VenomPred: A Machine Learning Based Platform for Molecular Toxicity Predictions.

The use of in silico toxicity prediction methods plays an important role in the selection of lead compounds and in ADMET studies since in vitro and in vivo methods are often limited by ethics, time, budget and other resources. In this context, we present our new web tool VenomPred, a user-friendly platform for evaluating the potential mutagenic, hepatotoxic, carcinogenic and estrogenic effects of small molecules. VenomPred platform employs several in-house Machine Learning (ML) models developed with datasets derived from VEGA QSAR, a software that includes a comprehensive collection of different toxicity models and has been used as a reference for building and evaluating our ML models. The results showed that our models achieved equal or better performance than those obtained with the reference models included in VEGA QSAR. In order to improve the predictive performance of our platform, we adopted a consensus approach combining the results of different ML models, which was able to predict chemical toxicity better than the single models. This improved method was thus implemented in the VenomPred platform, a freely accessible webserver that takes the SMILES (Simplified Molecular-Input Line-Entry System) strings of the compounds as input and sends the prediction results providing a probability score about their potential toxicity.

A multiscale approach for bridging the gap between potency, efficacy, and safety of small molecules directed at membrane proteins.

Membrane proteins constitute a substantial fraction of the human proteome, thus representing a vast source of therapeutic drug targets. Indeed, newly devised technologies now allow targeting "undruggable" regions of membrane proteins to modulate protein function in the cell. Despite the advances in technology, the rapid translation of basic science discoveries into potential drug candidates targeting transmembrane protein domains remains challenging. We address this issue by harmonizing single molecule-based and ensemble-based atomistic simulations of ligand-membrane interactions with patient-derived induced pluripotent stem cell (iPSC)-based experiments to gain insights into drug delivery, cellular efficacy, and safety of molecules directed at membrane proteins. In this study, we interrogated the pharmacological activation of the cardiac Ca2+ pump (Sarcoplasmic reticulum Ca2+-ATPase, SERCA2a) in human iPSC-derived cardiac cells as a proof-of-concept model. The combined computational-experimental approach serves as a platform to explain the differences in the cell-based activity of candidates with similar functional profiles, thus streamlining the identification of drug-like candidates that directly target SERCA2a activation in human cardiac cells. Systematic cell-based studies further showed that a direct SERCA2a activator does not induce cardiotoxic pro-arrhythmogenic events in human cardiac cells, demonstrating that pharmacological stimulation of SERCA2a activity is a safe therapeutic approach targeting the heart. Overall, this novel multiscale platform encompasses organ-specific drug potency, efficacy, and safety, and opens new avenues to accelerate the bench-to-patient research aimed at designing effective therapies directed at membrane protein domains.

Case Study 6: Deconvoluting Hyperbilirubinemia-Differentiating Between Hepatotoxicity and Reversible Inhibition of UGT1A1, MRP2, or OATP1B1 in Drug Development.

New molecular entities (NMEs) are evaluated using a rigorous set of in vitro and in vivo studies to assess their safety and suitability for testing in humans. Regulatory health authorities require that therapeutic and supratherapeutic doses be administered, by the intended route of administration, to two nonclinical species prior to human testing. The purpose of these studies is to identify potential target organ toxicity and to determine if the effects are reversible. Liver is a potential site for toxicity caused by orally administered NMEs due to high exposure during first pass after oral administration. A range of clinical chemistry analytes are routinely measured in both nonclinical and clinical studies to evaluate and monitor for hepatotoxicity. While bilirubin itself circulates within a wide range of concentrations in many animal species and humans, without causing adverse effects and possibly providing benefits, bilirubin is one of the few readily monitored circulating biomarkers that can provide insight into liver function. Therefore, any changes in plasma or urine bilirubin levels must be carefully evaluated. Changes in bilirubin may occur as a result of adaptive nontoxic changes or severe toxicity. Examples of adaptive nontoxic changes in liver function, which may elevate direct (conjugated) and/or indirect (unconjugated) bilirubin above baseline levels, include reversible inhibition of UGT1A1-mediated bilirubin metabolism and OATP1B1-, OATP1B3-, or MRP2-mediated transport. Alternatively, hepatocellular necrosis, hypoalbuminuria, or cholestasis may also lead to elevation of bilirubin; in some cases, these effects may be irreversible.This chapter aims to demonstrate application of enzyme kinetic principles in understanding the risk of bilirubin elevation through inhibition of multiple processes-involving both enzymes and transporters. In the sections that follow, we first provide a brief summary of bilirubin formation and disposition. Two case examples are then provided to illustrate the enzyme kinetic studies needed for risk assessment and for identifying the mechanisms of bilirubin elevation. Caveats of methods and data interpretation are discussed in these case studies. The data presented in this chapter is unpublished at the time of compilation of this book. It has been incorporated in this chapter to provide a sense of complexities in enzyme kinetics to the reader.

Safety and pharmacokinetics of milademetan, a MDM2 inhibitor, in Japanese patients with solid tumors: A phase I study.

Milademetan (DS-3032, RAIN-32) is an orally available mouse double minute 2 (MDM2) antagonist with potential antineoplastic activity owing to increase in p53 activity through interruption of the MDM2-p53 interaction. This phase I, dose-escalating study assessed the safety, tolerability, efficacy, and pharmacokinetics of milademetan in 18 Japanese patients with solid tumors who relapsed after or were refractory to standard therapy. Patients aged ≥ 20 years received oral milademetan once daily (60 mg, n = 3; 90 mg, n = 11; or 120 mg, n = 4) on days 1 to 21 in a 28-day cycle. Dose-limiting toxicities, safety, tolerability, maximum tolerated dose, pharmacokinetics, and recommended dose for phase II were determined. The most frequent treatment-emergent adverse events included nausea (72.2%), decreased appetite (61.1%), platelet count decreased (61.1%), white blood cell count decreased (50.0%), fatigue (50.0%), and anemia (50.0%). Dose-limiting toxicities (three events of platelet count decreased and one nausea) were observed in the 120-mg cohort. The plasma concentrations of milademetan increased in a dose-dependent manner. Stable disease was observed in seven out of 16 patients (43.8%). Milademetan was well tolerated and showed modest antitumor activity in Japanese patients with solid tumors. The recommended dose for phase II was considered to be 90 mg in the once-daily 21/28-day schedule. Future studies would be needed to further evaluate the potential safety, tolerability, and clinical activity of milademetan in patients with solid tumors and lymphomas. The trial was registered with Clinicaltrials.jp: JapicCTI-142693.

A Phase 1 study of RO6870810, a novel bromodomain and extra-terminal protein inhibitor, in patients with NUT carcinoma, other solid tumours, or diffuse large B-cell lymphoma.

BACKGROUND: Bromodomain and extra-terminal (BET) proteins are epigenetic readers that can drive carcinogenesis and therapy resistance. RO6870810 is a novel, small-molecule BET inhibitor. METHODS: We conducted a Phase 1 study of RO6870810 administered subcutaneously for 21 or 14 days of 28- or 21-day cycles, respectively, in patients with the nuclear protein of the testis carcinoma (NC), other solid tumours, or diffuse large B-cell lymphoma (DLBCL) with MYC deregulation. RESULTS: Fatigue (42%), decreased appetite (35%) and injection-site erythema (35%) were the most common treatment-related adverse events. Pharmacokinetic parameters demonstrated linearity over the dose range tested and support once-daily dosing. Pharmacodynamic assessments demonstrated sustained decreases in CD11b levels in peripheral blood mononuclear cells. Objective response rates were 25% (2/8), 2% (1/47) and 11% (2/19) for patients with NC, other solid tumours and DLBCL, respectively. Responding tumours had evidence of deregulated MYC expression. CONCLUSIONS: This trial establishes the safety, favourable pharmacokinetics, evidence of target engagement and preliminary single-agent activity of RO6870810. Responses in patients with NC, other solid tumours and DLBCL provide proof-of-principle for BET inhibition in MYC-driven cancers. The results support further exploration of RO6870810 as monotherapy and in combinations. CLINICAL TRIALS REGISTRATION: NCT01987362.

Pulmonary adverse events of small molecule JAK inhibitors in autoimmune disease: systematic review and meta-analysis.

OBJECTIVES: Small molecule tyrosine kinase inhibitors [smTKI, comprising mostly of Janus kinase (JAK) and to a lesser extent, spleen tyrosine kinase (SyK) inhibitors] modulate the cytokine receptor-mediated intracellular signal cascade, and are an effective treatment for autoimmune diseases and malignancies. As smTKI are novel, long-term safety is uncertain. Due to increasing use, characterization of their true adverse event profile is critical. METHODS: We performed a systematic review and meta-analysis of all published trial data on the pulmonary and serious adverse effects of smTKIs in autoimmune disease. EMBASE, MEDLINE, CENTRAL and Pneumotox databases were searched up to April 2019 for randomized controlled trials, observational studies and post marketing surveillance, comparing any smTKI with placebo or another therapy, or as monotherapy at different doses. Primary outcomes comprised of any respiratory complications including upper and lower respiratory tract infections (URTI, LRTI), influenza, pneumonia, opportunistic respiratory infections, drug-induced interstitial lung disease, pulmonary embolism and lung neoplasm. RESULTS: We identified 4667 citations for screening, and selected 319 studies for full text review. Seventy-nine studies were analysed, including 47 randomized controlled trials, 25 observational studies and seven post-marketing surveillance studies, comprising 159 652 participants. There were significantly increased risks of URTI [risk difference (RD) 0.03; 95% CI: 0.01, 0.05; P = 0.00; 36 studies, 14 724 participants], LRTI (RD 0.01; 95% CI: 0.00, 0.02; P = 0.02; 24 studies, 12 302 participants), influenza (RD 0.01; 95% CI: 0.00, 0.01; P = 0.04; 22 studies, 10 684 participants), and pneumonia (RD 0.00; 95% CI: 0.00, 0.01; P = 0.02; 33 studies, 15 511 participants). No increased risk was found for other respiratory complications, including pulmonary embolism. CONCLUSION: SmTKI increases the risk of non-opportunistic respiratory infections compared with placebo. The risk of any serious pulmonary adverse events is low.

In Silico Prediction of Hemolytic Toxicity on the Human Erythrocytes for Small Molecules by Machine-Learning and Genetic Algorithm.

Hemolytic toxicity of small molecules, as one of the important ADMET end points, can cause the lysis of erythrocytes membrane and leaking of hemoglobin into the blood plasma, which leads to various side effects. Thus, it is very crucial to assess the hemolytic potential of small molecules during the early stage of drug development process. However, so far there is no computational model to predict the human hemolytic toxicity of small molecules. To this end, we manually curate the hemolytic toxicity data set for the small molecules experimentally evaluated on the human erythrocytes, develop the first machine-learning (ML) based models to predict the human hemolytic toxicity of small molecules, harness the genetic algorithm (GA) and ML based model to optimize human hemolytic toxicity based on the molecular fingerprint to derive "optimal virtual fingerprints (OVFs)" with the desired hemolytic/nonhemolytic property, and finally implement a free software for the users to predict/optimize the human hemolytic toxicity with ML and GA in the automatic manner.

Emerging angiogenesis inhibitors for non-small cell lung cancer.

Introduction: Angiogenesis represents a complex process crucial during embryo development, wound healing, and collateral formation for improved organ perfusion. Numerous stimulatory and inhibitory pathways through their balance regulate angiogenesis and vascular homeostasis. Targeting the pathways implicated in the regulation of angiogenesis and neo-angiogenesis plays an important role in cancer research, treatment, and patients' outcome. Antiangiogenic strategies, including monoclonal antibodies binding vascular endothelial growth factor (VEGF) or the corresponding receptor and small molecules which inhibit the function of different angio-related tyrosine kinase, produced interesting results in cancer treatments including non-small-cell lung cancer (NSCLC). Areas covered: The current state-of-the-art of anti-angiogenesis treatment in the management of NSCLC patients is reviewed and discussed. A structured search of bibliographic databases for peer-reviewed research literature and of main meetings using a focused review question was undertaken in order to discuss about emerging angiogenesis inhibitors in NSCLC. Expert opinion: Targeting angiogenesis remains an important therapeutic strategy in the management of NSCLC. Moreover, VEGF has been recognized having also an immunosuppressive action leading to investigate the potential activity of angiogenic inhibitors in restoring the antitumor immunity by targeting VEGF/VEGF-Receptor. Furthermore, new anti-angiogenic drugs for which there is also the availability of predictive biomarkers are welcome.

Surufatinib in Advanced Well-Differentiated Neuroendocrine Tumors: A Multicenter, Single-Arm, Open-Label, Phase Ib/II Trial.

PURPOSE: No antiangiogenic treatment is yet approved for extrapancreatic neuroendocrine tumors (NET). Surufatinib (HMPL-012, previously named sulfatinib) is a small-molecule inhibitor targeting vascular endothelial growth factor receptors, fibroblast growth factor receptor 1 and colony-stimulating factor 1 receptor. We conducted a single-arm phase Ib/II study of surufatinib in advanced NETs. PATIENTS AND METHODS: Patients with histologically well-differentiated, low or intermittent grade, inoperable or metastatic NETs were enrolled into a pancreatic or extrapancreatic NET cohort. Patients were treated with surufatinib 300 mg orally, once daily. The primary endpoints were safety and objective response rate (ORR) according to Response Evaluation Criteria in Solid Tumors (version 1.1). RESULTS: Of the 81 patients enrolled, 42 had pancreatic NETs and 39 had extrapancreatic NETs. Most patients had radiologic progression within 1 year prior to enrollment (32 patients in each cohort). In the pancreatic and extrapancreatic NET cohorts, ORRs were 19% [95% confidence intervals (CI), 9-34] and 15% (95% CI, 6-31), disease control rates were 91% (95% CI, 77-97) and 92% (95% CI, 79-98), and median progression-free survival was 21.2 months (95% CI, 15.9-24.8) and 13.4 months (95% CI, 7.6-19.3), respectively. The most common grade ≥3 treatment-related adverse events were hypertension (33%), proteinuria (12%), hyperuricemia (10%), hypertriglyceridemia, and diarrhea (6% for each), and increased alanine aminotransferase (5%). CONCLUSIONS: Surufatinib showed encouraging antitumor activity and manageable toxicities in patients with advanced NETs. Two ongoing phase III studies, validating the efficacy of surufatinib in patients with NETs, will contribute to the clinical evidence.

The integration of pharmacophore-based 3D QSAR modeling and virtual screening in safety profiling: A case study to identify antagonistic activities against adenosine receptor, A2A, using 1,897 known drugs.

Safety pharmacology screening against a wide range of unintended vital targets using in vitro assays is crucial to understand off-target interactions with drug candidates. With the increasing demand for in vitro assays, ligand- and structure-based virtual screening approaches have been evaluated for potential utilization in safety profiling. Although ligand based approaches have been actively applied in retrospective analysis or prospectively within well-defined chemical space during the early discovery stage (i.e., HTS screening and lead optimization), virtual screening is rarely implemented in later stage of drug discovery (i.e., safety). Here we present a case study to evaluate ligand-based 3D QSAR models built based on in vitro antagonistic activity data against adenosine receptor 2A (A2A). The resulting models, obtained from 268 chemically diverse compounds, were used to test a set of 1,897 chemically distinct drugs, simulating the real-world challenge of safety screening when presented with novel chemistry and a limited training set. Due to the unique requirements of safety screening versus discovery screening, the limitations of 3D QSAR methods (i.e., chemotypes, dependence on large training set, and prone to false positives) are less critical than early discovery screen. We demonstrated that 3D QSAR modeling can be effectively applied in safety assessment prior to in vitro assays, even with chemotypes that are drastically different from training compounds. It is also worth noting that our model is able to adequately make the mechanistic distinction between agonists and antagonists, which is important to inform subsequent in vivo studies. Overall, we present an in-depth analysis of the appropriate utilization and interpretation of pharmacophore-based 3D QSAR models for safety screening.

Skin adverse events in recently approved targeted therapies in solid malignancies.

Targeted anticancer therapies are an important weapon in the fight against cancer. Targeted therapies interfere with specific molecules necessary for tumor growth and cancer progression. They are divided mainly to either monoclonal antibodies or small molecules inhibitors. Their primary objective is to target directly and precisely the cancer cells leading to a minimal side-effects profile. The dermatologic adverse reactions of these targeted therapies is different from those seen with classical cytotoxic chemotherapy. Rashes, xerosis, hand-foot-skin reaction and mucositis are the most frequent side effects. In this paper, we aim to present a comprehensive review of the dermatologic side effects of targeted therapies including, specific side effects related to recently, approved targeted therapies.

Oral small molecules for the treatment of atopic dermatitis: a systematic review.

Introduction: Atopic dermatitis (AD) is a chronic, inflammatory skin disease. Conventional treatments include topical emollients, corticosteroids, calcineurin inhibitors, phototherapy, and systemic immunomodulatory agents, however, these medications have limitations in the treatment of moderate to severe AD. Current literature demonstrates that oral small molecules may be an effective modality to treat AD. Method: Using PubMed/MEDLINE, Embase, Cochrane Skin databases and clinicaltrials.gov a search with terms 'atopic dermatitis or atopic eczema' and 'name of the oral small molecule' was conducted resulting in 1197 articles. Inclusion criteria were studies involving human subjects treated with oral small molecule medication for AD and written in English. Randomized clinical trials, open-label prospective trials, and case reports/series were reviewed. Results: Seven articles, with a total of 250 patients, were included for review. Oral small molecules studied include: apremilast, baricitinib, JNJ-39758979, and tofacitinib. Small molecules demonstrate improvement in AD disease scores, patient-reported outcomes, and quality of life. Conclusion: Preliminary results demonstrate that oral small molecules are an effective treatment option in AD with minimal side effects. Additional randomized studies with larger sample sizes are needed to determine the efficacy and long-term side effects of these novel therapies.

Evaluation of the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of a Single Intravenous Dose of Miridesap in Healthy Japanese Subjects.

This phase 1 study characterized the safety, tolerability, pharmacokinetics, and pharmacodynamics of miridesap (GSK2315698) following an intravenous (IV) infusion in healthy Japanese men. Subjects in Cohort 1 received 1-hour IV infusions of 10, 20, and 40 mg of miridesap or placebo, and subjects in Cohort 2 received a 15-hour IV infusion of 20 mg/h of miridesap or placebo. No treatment-related adverse events were reported. No new safety signals were identified for either vital signs or clinical laboratory parameters. A dose-dependent increase was observed in miridesap exposure (area under the concentration-time curve and maximum observed drug concentration) in the 10 to 40 mg/h dose range after a 1-hour IV infusion of miridesap. Rapid depletion of circulating serum amyloid P component was observed after the initiation of miridesap infusion. Serum amyloid P component concentrations fell in a dose-dependent manner following administration of miridesap.

WINDOW consortium: A path towards increased therapy efficacy against glioblastoma.

Glioblastoma is the most common and malignant form of brain cancer, for which the standard treatment is maximal surgical resection, radiotherapy and chemotherapy. Despite these interventions, mean overall survival remains less than 15 months, during which extensive tumor infiltration throughout the brain occurs. The resulting metastasized cells in the brain are characterized by chemotherapy resistance and extensive intratumoral heterogeneity. An orthogonal approach attacking both intracellular resistance mechanisms as well as intercellular heterogeneity is necessary to halt tumor progression. For this reason, we established the WINDOW Consortium (Window for Improvement for Newly Diagnosed patients by Overcoming disease Worsening), in which we are establishing a strategy for rational selection and development of effective therapies against glioblastoma. Here, we overview the many challenges posed in treating glioblastoma, including selection of drug combinations that prevent therapy resistance, the need for drugs that have improved blood brain barrier penetration and strategies to counter heterogeneous cell populations within patients. Together, this forms the backbone of our strategy to attack glioblastoma.

Small-Molecule Immune Checkpoint Inhibitors Targeting PD-1/PD-L1 and Other Emerging Checkpoint Pathways.

Advances in harnessing the immune system for cancer treatment have been spectacular in recent years as witnessed by the approval of a number of antibodies targeting the PD-1/PD-L1 immune checkpoint pathway spanning an expanding list of indications. However, it is well recognized that while these antibodies show impressive clinical activity, they suffer from shortcomings including the failure to show response in a majority of patients, their need to be administered by intravenous injection, and immune-related adverse events due to the breaking of immune self-tolerance. Small-molecule-based therapeutic approaches offer the potential to address the shortcomings of these antibody-based checkpoint inhibitors. In the first part of this review, we discuss the rationale for small-molecule-based checkpoint therapy followed by efforts on the discovery of small-molecule-based approaches targeting the PD-1/PD-L1 axis and other immune checkpoint pathways. In the latter part of the article, we describe small-molecule inhibitors simultaneously targeting two non-redundant checkpoint inhibitor pathways as an approach to improve the response rate. A brief review of the progress of an oral small-molecule checkpoint inhibitor currently in clinical development is presented at the end.

Models and Approaches Describing the Metabolism, Transport, and Toxicity of Drugs Administered by the Ocular Route.

The eye is a complex organ with a series of anatomic barriers that provide protection from physical and chemical injury while maintaining homeostasis and function. The physiology of the eye is multifaceted, with dynamic flows and clearance mechanisms. This review highlights that in vitro ocular transport and metabolism models are confined by the availability of clinically relevant absorption, distribution, metabolism, and excretion (ADME) data. In vitro ocular transport models used for pharmacology and toxicity poorly predict ocular exposure. Although ocular cell lines cannot replicate in vivo conditions, these models can help rank-order new chemical entities in discovery. Historic ocular metabolism of small molecules was assumed to be inconsequential or assessed using authentic standards. While various in vitro models have been cited, no single system is perfect, and many must be used in combination. Several studies document the use of laboratory animals for the prediction of ocular pharmacokinetics in humans. This review focuses on the use of human-relevant and human-derived models which can be utilized in discovery and development to understand ocular disposition of new chemical entities. The benefits and caveats of each model are discussed. Furthermore, ADME case studies are summarized retrospectively and capture the ADME data collected for health authorities in the absence of definitive guidelines. Finally, we discuss the novel technologies and a hypothesis-driven ocular drug classification system to provide a holistic perspective on the ADME properties of drugs administered by the ocular route.

Biosimilars for Immune-Mediated Chronic Diseases in Primary Care: What a Practicing Physician Needs to Know.

The introduction of biologics has revolutionized the treatment of immune-mediated diseases, but high cost and limited patient access remain hurdles, and some physicians are concerned that biosimilars are not similar enough. The purpose of this narrative review is to describe biosimilar safety, efficacy, nomenclature, extrapolation and interchangeability. In the United States, the Biologics Price Competition and Innovation Act created an abbreviated pathway for licensing of a biologic that is biosimilar to another licensed product (i.e., the reference product). This approval pathway differs from that of generic small-molecule drugs because biologics are too complex to be perfectly duplicated, and follows a process designed to demonstrate that any differences between the biosimilar and its reference product have no significant impact on safety and efficacy. The US approval process requires extensive analytical assessments, animal studies and clinical trials, assuring that biosimilar products provide clinical results similar to those of the reference product.

Systems pharmacological analysis of mitochondrial cardiotoxicity induced by selected tyrosine kinase inhibitors.

Tyrosine kinase inhibitors (TKIs) are targeted therapies rapidly becoming favored over conventional cytotoxic chemotherapeutics. Our study investigates two FDA approved TKIs, DASATINIB; indicated for IMATINIB-refractory chronic myeloid leukemia, and SORAFENIB; indicated for hepatocellular carcinoma and advanced renal cell carcinoma. Limited but crucial evidence suggests that these agents can have cardiotoxic side effects ranging from hypertension to heart failure. A greater understanding of the underlying mechanisms of this cardiotoxicity are needed as concerns grow and the capacity to anticipate them is lacking. The objective of this study was to explore the mitochondrial-mediated cardiotoxic mechanisms of the two selected TKIs. This was achieved experimentally using immortalized human cardiomyocytes, AC16 cells, to investigate dose- and time-dependent cell killing, along with measurements of temporal changes in key signaling proteins involved in the intrinsic apoptotic and autophagy pathways upon exposure to these agents. Quantitative systems pharmacology (QSP) models were developed to capture the toxicological response in AC16 cells using protein dynamic data. The developed QSP models captured well all the various trends in protein signaling and cellular responses with good precision on the parameter estimates, and were successfully qualified using external data sets. An interplay between the apoptotic and autophagic pathways was identified to play a major role in determining toxicity associated with the investigated TKIs. The established modeling platform showed utility in elucidating the mechanisms of cardiotoxicity of SORAFENIB and DASATINIB. It may be useful for other small molecule targeted therapies demonstrating cardiac toxicities, and may aid in informing alternate dosing strategies to alleviate cardiotoxicity associated with these therapies.

Assessment of Safety, Tolerability, Pharmacokinetics, and Pharmacological Effect of Orally Administered CORT125134: An Adaptive, Double-Blind, Randomized, Placebo-Controlled Phase 1 Clinical Study.

CORT125134 is an orally active, high-affinity, selective antagonist of the glucocorticoid receptor that is being developed for indications that may benefit from the modulation of cortisol activity. This first-in-human study was conducted to evaluate the dose-related safety, tolerability, pharmacokinetics and pharmacological effects of CORT125134 and its active metabolite CORT125201. Eighty-one healthy male or female subjects received a single dose of 5 to 500 mg CORT125134 or matching placebo across 9 cohorts; 1 cohort received 150 mg CORT125134 after a high-fat breakfast; and 46 subjects received 50 to 500 mg CORT125134 or matching placebo once daily for up to 14 days across 4 cohorts. CORT125134 was well tolerated at doses up to 250 mg per day for 14 days. CORT125134 was absorbed rapidly and eliminated with a mean half-life ranging from 11 to 19 hours. Steady state was achieved by day 7. Exposure increased in a greater than proportional manner, particularly at lower doses. Exposure to CORT125201 at steady state was less than 5% that of parent CORT125134. Evidence for the desired pharmacological effect (glucocorticoid receptor antagonism) was demonstrated by the ability of CORT125134 to prevent several effects of the glucocorticoid receptor agonist prednisone.

A novel orally available small molecule that inhibits hepatitis B virus expression.

BACKGROUND & AIMS: The hallmarks of chronic HBV infection are a high viral load (HBV DNA) and even higher levels (>100-fold in excess of virions) of non-infectious membranous particles containing the tolerogenic viral S antigen (HBsAg). Currently, standard treatment effectively reduces viremia but only rarely results in a functional cure (defined as sustained HBsAg loss). There is an urgent need to identify novel therapies that reduce HBsAg levels and restore virus-specific immune responsiveness in patients. We report the discovery of a novel, potent and orally bioavailable small molecule inhibitor of HBV gene expression (RG7834). METHODS: RG7834 antiviral characteristics and selectivity against HBV were evaluated in HBV natural infection assays and in a urokinase-type plasminogen activator/severe combined immunodeficiency humanized mouse model of HBV infection, either alone or in combination with entecavir. RESULTS: Unlike nucleos(t)ide therapies, which reduce viremia but do not lead to an effective reduction in HBV antigen expression, RG7834 significantly reduced the levels of viral proteins (including HBsAg), as well as lowering viremia. Consistent with its proposed mechanism of action, time course RNA-seq analysis revealed a fast and selective reduction in HBV mRNAs in response to RG7834 treatment. Furthermore, oral treatment of HBV-infected humanized mice with RG7834 led to a mean HBsAg reduction of 1.09 log10 compared to entecavir, which had no significant effect on HBsAg levels. Combination of RG7834, entecavir and pegylated interferon α-2a led to significant reductions of both HBV DNA and HBsAg levels in humanized mice. CONCLUSION: We have identified a novel oral HBV viral gene expression inhibitor that blocks viral antigen and virion production, that is highly selective for HBV, and has a unique antiviral profile that is clearly differentiated from nucleos(t)ide analogues. LAY SUMMARY: We discovered a novel small molecule viral expression inhibitor that is highly selective for HBV and unlike current therapy inhibits the expression of viral proteins by specifically reducing HBV mRNAs. RG7834 can therefore potentially provide anti-HBV benefits and increase HBV cure rates, by direct reduction of viral agents needed to complete the viral life cycle, as well as a reduction of viral agents involved in evasion of the host immune responses.