is phosphorylated in vivo on Ser10, and this modulates its protein interactions and effects on neurotransmitter release. However, there are no data on the structural consequences of CSP phosphorylation to explain these functional effects. We show that Ser10 phosphorylation causes an order-to-disorder transition that disrupts CSP's extreme N-terminal α helix. This triggers the concomitant formation of a hairpin loop stabilized by ionic interactions between phosphoSer10 and the highly conserved J-domain residue, Lys58. These phosphorylation-induced effects result in significant changes to CSP conformation and surface charge distribution. The phospho-switch revealed here provides structural insight into how Ser10 phosphorylation modulates CSP function and also has potential implications for other DnaJ phosphoproteins.

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First structure of a phosphorylated DnaJ/Hsp40 protein

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Phosphorylation destabilizes CSP's N-terminal α helix

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Newly disordered, phosphorylated N-terminal loop binds to the J domain

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Phosphorylation causes significant changes to CSP conformation and surface charge

Abstract OT3-02-12: OPTIMA (optimal personalised treatment of early breast cancer usIng multi-parameter analysis), a prospective trial to validate the predictive utility and cost-effectiveness of gene expression test-directed chemotherapy decisions

Background: Multi-parameter gene expression assays (MPAs) are widely used to estimate individual patient residual risk and to guide chemotherapy use in hormone-sensitive HER2-negative node-negative early breast cancer. These uses of MPAs have not yet been prospectively validated. OPTIMA aims to validate the use of MPA testing to predict chemotherapy sensitivity in a largely node-positive breast cancer population.

Methods: OPTIMA is a partially blinded multi-center, phase 3 randomized controlled trial with an adaptive two-stage design. The preliminary phase (OPTIMA prelim) evaluated the performance of MPAs to identify a suitable test(s) to be used in the main efficacy trial and assessed the feasibility and acceptability of a large UK trial. Eligible patients are men or women aged 40 years or older who have surgically resected early stage breast cancer, which is ER-positive and HER2-negative and who have either 1-9 involved axillary lymph nodes or tumors of at least 30mm diameter. Randomization is to standard management (chemotherapy followed by endocrine therapy) or to MPA-directed treatment. Those with a tumor categorized as "high-risk" by the test will be assigned to standard management whilst those at "low-risk" will be treated with endocrine therapy alone. OPTIMA prelim used Oncotype DX as the primary discriminator; the main trial will use Prosigna (PAM50). The co-primary outcomes are (1) Invasive Disease Free Survival (IDFS) and (2) cost-effectiveness of test-directed therapy compared to standard practice. Secondary outcomes include IDFS in "low-risk" patients, distant disease free survival, breast cancer specific survival, overall survival and quality of life. An integrated qualitative recruitment study will identify and address challenges to recruitment and informed consent. Tumor blocks from all consenting participants will be banked allowing the performance of alternative MPA technologies to be evaluated. Recruitment of 4500 patients over 4 years will permit demonstration of 3% non-inferiority of test-directed treatment, with 5% significance and 85% power, assuming 3 years follow-up and a control arm 5-year IDFS of at least 85%. The addition of patients from OPTIMA prelim will allow non-inferiority to be assessed with 2.5% significance.

Results: OPTIMA-prelim recruited 412 patients in 23 months from 35 sites. It confirmed the acceptability of randomization to patients with a 47% acceptance rate, and to clinicians and hence the feasibility of a large prospective trial of test-directed treatment running in 100-plus UK sites. It showed that investment into research on test-directed therapy, especially with Prosigna, should be of substantial value to the NHS.

Conclusion: OPTIMA, as one of two large scale prospective trials validating the use of test-guided chemotherapy in node-positive hormone-sensitive early breast cancer will have a global impact on patient treatment. Recruitment into the main efficacy trial will commence in October 2015.

Funding: Project funded by the UK NIHR HTA Programme (10/34/501). Views expressed are those of the authors and not those of the HTA Programme, NIHR, NHS or the DoH.

Citation Format: Stein RC, Marshall A, Hall PS, Bartlett JMS, Rooshenas L, Campbell A, Cameron DA, Rea D, Macpherson I, Earl HM, Poole CJ, Francis A, Morgan A, Harmer V, Pinder SE, Stallard N, Donovan J, Hulme C, McCabe C, Hughes-Davies L, Makris A, Dunn JA. OPTIMA (optimal personalised treatment of early breast cancer usIng multi-parameter analysis), a prospective trial to validate the predictive utility and cost-effectiveness of gene expression test-directed chemotherapy decisions. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT3-02-12.