Translatability scoring in prospective and retrospective COVID drug development cases.

BACKGROUND: The ongoing pandemic of severe acute respiratory syndrome coronavirus 2 has led to an enormous surge of clinical research. So far, the speed and success rate of related drug development projects, especially of vaccines, is unprecedented. For the first time, this situation allowed for the opportunistic evaluation of a translatability score, originally proposed in 2009, in a prospective manner. METHODS: Several vaccines and treatments under development in clinical phase III trials were selected for translational scoring with the translatability score. Six prospective and six retrospective case studies were performed. The scores had to be determined for a fictive date before any results of the phase III trial were reported in any media. Spearman correlation analysis and a Kruskal Wallis test were performed for statistical evaluation. RESULTS: A significant correlation between the translatability scores and the clinical outcomes in translation was found, as judged on the basis of positive/intermediate/negative endpoint studies or market approval. The Spearman correlation analysis of all cases (r = 0.91, p < 0.001), the prospective cases alone (r = 0.93, p = 0.008), and the retrospective cases alone (r = 0.93, p = 0.008) showed a strong correlation between the score and outcome; R2 demonstrated a score-derived determination of outcomes by 86%. CONCLUSIONS: The score detects strengths and weaknesses of a given project, resulting in the opportunity of selective amelioration of a project, as well as prospective portfolio risk balancing. Its substantial predictive value that has been demonstrated here for the first time could be of particular interest for biomedical industry (pharmaceutical and device manufacturers), funding agencies, venture capitalists, and researchers in the area. Future evaluations will have to address the generalizability of results obtained in an exceptional pandemic situation, and the potential adaptations of weighing factors/items to particular therapeutic areas.

Many or too many progesterone membrane receptors? Clinical implications.

Several receptors for nongenomically initiated actions of progesterone (P4) exist, namely membrane-associated P4 receptors (MAPRs), membrane progestin receptors (mPRs), receptors for neurosteroids [GABAA receptor (GABAAR), NMDA receptor, sigma-1 and -2 receptors (S1R/S2R)], the classical genomic P4 receptor (PGR), and α/ß hydrolase domain-containing protein 2 (ABHD2). Two drugs related to this field have been approved: brexanolone (Zulresso™) for the treatment of postpartum depression, and ganaxolone (Ztalmy™) for the treatment of CDKL5 deficiency disorder. Both are derivatives of P4 and target the GABAAR. Several other indications are in clinical testing. CT1812 (Elayta™) is also being tested for the treatment of Alzheimer's disease (AD) in Phase 2 clinical trials, targeting the P4 receptor membrane component 1 (PGRMC1)/S2R complex. In this Review, we highlight emerging knowledge on the mechanisms of nongenomically initiated actions of P4 and its derivatives.

Translatability score revisited: differentiation for distinct disease areas.

BACKGROUND: Translational science supports successful transition of early biomedical research into human applications. In 2009 a translatability score to assess risk and identify strengths and weaknesses of a given project has been designed and successfully tested in case studies. The score elements, in particular the contributing weight factors, are heterogeneous for different disease areas; therefore, the score was individualized for six areas (cardiovascular, oncology, psychiatric, anti-viral, anti-bacterial/fungal and monogenetic diseases). RESULTS: FDA reviews and related literature were used for modifications of the score with emphasis on biomarkers, personalized medicine and animal models. 113 new medical entities approved by FDA from 2012 through 2016 were evaluated and metrics obtained for companion diagnostics and animal models as starting points for author-based individualization of the score. Most drugs approved in this period were related to oncology (46%), while the approvals were lowest for psychiatrics (4%). The evaluation of the FDA package inserts revealed that companion diagnostics play an important role in every field except psychiatrics. Further the analysis of the FDA reviews showed the weakness of animal models in psychiatrics and anti-virals, while useful animal models were present for all other fields. Consequently the scoring system was adapted to the different fields, resulting in increased weights for animal models, biomarker and personalized medicine in oncology. For psychiatrics the weights for animal models, biomarker and personalized medicine were decreased, while the weight for model compounds, clinical trials and surrogate or endpoint strategy were increased. For anti-viral drugs weights for in vitro data and personalized medicine were increased, while the weight for animal models was decreased. Further, for anti-bacterial/fungal drugs weights for animal models and personalized medicine were increased. Weights were increased for genetics and personalized medicine and decreased for model compounds for monogenetic orphans. CONCLUSIONS: Adaptation of the score to different disease areas should help to support a structured and diverse approach to translation and encourage researchers in the private or public sectors to further customize the score.

PGRMC2, a yet uncharacterized protein with potential as tumor suppressor, migration inhibitor, and regulator of cytochrome P450 enzyme activity.

PGRMC2 (progesterone receptor membrane component 2) is highly homologous if compared with PGRMC1, a cytochrome-related protein, which is induced in several cancers and linked to cell growth in these cancers. Further it seems to be involved in progesterone signalling and cytochrome P450 binding. For PGRMC2 only sparse information is available. Recent data show that PGRMC1 and 2 share several similar characteristics, but there are also important differences in expression and function of the both proteins. Several findings point to the fact that PGRMC2 might play a role in cancer as well. The protein influences the migration rate of ovarian cancer cells and a loss of PGRMC2 might result in higher metastasis rates. In contrast to PGRMC1 it seems more likely to act as a tumor suppressor than a promoter. Altered PGRMC2 expression was further detected in the context of term and preterm labour, though the implications of this finding are currently unknown and need further examination. PGRMC2 further might play a role in gynaecologic diseases like preterm labour and endometriosis. PGRMC2 shares the cellular localisation and the ability to bind cytochrome enzymes with PGRMC1. Further the protein was shown to influence the activity of CYP3A4. In conclusion, though not much is known about PGRMC2 so far, it deserves further examination as data point to a role of PGRMC2 as tumor suppressor, migration inhibitor and regulator of cytochrome P450 proteins.

In vitro inhibition of SKOV-3 cell migration as a distinctive feature of progesterone receptor membrane component type 2 versus type 1.

Progesterone receptor membrane component type 2 (PGRMC2) is strongly homologous to PGRMC1 which is highly expressed in ovarian cancer and other cancer cells and was claimed to play an important role in chemotherapy resistance. Whereas PGRMC1 has been extensively characterized in in vitro studies, comparably little is known about PGRMC2. To determine PGRMC2's role in ovarian cancer cell proliferation and mobility PGRMC1- and 2-depleted and -overexpressing SKOV-3 cells were generated. In electric cell-substrate impedance sensing studies, PGRMC2 negatively affects SKOV-3 migration rate if overexpressed; oppositely, depletion was associated with an increased migration rate. PGRMC1 had no effect in this assay. These effects were not associated with f-actin regulation or actin cytoskeleton reorganization. Yet, these highly homologous proteins share many properties. Both PGRMC1 and 2 are localized to the endoplasmic reticulum. As PGRMC1 was reported to interact with cytochrome P450 proteins (CYP) binding of two different CYPs to PGRMC2 was tested; a stable interaction of PGRMC2 with CYP3A4 and CYP21A2 was found in human embryonic kidney cells. For both PGRMC types, cell viability assays revealed no significant differences of SKOV-3 survival in overexpressing and depleted cells. PGRMC2 also does not seem to have any influence on the apoptotic effect of cisplatin or the antiapoptotic effect of progesterone which had been reported for PGRMC1. In contrast to PGRMC1, protein levels of PGRMC2 in SKOV-3 cells are reduced by treatment with cisplatin (30-60µM). In conclusion, we show for the first time that PGRMC2 inhibits migration of SKOV-3 ovarian cancer cells in vitro.

Translatability scoring in drug development: eight case studies.

Translational medicine describes the transfer of basic in vitro and in vivo data into human applications. In the light of low rates of market approvals for new medical entities, better strategies to predict the risk of drug development should be used to increase output and reduce costs. Recently, a scoring system to assess the translatability of early drug projects has been proposed. Here eight drugs from different therapeutic areas have been subjected to a retrospective test-run in this system fictively located at the phase II-III transition. The scores gained here underline the importance of biomarker quality which is pivotal to decrease the risk of the project in all cases. This is particularly evident for gefitinib. The EGFR mutation status is a breakthrough biomarker to predict therapeutic success which made this compound clinically acceptable, and this is plausibly reflected by a considerable increase of the translatability score. For psychiatric and Alzheimer's drugs, and for a CETP-inhibitor, the lack of suitable biomarkers and animal models is reflected by a low translatability score, well correlating with the excessive translational risk in these areas. These case studies document the apparent utility of the scoring system, at least under retrospective conditions, as the scores correlate with the outcomes at the level of market approval. Prospective validation is still missing, but these case studies are encouraging.

Nongenomic actions of aldosterone and progesterone revisited.

After almost 30 years of research, the existence of nongenomic steroid actions is no longer disputed. Yet, there is still a debate on the nature of receptors involved, and answers to the inherent questions are important for translational activities. In the case of aldosterone, the existence of receptors different from the classic mineralocorticoid receptors (MR) had been postulated 25 years ago as the pharmacology of about 50% of rapid actions of aldosterone reported so far is incompatible with MR involvement (insensitivity to classic MR antagonists). Candidates proposed as alternatives to MR were protein kinase C, sodium-potassium ATPase or aberrant forms of MR, none of which supported convincing evidence to represent 'the aldosterone membrane receptor'. Early in 2011, data on GPR30 showed its involvement in rapid aldosterone action, and major pharmacological aspects of this action are compatible with the landmark deviations from MR pharmacology mentioned above. GPR30, therefore, may be a receptor candidate for nongenomic aldosterone action. Similarly, a variety of promising candidates mediating rapid progesterone action has been described, including progesterone receptor membrane component 1 (PGRMC1) which seems to be associated with tumor proliferation, and membrane progesterone receptor (mPR) originally identified in fish with potential linkage to reproductive processes. So far, no candidate was unanimously convincing. In 2010, two independent groups reported that CatSper, a calcium channel, is a strong receptor candidate for the rapid action of progesterone on sperm fertilization. With these novel receptors cloned, translational activities ultimately leading to new drugs for cardiovascular protection (in the case of aldosterone) or fertilization benefits (for progesterone) are much more promising.

Involvement of let-7/miR-98 microRNAs in the regulation of progesterone receptor membrane component 1 expression in ovarian cancer cells.

PGRMC1 (progesterone receptor membrane component 1) is part of a multi-protein complex, that is highly expressed in several cancers and is involved in chemoresistance. Although PGRMC1 plays an important role in various cancers, little is known about how PGRMC1 expression is regulated. Therefore, the present study was designed to elucidate the molecular mechanisms that influence PGRMC1 expression in ovarian cancer cells. An in silico approach revealed that the 3'-untranslated region of PGRMC1 contains one highly and one poorly conserved binding site for the microRNA let-7/miR-98 and one highly conserved binding site for miR-141/200a. Luciferase assays and real-time PCRs showed that the let-7 isoforms let-7i and miR-98 target PGRMC1 in SKOV-3 cells. In contrast, the conserved binding site for miR-200a/141 in the 3'-UTR of PGRMC1 is not functional. Stimulation of SKOV-3 cells with progesterone resulted in a decrease in PGRMC1 mRNA levels. Further, an analysis of endogenous let-7i levels in SKOV-3 cells revealed that let-7i expression increased after stimulation with progesterone. Therefore, progesterone may exert its effect on PGRMC1 expression in part by stimulation of let-7i. In conclusion, we propose that PGRMC1 expression is regulated by the miRNAs let-7/miR-98, which could become therapeutic targets, as PGRMC1, like many other targets of let-7, seems to be involved in cancer proliferation and chemotherapy resistance.

The translatability of animal models for clinical development: biomarkers and disease models.

Translational science in medicine describes the transfer of basic in vitro and in vivo research into human applications. Animal models are important tools in translational science, and several different approaches such as genetically engineered animals, xenograft models, inbred strains and disease induction models are available for many diseases. Biomarkers are defined as any measurable parameters of biological processes. This includes disease pathophysiology and the impact of interventions thereon. Biomarkers represent the most important tool of translational science in medicine. Therefore, the development of biomarkers, which are useful and accessible both in animals and in humans, represents an important focus of translational activities. Imaging, for example, is translationally ideal as the readouts in disease models and patients are the same or at least very similar. Despite several approved animal models, the majority of compounds tested successfully in animals still fail to be successfully applied to human diseases. To reduce this rate of failure, animal models better resembling the human situation are needed. A new scoring system for the assessment of translatability is discussed; it facilitates the judgement on the predictivity of results from a given animal model regarding human translation by the weighed answers to important data features. These include robust animal data in more than one species, related human data and accessibility.

Position paper: Rapid responses to steroids: current status and future prospects.

Steroids exert their actions through several pathways. The classical genomic pathway, which involves binding of steroids to receptors and subsequent modulation of gene expression, is well characterized. Besides this, rapid actions of steroids have been shown to exist. Since 30 years, research on rapid actions of steroids is an emerging field of science. Today, rapid effects of steroids are well established, and are shown to exist for every type of steroid. The classical steroid receptors have been shown to be involved in rapid actions, but there is also strong evidence that unrelated structures mediate these rapid effects. Despite increasing knowledge about the mechanisms and structures which mediate these actions, there is still no unanimous acceptance of this category. This article briefly reviews the history of the field including current controversies and challenges. It is not meant as a broad review of literature, but should increase the awareness of the endocrinology society for rapid responses to steroids. As members of the organizing committee of the VI International Meeting on Rapid Responses to Steroid Hormones 2009, we propose a research agenda focusing on the identification of new receptoral structures and the identification of mechanisms of actions at physiological steroid concentrations. Additionally, efforts for the propagation of translational studies, which should finally lead to clinical benefit in the area of rapid steroid action research, should be intensified.

Translational research on rapid steroid actions.

Translational research is a burgeoning science that shows potential to improve the transition of research from bench to bedside. This novel science explores all major aspects of preclinical and clinical issues which are relevant for the success of translational pharmaceutical or medical device/diagnostic innovations. This includes target risk assessment, biomarker evaluation and predictivity grading both for efficacy and toxicity, early human trial design adequate to guide stop/go decisions on grounds of biomarker panels, and biostatistical methods to analyze multiple readout situations and quantify risk projections. Representing a comparably novel science, rapid steroid actions have been recognized to carry potential clinical implications in various fields. Findings in this field have not yet been successfully translated into clinically relevant new medicines except for neurosteroids. A promising compound is the membrane estrogen receptor agonist STX, which may be applicable for estrogen withdrawal symptoms. Nongenomic vitamin D analogs may be useful as antiinflammatory, anticancer or diabetes preventing agents. Further the membrane thyroid receptor agonist tetrac may be useful in cancer treatment. Unfortunately lazaroids (membrane-only active glucocorticoids), which have been clinically tested as neuroprotective agents, had to be abandoned because of lacking clinical efficacy. Yet, the hierarchy of antirheumatic glucocorticoid action in regard to their clinical potency may better correlate with their membrane effects than their ability to bind to the classic glucocorticoid receptor. To improve the translational success of the rapid actions of steroids research, scientists should become familiar with major aspects of translational work and always seek for translational dimensions in their research.

Glyoxalase II does not support methylglyoxal detoxification but serves as a general trypanothione thioesterase in African trypanosomes.

Glyoxalase I and II form a ubiquitous glutathione-dependent pathway for the detoxification of reactive and mutagenic ketoaldehydes. Methylglyoxal produced as spontaneous by-product of glycolysis is probably the main physiological substrate. Consequently, African trypanosomes with their exorbitant glucose turnover were expected to have a most efficient detoxification system. Trypanosoma brucei possesses a trypanothione [bis(glutathionyl)spermidine]-dependent glyoxalase II but lacks a glyoxalase I gene. Methylglyoxal reductase as well as dehydrogenase activities are negligible. However, the concentrations of methylglyoxal and advanced glycation end products in the parasites are similar to those in different mammalian cells and the mechanism of methylglyoxal elimination remains elusive. Glyoxalase II is an abundant protein. Overexpression of the gene as well as RNA interference in bloodstream and procyclic cells did not result in a growth phenotype. Deletion of both alleles in procyclic parasites revealed that the enzyme is not essential at least under culture conditions. Recombinant glyoxalase II hydrolyzed the trypanothione-thioesters of methylglyoxal, glyoxal and 4,5-dioxovalerate, substrates of the classical glyoxalase system, with high efficiency. The absence of a glyoxalase I, however, renders these thioesters unlikely as physiological substrates. Here we show that trypanothione-thioesters can be generated from the respective coenzyme A derivative by transesterification. S-Acetyl- and S-propionyltrypanothione obtained by this spontaneous reaction proved to be excellent substrates of T. brucei glyoxalase II. This offers a function for the parasite glyoxalase II as general trypanothione thioesterase independent of ketoaldehyde detoxification.

Sequencing of hemoglobin gene 4 (dmhb4) and Southern blot analysis provide evidence of more than four members of the Daphnia magna globin family.

A genomic fragment containing the hemoglobin gene dmhb4 of Daphnia magna was cloned and its nucleotide sequence determined. Concerning induction under hypoxic conditions, dmhb4 was found to be expressed constitutively with similar mRNA quantities in D. magna bred in either normoxic or hypoxic medium. Southern blot analysis revealed at least six hemoglobin-like sequences in the genome of Daphnia magna.