VBP15, a novel anti-inflammatory, is effective at reducing the severity of murine experimental autoimmune encephalomyelitis

Considering the Promise of Vamorolone for Treating Duchenne Muscular Dystrophy

This commentary provides an independent consideration of data related to the drug vamorolone (VBP15) as an alternative steroid proposed for treatment of Duchenne muscular dystrophy (DMD). Glucocorticoids such as prednisone and deflazacort have powerful anti-inflammatory benefits and are the standard of care for DMD, but their long-term use can result in severe adverse side effects; thus, vamorolone was designed as a unique dissociative steroidal anti-inflammatory drug, to retain efficacy and minimise these adverse effects. Extensive clinical trials (ongoing) have investigated the use of vamorolone for DMD, with two trials also for limb-girdle muscular dystrophies including dysferlinopathy (current), plus a variety of pre-clinical trials published. Vamorolone looks very promising, with similar efficacy and some reduced adverse effects (e.g., related to height) compared with other glucocorticoids, specifically prednisone/prednisolone, although it has not yet been directly compared with deflazacort. Of particular interest to clarify is the optimal clinical dose and other aspects of vamorolone that are proposed to provide additional benefits for membranes of dystrophic muscle: to stabilise and protect the sarcolemma from damage and enhance repair. The use of vamorolone (and other glucocorticoids) needs to be evaluated in terms of overall long-term efficacy and cost, and also in comparison with many candidate non-steroidal drugs with anti-inflammatory and other benefits for DMD.

The Effect of Immunomodulatory Treatments on Anti-Dystrophin Immune Response After AAV Gene Therapy in Dystrophin Deficient mdx Mice

BACKGROUND

AAV-based gene therapy is an attractive approach to treat Duchenne muscular dystrophy (DMD) patients. Although the long-term consequences of a gene therapy approach for DMD are unknown, there is evidence in both DMD patients and animal models that dystrophin replacement by gene therapy leads to an anti-dystrophin immune response that is likely to limit the long-term use of these therapeutic strategies.

OBJECTIVE

Our objective is to test whether the anti-dystrophin immune response is affected by immunomodulatory drugs in mdx mice after rAAV gene therapy.

METHODS

mdx mice were treated with rAAV microdystrophin alone or in combination with immunomodulatory drugs. Dystrophin expression in skeletal muscle was assessed by mass spectrometry. Immune responses were assessed by immunophenotyping, western blot for anti-dystrophin antibodies and flow cytometry assays for antigen-specific T-cell cytokine expression. The impact on muscle was measured by grip strength assessment, in vivo torque, optical imaging for inflammation and H&E staining of sections to assess muscle damage.

RESULTS

We found that AAV-9-microdystrophin gene therapy induced expression of microdystrophin, anti-dystrophin antibodies, and T-cell cytokine responses. Immunomodulatory treatments, rituximab and VBP-6 completely abrogated the anti-dystrophin antibody response. Prednisolone, CTLA4-Ig, and Eplerenone showed variable efficacy in blocking the anti-dystrophin immune response. In contrast, none of the drugs completely abrogated the antigen specific IFN-γ response. AAV-microdystrophin treatment significantly reduced inflammation in both forelimbs and hindlimbs, and the addition of prednisolone and VBP6 further reduced muscle inflammation. Treatment with immunomodulatory drugs, except eplerenone, enhanced the beneficial effects of AAV-microdystrophin therapy in terms of force generation.

CONCLUSIONS

Our data suggest that AAV-microdystrophin treatment results in anti-dystrophin antibody and T-cell responses, and immunomodulatory treatments have variable efficacy on these responses.

A comparative study of melatonin and immunomodulatory therapy with interferon beta and glatiramer acetate in a mouse model of multiple sclerosis

INTRODUCTION

Multiple sclerosis (MS) is a chronic, demyelinating, autoimmune disease of the central nervous system causing neuroinflammation. Experimental autoimmune encephalitis (EAE) is a model of the disease. MS is classically treated with interferon beta (IFN-β) and glatiramer acetate (GA). Melatonin (MLT) has been reported to modulate immune system responses. The aim of the present study is to analyse the effects of MLT administration in comparison with the first-line treatments for MS (IFN-β and GA).

METHODS

EAE was induced in male Sprague-Dawley rats; the animals subsequently received either IFN-β, GA, or MLT. Cerebrospinal fluid (CSF) samples were analysed by multiplex assay to determine the levels of proinflammatory cytokines. The neurological evaluation of EAE was also recorded.

RESULTS

All immunised animals developed EAE. We evaluated the first relapse-remission cycle, observing that IFN-β and GA had better results than MLT in the clinical evaluation. Neither EAE nor any of the treatments administered modified CSF IL-1β and IL-12p70 concentrations. However, IFN-β and MLT did decrease CSF TNF-α concentrations.

CONCLUSIONS

Further studies are needed to evaluate the molecular mechanisms involved in the behaviour of MLT in EAE, and to quantify other cytokines in different biological media in order for MLT to be considered an anti-inflammatory agent capable of regulating MS.

Efficacy and safety of vamorolone in Duchenne muscular dystrophy: An 18-month interim analysis of a non-randomized open-label extension study

BACKGROUND

Treatment with corticosteroids is recommended for Duchenne muscular dystrophy (DMD) patients to slow the progression of weakness. However, chronic corticosteroid treatment causes significant morbidities. Vamorolone is a first-in-class anti-inflammatory investigational drug that has shown evidence of efficacy in DMD after 24 weeks of treatment at 2.0 or 6.0 mg/kg/day. Here, open-label efficacy and safety experience of vamorolone was evaluated over a period of 18 months in trial participants with DMD.

METHODS AND FINDINGS

A multicenter, open-label, 24-week trial (VBP15-003) with a 24-month long-term extension (VBP15-LTE) was conducted by the Cooperative International Neuromuscular Research Group (CINRG) and evaluated drug-related effects of vamorolone on motor outcomes and corticosteroid-associated safety concerns. The study was carried out in Canada, US, UK, Australia, Sweden, and Israel, from 2016 to 2019. This report covers the initial 24-week trial and the first 12 months of the VBP15-LTE trial (total treatment period 18 months). DMD trial participants (males, 4 to <7 years at entry) treated with 2.0 or 6.0 mg/kg/day vamorolone for the full 18-month period (n = 23) showed clinical improvement of all motor outcomes from baseline to month 18 (time to stand velocity, p = 0.012 [95% CI 0.010, 0.068 event/second]; run/walk 10 meters velocity, p < 0.001 [95% CI 0.220, 0.491 meters/second]; climb 4 stairs velocity, p = 0.001 [95% CI 0.034, 0.105 event/second]; 6-minute walk test, p = 0.001 [95% CI 31.14, 93.38 meters]; North Star Ambulatory Assessment, p < 0.001 [95% CI 2.702, 6.662 points]). Outcomes in vamorolone-treated DMD patients (n = 46) were compared to group-matched participants in the CINRG Duchenne Natural History Study (corticosteroid-naïve, n = 19; corticosteroid-treated, n = 68) over a similar 18-month period. Time to stand was not significantly different between vamorolone-treated and corticosteroid-naïve participants (p = 0.088; least squares [LS] mean 0.042 [95% CI -0.007, 0.091]), but vamorolone-treated participants showed significant improvement compared to group-matched corticosteroid-naïve participants for run/walk 10 meters velocity (p = 0.003; LS mean 0.286 [95% CI 0.104, 0.469]) and climb 4 stairs velocity (p = 0.027; LS mean 0.059 [95% CI 0.007, 0.111]). The vamorolone-related improvements were similar in magnitude to corticosteroid-related improvements. Corticosteroid-treated participants showed stunting of growth, whereas vamorolone-treated trial participants did not (p < 0.001; LS mean 15.86 [95% CI 8.51, 23.22]). Physician-reported incidences of adverse events (AEs) for Cushingoid appearance, hirsutism, weight gain, and behavior change were less for vamorolone than published incidences for prednisone and deflazacort. Key limitations to the study were the open-label design, and use of external comparators.

CONCLUSIONS

We observed that vamorolone treatment was associated with improvements in some motor outcomes as compared with corticosteroid-naïve individuals over an 18-month treatment period. We found that fewer physician-reported AEs occurred with vamorolone than have been reported for treatment with prednisone and deflazacort, and that vamorolone treatment did not cause the stunting of growth seen with these corticosteroids. This Phase IIa study provides Class III evidence to support benefit of motor function in young boys with DMD treated with vamorolone 2.0 to 6.0 mg/kg/day, with a favorable safety profile. A Phase III RCT is underway to further investigate safety and efficacy.

TRIAL REGISTRATION

Clinical trials were registered at www.clinicaltrials.gov, and the links to each trial are as follows (as provided in manuscript text): VBP15-002 [NCT02760264] VBP15-003 [NCT02760277] VBP15-LTE [NCT03038399].

Exposure-Response Analysis of Vamorolone (VBP15) in Boys With Duchenne Muscular Dystrophy

Exposure-response relationships of vamorolone, a novel dissociative steroidal anti-inflammatory drug, were investigated in clinical trials in boys with Duchenne muscular dystrophy. Variables were clinical outcome measures, Fridericia-corrected QT (QTcF) duration, and pharmacodynamic (PD) biomarkers. Exposure metrics were area under the plasma concentration time curve (AUC) and maximum plasma concentration (C_max ), with a sigmoid E_max model applied. Significant improvement in clinical efficacy outcomes was observed after 24 weeks of daily dosing. The primary outcome, time to stand from supine velocity, exhibited the highest sensitivity to vamorolone, with the lowest AUC value providing 50% of maximum effect (E₅₀  = 186 ng·h/mL), followed by time to climb 4 stairs (E₅₀  = 478 ng·h/mL), time to run/walk 10 m (E₅₀  = 1220 ng·h/mL), and 6-minute walk test (E₅₀  = 1770 ng·h/mL). Week 2 changes of proinflammatory PD biomarkers showed exposure-dependent decreases. The E₅₀ was 260 ng·h/mL for insulin-like growth factor-binding protein 2, 1200 ng·h/mL for matrix metalloproteinase 12, 1260 ng·h/mL for lymphotoxin α1/β2, 1340 ng·h/mL for CD23, 1420 ng·h/mL for interleukin-22-binding protein, and 1600 ng·h/mL for macrophage-derived chemokine/C-C motif chemokine 22. No relationship was found between QTcF interval changes from baseline and C_max in week 2 or 24. This analysis showed that improvements in clinical efficacy end points in week 24 and PD biomarkers in week 2 were achieved at typical vamorolone exposure of 2 mg/kg daily dose with a median AUC dose of 6 mg/kg (3651 ng·h/mL), corresponding to approximately 95% of maximum effects for most response variables.

Vamorolone trial in Duchenne muscular dystrophy shows dose-related improvement of muscle function

Objective

To study vamorolone, a first-in-class steroidal anti-inflammatory drug, in Duchenne muscular dystrophy (DMD).

Methods

An open-label, multiple-ascending-dose study of vamorolone was conducted in 48 boys with DMD (age 4–<7 years, steroid-naive). Dose levels were 0.25, 0.75, 2.0, and 6.0 mg/kg/d in an oral suspension formulation (12 boys per dose level; one-third to 10 times the glucocorticoid dose in DMD). The primary goal was to define optimal doses of vamorolone. The primary outcome for clinical efficacy was time to stand from supine velocity.

Results

Oral administration of vamorolone at all doses tested was safe and well tolerated over the 24-week treatment period. The 2.0–mg/kg/d dose group met the primary efficacy outcome of improved muscle function (time to stand; 24 weeks of vamorolone treatment vs natural history controls), without evidence of most adverse effects of glucocorticoids. A biomarker of bone formation, osteocalcin, increased in vamorolone-treated boys, suggesting possible loss of bone morbidities seen with glucocorticoids. Biomarker outcomes for adrenal suppression and insulin resistance were also lower in vamorolone-treated patients with DMD relative to published studies of glucocorticoid therapy.

Conclusions

Daily vamorolone treatment suggested efficacy at doses of 2.0 and 6.0 mg/kg/d in an exploratory 24-week open-label study.

Classification of evidence

This study provides Class IV evidence that for boys with DMD, vamorolone demonstrated possible efficacy compared to a natural history cohort of glucocorticoid-naive patients and appeared to be tolerated.

Vamorolone, a dissociative steroidal compound, reduces collagen antibody-induced joint damage and inflammation when administered after disease onset

OBJECTIVE AND DESIGN

The objective of this study was to assess the effect of vamorolone, a first-in-class dissociative steroidal compound, to inhibit inflammation when administered after disease onset in the murine collagen antibody-induced arthritis model of arthritis.

ANIMALS

84 DBA1/J mice were used in this study (n = 12 per treatment group).

TREATMENT

Vamorolone or prednisolone was administered orally after disease onset for a duration of 7 days.

METHODS

Disease score and bone erosion were assessed using previously described scoring systems. Cytokines were measured in joints via immunoassay, and joint cathepsin B activity (marker of inflammation) was assessed using optical imaging of joints on live mice.

RESULTS

We found that vamorolone treatment led to a reduction of several disease parameters including disease score, joint inflammation, and the presence of pro-inflammatory mediators to a degree similar of that observed with prednisolone treatment. More importantly, histopathological analysis of affected joints showed that vamorolone treatment significantly reduced the degree of bone erosion while this bone-sparing property was not observed with prednisolone treatment at any of the tested doses.

CONCLUSIONS

While many intervention regimens in other studies are administered prior to disease onset in animal models, the current study involves delivery of the potential therapeutic after disease onset. Based on the findings, vamorolone may offer an efficacious, yet safer alternative to conventional steroidal compounds in the treatment of rheumatoid arthritis and other inflammatory diseases.

Two-Year Longitudinal Changes in Lower Limb Strength and Its Relation to Loss in Function in a Large Cohort of Patients With Duchenne Muscular Dystrophy

OBJECTIVE

The main objective of this study was to examine the effect of disease on strength in two functionally important lower limb muscles for a period of 2 yrs in children with Duchene muscular dystrophy.

DESIGN

Seventy-seven Duchene muscular dystrophy children participated in this study. Plantar flexors, knee extensors, strength, and performance on timed tests (6-min walk, 4-stairs, 10-m walk, supine-up) were assessed yearly for 2 yrs. Multivariate normal regression was used to assess changes in strength over time in the Duchene muscular dystrophy group. Spearman correlations were computed to examine relationship between strength and function.

RESULTS

Normalized plantar flexor and knee extensor strength showed a significant decrease (P < 0.05) over 2 yrs, with larger declines in knee extensor. At baseline, knee extensor strongly correlated with performance on timed tests. However, plantar flexor strength was found to be a stronger predictor of loss in ambulatory function. Modest correlations (r = 0.19-0.34) were found between the decline in strength and functional performance over 2 yrs.

CONCLUSIONS

This study describes the loss of lower limb strength in a large cohort of Duchene muscular dystrophy children for 2 yrs. The findings support that lower limb strength alone cannot account for the decline in performance on functional tests, and the role of other contributing factors, such as compensatory strategies, should be considered.

Population Pharmacokinetics of Vamorolone (VBP15) in Healthy Men and Boys With Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is an inherited neuromuscular disorder occurring in boys and caused by mutations in the dystrophin gene. Vamorolone is a first-generation delta-9,11 compound that has favorable efficacy and side effect profiles relative to classical glucocorticoids. The pharmacokinetics (PK) of oral vamorolone were assessed in parallel-group studies in healthy men (phase 1, n = 86) and boys with DMD (phase 2a, n = 48) during 14 days of once-daily dosing with a range of doses. Vamorolone exhibited moderate variability in PK, with the maximum plasma concentration usually occurring at 2-4 hours and a half-life of approximately 2 hours for all doses and days examined. Population PK modeling of all data together indicated that the PK of vamorolone can be well described by a 1-compartment model with zero-order absorption. Both men and boys showed a dose-linearity of PK parameters for the doses examined, with no accumulation of the drug during daily dosing. Ingestion with food resulted in markedly enhanced absorption of the drug, as tested in healthy men. There were similar PK of vamorolone in healthy men and DMD boys with apparent clearance averaging 2.0 L/h/kg in men and 1.7 L/h/kg in boys. Overall, vamorolone exhibited well-behaved linear PK, with similar profiles in healthy men and boys with DMD, moderate variability in PK parameters, and absorption and disposition profiles similar to those of classical glucocorticoids.

Vamorolone targets dual nuclear receptors to treat inflammation and dystrophic cardiomyopathy

Cardiomyopathy is a leading cause of death for Duchenne muscular dystrophy. Here, we find that the mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) can share common ligands but play distinct roles in dystrophic heart and skeletal muscle pathophysiology. Comparisons of their ligand structures indicate that the Δ9,11 modification of the first-in-class drug vamorolone enables it to avoid interaction with a conserved receptor residue (N770/N564), which would otherwise activate transcription factor properties of both receptors. Reporter assays show that vamorolone and eplerenone are MR antagonists, whereas prednisolone is an MR agonist. Macrophages, cardiomyocytes, and CRISPR knockout myoblasts show vamorolone is also a dissociative GR ligand that inhibits inflammation with improved safety over prednisone and GR-specific deflazacort. In mice, hyperaldosteronism activates MR-driven hypertension and kidney phenotypes. We find that genetic dystrophin loss provides a second hit for MR-mediated cardiomyopathy in Duchenne muscular dystrophy model mice, as aldosterone worsens fibrosis, mass and dysfunction phenotypes. Vamorolone successfully prevents MR-activated phenotypes, whereas prednisolone activates negative MR and GR effects. In conclusion, vamorolone targets dual nuclear receptors to treat inflammation and cardiomyopathy with improved safety.

Vamorolone treatment improves skeletal muscle outcome in a critical illness myopathy rat model

AIM

Critical illness myopathy (CIM) is a consequence of modern critical care, leading to skeletal muscle atrophy/paralysis with negative consequences for mortality/morbidity and health care costs. Glucocorticoids (GCs) have been proposed to trigger CIM. Here, we compare outcomes of two GCs, the commonly used prednisolone and the newly developed dissociative vamorolone in response to the intensive care unit (ICU) condition for 5 days, ie, sedation, immobilization, and mechanical ventilation.

METHODS

Rats were divided into a 0-day sham-operated control group, and three groups exposed to 5 days ICU condition during treatment with prednisolone (PRED) or vamorolone (VAM) or none of these GCs (ICU-group). Survival, body and muscle weights, cytokine concentrations, regulation of muscle contraction in single fast- and slow-twitch muscle fibres, myofibrillar protein expression and protein degradation pathways were studied.

RESULTS

Critical illness myopathy geno- and pheno-types were confirmed in the ICU group. However, VAM and PRED groups showed reduced atrophy/weakness than the ICU group, and muscle specific differences with more severe negative effects on fast-twitch muscle fibres in the PRED than the other groups.

CONCLUSION

These results show that vamorolone provides a GC intervention superior to typical GCs in improving CIM outcomes. Further, the findings do not support the notion that moderate-dose GC treatment represents a factor triggering CIM.

Phase IIa trial in Duchenne muscular dystrophy shows vamorolone is a first-in-class dissociative steroidal anti-inflammatory drug

We report a first-in-patient study of vamorolone, a first-in-class dissociative steroidal anti-inflammatory drug, in Duchenne muscular dystrophy. This 2-week, open-label Phase IIa multiple ascending dose study (0.25, 0.75, 2.0, and 6.0 mg/kg/day) enrolled 48 boys with Duchenne muscular dystrophy (4 to <7 years), with outcomes including clinical safety, pharmacokinetics and pharmacodynamic biomarkers. The study design included pharmacodynamic biomarkers in three contexts of use: 1. Secondary outcomes for pharmacodynamic safety (insulin resistance, adrenal suppression, bone turnover); 2. Exploratory outcomes for drug mechanism of action; 3. Exploratory outcomes for expanded pharmacodynamic safety. Vamorolone was safe and well-tolerated through the highest dose tested (6.0 mg/kg/day) and pharmacokinetics of vamorolone were similar to prednisolone. Using pharmacodynamic biomarkers, the study demonstrated improved safety of vamorolone versus glucocorticoids as shown by reduction of insulin resistance, beneficial changes in bone turnover (loss of increased bone resorption and decreased bone formation only at the highest dose level), and a reduction in adrenal suppression. Exploratory biomarkers of pharmacodynamic efficacy showed an anti-inflammatory mechanism of action and a beneficial effect on plasma membrane stability, as demonstrated by a dose-responsive decrease in serum creatine kinase activity. With an array of pre-selected biomarkers in multiple contexts of use, we demonstrate the development of the first dissociative steroid that preserves anti-inflammatory efficacy and decreases steroid-associated safety concerns. Ongoing extension studies offer the potential to bridge exploratory efficacy biomarkers to clinical outcomes.

Phase 1 trial of vamorolone, a first-in-class steroid, shows improvements in side effects via biomarkers bridged to clinical outcomes

BACKGROUND

Glucocorticoid drugs are highly effective anti-inflammatory agents, but chronic use is associated with extensive pharmacodynamic safety concerns that have a considerable negative impact on patient quality of life.

PURPOSE

Vamorolone (VBP15) is a first-in-class steroidal multi-functional drug that shows potent inhibition of pro-inflammatory NFkB pathways via high-affinity binding to the glucocorticoid receptor, high affinity antagonism for the mineralocorticoid receptor, and membrane stabilization properties. Pre-clinical data in multiple mouse models of inflammation showed retention of anti-inflammatory efficacy, but loss of most or all side effects.

EXPERIMENTAL APPROACH

We report first-in-human Phase 1 clinical trials (86 healthy adult males), with single ascending doses (0.1-20.0 mg/kg), and multiple ascending doses (1.0-20 mg/kg/day; 14 days treatment).

KEY RESULTS

Vamorolone was well-tolerated at all dose levels. Vamorolone showed pharmacokinetic and metabolism profiles similar to prednisone. Biomarker studies showed loss of side effects of traditional glucocorticoid drugs (bone fragility, metabolic disturbance, immune suppression). Suppression of the adrenal axis was 10-fold less than prednisone. The crystallographic structure of vamorolone was solved, and compared to prednisone and dexamethasone. There was overlap in structure, but differences in conformation at the C-ring where glucocorticoids interact with Asn564 of the glucocorticoid receptor. The predicted loss of Asn564 binding to vamorolone may underlie the loss of gene transcriptional activity.

CONCLUSIONS AND INTERPRETATIONS

Vamorolone is a dissociative steroid that retains high affinity binding and nuclear translocation of both glucocorticoid (agonist) and mineralocorticoid (antagonist) receptors, but does not show pharmacodynamic safety concerns of existing glucocorticoid drugs at up to 20 mg/kg/day.

Therapeutic Potential of Pien Tze Huang on Experimental Autoimmune Encephalomyelitis Rat

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system (CNS). There is still lack of commercially viable treatment currently. Pien Tze Huang (PZH), a traditional Chinese medicine, has been proved to have anti-inflammatory, neuroprotective, and immunoregulatory effects. This study investigated the possible therapeutic effects of PZH on experimental autoimmune encephalomyelitis (EAE) rats, a classic animal model of MS. Male Lewis rats were immunized with myelin basic protein (MBP) peptide to establish an EAE model and then treated with three doses of PZH. Clinical symptoms, organ coefficient, histopathological features, levels of proinflammatory cytokines, and chemokines as well as MBP and Olig2 were analyzed. The results indicated that PZH ameliorated the clinical severity of EAE rats. It also remarkably reduced inflammatory cell infiltration in the CNS of EAE rats. Furthermore, the levels of IL-17A, IL-23, CCL3, and CCL5 in serum and the CNS were significantly decreased; the p-P65 and p-STAT3 levels were also downregulated in the CNS, while MBP and Olig2 in the CNS of EAE rats had a distinct improvement after PZH treatment. In addition, PZH has no obvious toxicity at the concentration of 0.486 g/kg/d. This study demonstrated that PZH could be used to treat MS.

Vamorolone, a dissociative steroidal compound, reduces pro-inflammatory cytokine expression in glioma cells and increases activity and survival in a murine model of cortical tumor

Corticosteroids, such as dexamethasone, are routinely used as palliative care in neuro-oncology for their anti-inflammatory benefits, however many patients experience dose limiting side effects caused by glucocorticoid response element (GRE)-mediated transcription. The purpose of this study was to use a murine model to investigate a new steroid alternative, vamorolone, which promises to reduce side effects through dissociating GRE-mediated transcription and NF-κB -mediated anti-inflammatory actions. To compare vamorolone to dexamethasone in reducing pro-inflammatory signals in vitro, murine glioma cells were treated with dexamethasone, vamorolone or vehicle control. Changes in mRNA expression were assessed using the nanostring inflammatory platform. Furthermore, drug efficacy, post-treatment behavioral activity and side effects were assessed by treating two cohorts of brain tumor bearing mice with dexamethasone, vamorolone, or vehicle control. Our investigation showed that treatment with vamorolone resulted in a reduction of pro-inflammatory signals in tumor cells in vitro similar to treatment with dexamethasone. Treatment with vamorolone resulted in a better safety profile in comparison to dexamethasone treatment. Vamorolone- treated mice showed similar or better activity and survival when compared to dexamethasone-treated mice. Our data indicate vamorolone is a potential steroid-sparing alternative for treating patients with brain tumors.

OPN-a induces muscle inflammation by increasing recruitment and activation of pro-inflammatory macrophages

New Findings

What is the central question of this study?

What is the functional relevance of OPN isoform expression in muscle pathology?

What is the main finding and its importance?

The full‐length human OPN‐a isoform is the most pro‐inflammatory isoform in the muscle microenvironment, acting on macrophages and myoblasts in an RGD‐integrin‐dependent manner. OPN‐a upregulates expression of tenascin‐C (TNC), a known Toll‐like receptor 4 (TLR4) agonist. Blocking TLR4 signalling inhibits the pro‐inflammatory effects of OPN‐a, suggesting that a potential mechanism of OPN action is by promoting TNC–TLR4 signalling.

Although osteopontin (OPN) is an important mediator of muscle remodelling in health and disease, functional differences in human spliced OPN variants in the muscle microenvironment have not been characterized. We thus sought to define the pro‐inflammatory activities of human OPN isoforms (OPN‐a, OPN‐b and OPN‐c) on cells present in regenerating muscle. OPN transcripts were quantified in normal and dystrophic human and dog muscle. Human macrophages and myoblasts were stimulated with recombinant human OPN protein isoforms, and cytokine mRNA and protein induction was assayed. OPN isoforms were greatly increased in dystrophic human (OPN‐a > OPN‐b > OPN‐c) and dog muscle (OPN‐a = OPN‐c). In healthy human muscle, mechanical loading also upregulated OPN‐a expression (eightfold; P < 0.01), but did not significantly upregulate OPN‐c expression (twofold; P > 0.05). In vitro, OPN‐a displayed the most pronounced pro‐inflammatory activity among isoforms, acting on both macrophages and myoblasts. In vitro and in vivo data revealed that OPN‐a upregulated tenascin‐C (TNC), a known Toll‐like receptor 4 (TLR4) agonist. Inhibition of TLR4 signalling attenuated OPN‐mediated macrophage cytokine production. In summary, OPN‐a is the most abundant and functionally active human spliced isoform in the skeletal muscle microenvironment. Here, OPN‐a promotes pro‐inflammatory signalling in both macrophages and myoblasts, possibly through induction of TNC–TLR4 signalling. Together, our findings suggest that specific targeting of OPN‐a and/or TNC signalling in the damaged muscle microenvironment may be of therapeutic relevance.

VBP15, a novel dissociative steroid compound, reduces NFκB-induced expression of inflammatory cytokines in vitro and symptoms of murine trinitrobenzene sulfonic acid-induced colitis

OBJECTIVE AND DESIGN

The goal of this study was to assess the capacity of VBP15, a dissociative steroidal compound, to reduce pro-inflammatory cytokine expression in vitro, to reduce symptoms of colitis in the trinitrobenzene sulfonic acid-induced murine model, and to assess the effect of VBP15 on growth stunting in juvenile mice.

MATERIALS

In vitro studies were performed in primary human intestinal epithelial cells. Colitis was induced in mice by administering trinitrobenzene sulfonic acid. Growth stunting studies were performed in wild type outbred mice.

TREATMENT

Cells were treated with VBP15 or prednisolone (10 μM) for 24 h. Mice were subjected to 3 days of VBP15 (30 mg/kg) or prednisolone (30 mg/kg) in the colitis study. In the growth stunting study, mice were subjected to VBP15 (10, 30, 45 mg/kg) or prednisolone (10 mg/kg) for 5 weeks.

METHODS

Cytokines were measured by PCR and via Luminex. Colitis symptoms were evaluated by assessing weight loss, intestinal blood, and stool consistency. Growth stunting was assessed using an electronic caliper.

RESULTS

VBP15 significantly reduced the in vitro production of CCL5 (p < 0.001) IL-6 (p < 0.001), IL-8 (p < 0.05) and reduced colitis symptoms (p < 0.05). VBP15 caused less growth stunting than prednisolone (p < 0.001) in juvenile mice.

CONCLUSION

VBP15 may reduce symptoms of IBD, while decreasing or avoiding detrimental side effects.

A novel dissociative steroid VBP15 reduces MUC5AC gene expression in airway epithelial cells but lacks the GRE mediated transcriptional properties of dexamethasone

Overproduction of secretory mucins contributes to morbidity/mortality in inflammatory lung diseases. Inflammatory mediators directly increase expression of mucin genes, but few drugs have been shown to directly repress mucin gene expression. IL-1β upregulates the MUC5AC mucin gene in part via the transcription factors NFκB while the glucocorticoid Dexamethasone (Dex) transcriptionally represses MUC5AC expression by Dex-activated GR binding to two GRE cis-sites in the MUC5AC promoter in lung epithelial cells. VBP compounds (ReveraGen BioPharma) maintain anti-inflammatory activity through inhibition of NFκB but exhibit reduced GRE-mediated transcriptional properties associated with adverse side-effects and thus have potential to minimize harmful side effects of long-term steroid therapy in inflammatory lung diseases. We investigated VBP15 efficacy as an anti-mucin agent in two types of airway epithelial cells and analyzed the transcription factor activity and promoter binding associated with VBP15-induced MUC5AC repression. VBP15 reduced MUC5AC mRNA abundance in a dose- and time-dependent manner similar to Dex in the presence or absence of IL-1β in A549 and differentiated human bronchial epithelial cells. Repression was abrogated in the presence of RU486, demonstrating a requirement for GR in the VBP15-induced repression of MUC5AC. Inhibition of NFκB activity resulted in reduced baseline expression of MUC5AC indicating that constitutive activity maintains MUC5AC production. Chromatin immunoprecipitation analysis demonstrated lack of GR and of p65 (NFκB) binding to composite GRE domains in the MUC5AC promoter following VBP15 exposure of cells, in contrast to Dex. These data demonstrate that VBP15 is a novel anti-mucin agent that mediates the reduction of MUC5AC gene expression differently than the classical glucocorticoid, Dex.

Pharmacologically-induced mitotic synchrony in airway epithelial cells as a mechanism of action of anti-inflammatory drugs

BACKGROUND

Mitotic synchrony is the synchronous progression of a population of cells through the cell cycle and is characteristic of non-diseased airway epithelial cells. However, we previously showed that asthmatic airway epithelial cells are characterized by mitotic asynchrony and are pro-inflammatory as a result. Glucocorticoids can induce mitotic synchrony that in turn suppresses the pro-inflammatory state of diseased cells, suggesting a novel anti-inflammatory mechanism of action. Herein, we benchmarked traditional glucocorticoids against the ability of a new clinical-stage dissociative steroidal drug, VBP15, for mitotic resynchronization and associated anti-inflammatory activity in asthmatic airway epithelial cells.

METHODS

Primary airway epithelial cells differentiated at air-liquid interface were exposed to VBP15, dexamethasone or vehicle following in vitro mechanical injury. Basolateral cytokine secretions (TGF-β1, IL-6, IL-10, IL-13, and IL-1β) were analyzed at different time points using cytometric bead assays and mitosis was examined by flow cytometry.

RESULTS

VBP15 improved mitotic synchrony of proliferating asthmatic cells in air-liquid interface cultures compared to vehicle-exposed cultures. VBP15 also significantly reduced the basolateral secretion of pro-inflammatory (i.e. IL-1β) and pro-fibrogenic cytokines (i.e. TGF-β1) in air-liquid interface-differentiated asthmatic epithelial cultures following mechanical injury.

CONCLUSION

VBP15 improves mitotic asynchrony and injury-induced pro-inflammatory and fibrogenic responses in asthmatic airway epithelial cultures with efficacy comparable to traditional glucocorticoids. As it is predicted to show superior side effect profiles compared to traditional glucocorticoids, VBP15 holds potential for treatment of asthma and other respiratory conditions.