The effects of selective cytokine inhibitory drugs (CC-10004 and CC-1088) on VEGF and IL-6 expression and apoptosis in myeloma and endothelial cell co-cultures

Recent developments of phosphodiesterase inhibitors: Clinical trials, emerging indications and novel molecules

The phosphodiesterase (PDE) enzymes, key regulator of the cyclic nucleotide signal transduction system, are long-established as attractive therapeutic targets. During investigation of trends within clinical trials, we have identified a particularly high number of clinical trials involving PDE inhibitors, prompting us to further evaluate the current status of this class of therapeutic agents. In total, we have identified 87 agents with PDE-inhibiting capacity, of which 85 interact with PDE enzymes as primary target. We provide an overview of the clinical drug development with focus on the current clinical uses, novel molecules and indications, highlighting relevant clinical studies. We found that the bulk of current clinical uses for this class of therapeutic agents are chronic obstructive pulmonary disease (COPD), vascular and cardiovascular disorders and inflammatory skin conditions. In COPD, particularly, PDE inhibitors are characterised by the compliance-limiting adverse reactions. We discuss efforts directed to appropriately adjusting the dose regimens and conducting structure-activity relationship studies to determine the effect of structural features on safety profile. The ongoing development predominantly concentrates on central nervous system diseases, such as schizophrenia, Alzheimer's disease, Parkinson's disease and fragile X syndrome; notable advancements are being also made in mycobacterial infections, HIV and Duchenne muscular dystrophy. Our analysis predicts the diversification of PDE inhibitors' will continue to grow thanks to the molecules in preclinical development and the ongoing research involving drugs in clinical development.

Antiangiogenic Activity of Flavonoids: A Systematic Review and Meta-Analysis

Abstract: An imbalance of angiogenesis contributes to many pathologies such as cancer, arthritis and retinopathy, hence molecules that can modulate angiogenesis are of considerable therapeutic importance. Despite many reports on the promising antiangiogenic properties of naturally occurring flavonoids, no flavonoids have progressed to the clinic for this application. This systematic review and meta-analysis therefore evaluates the antiangiogenic activities of a wide range of flavonoids and is presented in two sections. The first part of the study (Systematic overview) included 402 articles identified by searching articles published before May 2020 using ScienceDirect, PubMed and Web of Science databases. From this initial search, different classes of flavonoids with antiangiogenic activities, related pathologies and use of in vitro and/or in/ex vivo angiogenesis assays were identified. In the second part (Meta-analysis), 25 studies concerning the antiangiogenic evaluation of flavonoids using the in vivo chick chorioallantoic membrane (CAM) assay were included, following a targeted search on articles published prior to June 2020. Meta-analysis of 15 out of the 25 eligible studies showed concentration dependent antiangiogenic activity of six compared subclasses of flavonoids with isoflavones, flavonols and flavones being the most active (64 to 80% reduction of blood vessels at 100 µM). Furthermore, the key structural features required for the antiangiogenic activity of flavonoids were derived from the pooled data in a structure activity relationship (SAR) study. All in all, flavonoids are promising candidates for the development of antiangiogenic agents, however further investigations are needed to determine the key structural features responsible for their activity.

C-Myc Deregulation is Involved in Melphalan Resistance of Multiple Myeloma: Role of PDGF-BB

Oncogenes are important regulators of cancer growth and progression and their action may be modulated by proteins of the growth factor family, such as angiogenic cytokines, known to be strongly involved in neoplastic evolution. Reciprocal interactions between oncogenes and angiogenic modulators may represent, in haematological neoplasms, including multiple myeloma (MM), a possible mechanism of drug resistance. The aim of this work is to investigate in vitro and in vivo whether or not c-myc deregulation is involved in the melphalan resistance elicited by myeloma patients and consequently to clarify the role of the angiogenic factor PDGF-BB in modulating c-myc protein expression. Fifty-one MM patients on chemotherapy with melphalan were analyzed for structural alterations of the c-myc gene, c-Myc protein expression, as well as for serum PDGF-BB release. For the in vitro study, two M14-derived established cell clones, differing for the c-Myc protein expression (c-Myc low -expressing or constitutively expressing clones) were used. Our results show that PDGF-BB is able to up-regulate Myc expression and reduce melphalan sensitivity of tumor cell clones, constitutively expressing c-myc gene product. In addition, down-regulation of c-Myc protein induces the expression of PDGF-β receptor molecules and reduces PDGF-BB release. In agreement with these results, in vivo data show that melphalan-resistant MM patients present overexpressed c-Myc protein and higher serum PDGF-β receptor levels compared to minor responding patients.

PDE4 Differential Expression Is a Potential Prognostic Factor and Therapeutic Target in Patients With Myelodysplastic Syndrome and Chronic Myelomonocytic Leukemia

BACKGROUND (OR PURPOSE)

Inflammation has an essential role in the pathogenesis of myelodysplastic syndromes (MDS). Its expression is controlled by phosphodiesterase 4 (PDE4). Thus, PDE4 inhibitors might be useful therapeutic targets for MDS.

PATIENTS (OR MATERIALS) AND METHODS

We evaluated the expression of each isoform of PDE4 (A, B, C, and D) using transcriptomic profiling and examined the potential impact on the outcome of patients with MDS in terms of survival and response to hypomethylating agents. Total RNA was extracted from CD34(+) bone marrow hematopoietic cells from healthy individuals (n = 10) and patients with MDS (n = 24) or chronic myelomonocytic leukemia (n = 19).

RESULTS

The study cohort had a median follow-up period of 21.2 months (range, 0.2-68 months) and a median overall survival of 17.6 months (95% confidence interval, 9.6-25.6). The main finding of the present study was that PDE4 mean expression was generally higher in patients with MDS than in healthy individuals. Also, upregulated PDE4 expression seemed to have a possible negative effect on survival (P > .05). Moreover, lower, compared with higher, mean PDE4A and PDE4C expression is indicative of a response to a hypomethylating agent (0.09 and 0.03 vs. 0.54 and 0.49, respectively; P > .05).

CONCLUSION

These results should be confirmed in a larger patient cohort. PDE4 expression could be an effective potential prognostic factor and therapeutic target for patients with MDS and chronic myelomonocytic leukemia. The role of PDE4 inhibitors should be explored in vitro against MDS cell lines and in preclinical mouse models of MDS.

Update on the treatment of psoriasis and psoriatic arthritis - role of apremilast

Psoriatic arthritis (PsA) is an inflammatory arthritis associated with psoriasis (PsO). The treatment of PsA can be challenging and includes non-steroidal anti-inflammatory drugs, synthetic disease modifying antirheumatic drugs, and biologicals. One novel oral compound that has been recently established for the treatment of PsO and PsA is apremilast, a small molecule PDE4 inhibitor. The inhibition of PDE4 results in increased intracellular cAMP levels and modulates the expression of inflammatory mediators critically involved in PsO and PsA pathogenesis like TNF, IL-12, IL-17, and IL-23. Apremilast received US Food and Drug Administration approval for the treatment of PsO and PsA in 2014 and received approval from the European Medicines Agency in early 2015. This article summarizes the pharmacology of apremilast, its efficacy and safety in clinical studies, and its potential position in modern PsO/PsA management.

Apremilast is a selective PDE4 inhibitor with regulatory effects on innate immunity

Apremilast, an oral small molecule inhibitor of phosphodiesterase 4 (PDE4), is in development for chronic inflammatory disorders, and has shown efficacy in psoriasis, psoriatic arthropathies, and Behçet's syndrome. In March 2014, the US Food and Drug Administration approved apremilast for the treatment of adult patients with active psoriatic arthritis. The properties of apremilast were evaluated to determine its specificity, effects on intracellular signaling, gene and protein expression, and in vivo pharmacology using models of innate and adaptive immunity. Apremilast inhibited PDE4 isoforms from all four sub-families (A1A, B1, B2, C1, and D2), with IC50 values in the range of 10 to 100 nM. Apremilast did not significantly inhibit other PDEs, kinases, enzymes, or receptors. While both apremilast and thalidomide share a phthalimide ring structure, apremilast lacks the glutarimide ring and thus fails to bind to cereblon, the target of thalidomide action. In monocytes and T cells, apremilast elevated intracellular cAMP and induced phosphorylation of the protein kinase A substrates CREB and activating transcription factor-1 while inhibiting NF-κB transcriptional activity, resulting in both up- and down-regulation of several genes induced via TLR4. Apremilast reduced interferon-α production by plasmacytoid dendritic cells and inhibited T-cell cytokine production, but had little effect on B-cell immunoglobulin secretion. In a transgenic T-cell and B-cell transfer murine model, apremilast (5mg/kg/day p.o.) did not affect clonal expansion of either T or B cells and had little or no effect on their expression of activation markers. The effect of apremilast on innate immunity was tested in the ferret lung neutrophilia model, which allows monitoring of the known PDE4 inhibitor gastrointestinal side effects (nausea and vomiting). Apremilast significantly inhibited lung neutrophilia at 1mg/kg, but did not induce significant emetic reflexes at doses <30 mg/kg. Overall, the pharmacological effects of apremilast are consistent with those of a targeted PDE4 inhibitor, with selective effects on innate immune responses and a wide therapeutic index compared to its gastrointestinal side effects.

Apremilast, a novel PDE4 inhibitor, inhibits spontaneous production of tumour necrosis factor-alpha from human rheumatoid synovial cells and ameliorates experimental arthritis

Introduction

Type 4 phosphodiesterases (PDE4) play an important role in immune cells through the hydrolysis of the second messenger, cAMP. Inhibition of PDE4 has previously been shown to suppress immune and inflammatory responses, demonstrating PDE4 to be a valid therapeutic target for immune-mediated pathologies. We assessed the anti-inflammatory effects of a novel PDE4 inhibitor, apremilast, in human synovial cells from rheumatoid arthritis (RA) patients, as well as two murine models of arthritis.

Methods

Cells liberated from tissue excised from arthritic joints of RA patients were cultured in the presence of increasing concentrations of apremilast for 48 hours and spontaneous tumour necrosis factor-alpha (TNFα) production was analysed in culture supernatants by ELISA. In addition, arthritis was induced in BALB/c and DBA/1 mice by passive transfer of anti-type II collagen mAb and immunisation with type II collagen, respectively. Mice with established arthritis received 5 or 25 mg/kg apremilast and disease severity was monitored relative to mice receiving vehicle alone. At the end of the study, paws were removed and processed for histopathological assessment. Behavioural effects of apremilast, relative to rolipram, were assessed in naïve DBA/1 mice using an automated activity monitor (LABORAS).

Results

Apremilast dose dependently inhibited spontaneous release of TNFα from human rheumatoid synovial membrane cultures. Furthermore, apremilast significantly reduced clinical score in both murine models of arthritis over a ten day treatment period and maintained a healthy joint architecture in a dose-dependent manner. Importantly, unlike rolipram, apremilast demonstrated no adverse behavioural effects in naïve mice.

Conclusions

Apremilast is an orally available PDE4 inhibitor that reduces TNFα production from human synovial cells and significantly suppresses experimental arthritis. Apremilast appears to be a potential new agent for the treatment of rheumatoid arthritis.

CC-10004 but not thalidomide or lenalidomide inhibits lamina propria mononuclear cell TNF-α and MMP-3 production in patients with inflammatory bowel disease

BACKGROUND

Thalidomide, one of whose activities is to inhibit Tumour Necrosis Factor (TNF)-α production, has been reported to be an effective treatment for refractory inflammatory bowel disease (IBD). TNF-α driven production of matrix metalloproteinase (MMP)-3 by gut lamina propria mononuclear cells (LPMCs) is a major pathway of tissue injury in IBD; however the effect of thalidomide and newer more potent immunomodulatory derivatives on this pathway has not been studied.

AIM

To investigate the effect of thalidomide, CC-4047 (pomalidomide), CC-5013 (lenalidomide), and CC-10004 (apremilast) on gut LPMC TNFα and MMP-3 production in patients with IBD.

METHODS

Gut LPMCs and myofibroblasts were isolated from patients with IBD, and cultured with thalidomide, CC-4047, CC-5013, and CC-10004. MMP-3 and TIMP-1 levels were determined by western blotting and real-time PCR, and TNF-α levels by ELISA.

RESULTS

CC-10004 significantly reduced both TNF-α production and MMP-3 production by cultured LPMCs. Thalidomide and CC-4047 and CC-5013 had no significant effect on the production of TNF-α or MMP-3 by LPMCs.

CONCLUSION

These results provides a mechanistic rationale for both the failure of lenalidomide (CC-5013) in a recent randomised controlled trial in Crohn's disease, and for the evaluation of CC-10004 as a novel oral therapy in the treatment of CD and UC.

Genetic associations with thalidomide mediated venous thrombotic events in myeloma identified using targeted genotyping

A venous thromboembolism (VTE) with the subsequent risk of pulmonary embolism is a major concern in the treatment of patients with multiple myeloma with thalidomide. The susceptibility to developing a VTE in response to thalidomide therapy is likely to be influenced by both genetic and environmental factors. To test genetic variation associated with treatment related VTE in patient peripheral blood DNA, we used a custom-built molecular inversion probe (MIP)-based single nucleotide polymorphism (SNP) chip containing 3404 SNPs. SNPs on the chip were selected in "functional regions" within 964 genes spanning 67 molecular pathways thought to be involved in the pathogenesis, treatment response, and side effects associated with myeloma therapy. Patients and controls were taken from 3 large clinical trials: Medical Research Council (MRC) Myeloma IX, Hovon-50, and Eastern Cooperative Oncology Group (ECOG) EA100, which compared conventional treatments with thalidomide in patients with myeloma. Our analysis showed that the set of SNPs associated with thalidomide-related VTE were enriched in genes and pathways important in drug transport/metabolism, DNA repair, and cytokine balance. The effects of the SNPs associated with thalidomide-related VTE may be functional at the level of the tumor cell, the tumor-related microenvironment, and the endothelium. The clinical trials described in this paper have been registered as follows: MRC Myeloma IX: ISRCTN68454111; Hovon-50: NCT00028886; and ECOG EA100: NCT00033332.

Vascular endothelial growth factor and its relationship to inflammatory mediators

Inflammation occurs in response to host injury or infection, as the result of an autoimmune disease, or in response to the development of a tumor. Although the immune system may be helpful in fighting the tumor, it may also fuel the tumorigenic process. In fact, recent data suggest a strong link between chronic inflammation, angiogenesis, and the development of cancer. For example, inflammation and scarring caused by recurring infections with Mycobacterium tuberculosis may be a cause for cancers of the lung. Inflammatory breast cancer exhibits increased angiogenesis and lymphangiogenesis and has a higher metastatic potential than noninflammatory breast cancer. Nonsteroidal anti-inflammatory drugs have been proposed as preventives for the development of colon carcinoma and ovarian cancer. Inhibition of nuclear factor-kappaB contributes to the proposed mechanism of action. Inflammatory cytokines, including interleukin-6, serve as autocrine and paracrine growth factors for several cancers, and high levels of these cytokines may correlate with a poor prognosis and increased production of angiogenic factors. The state of the art of our understanding of this critical interaction is reviewed.

Protective role of wogonin against lipopolysaccharide-induced angiogenesis via VEGFR-2, not VEGFR-1

Wogonin, one of flavonoid derived from particular plants, enriches the property of anti-inflammation. Inflammation-stimulated angiogenesis plays an important role in many pathological diseases, such as rheumatoid arthritis, atherosclerosis, and cancer. The aim of this study was to investigate the suppressive effect of wogonin on lipopolysaccharide (LPS)-induced angiogenesis in human umbilical endothelial cell (HUVEC) cultures. By cell differentiation assays, migration and tube formation activity under LPS treatment were evaluated. Besides, IL-6 neutralizing antibody was added to test the inhibitory effect in the phenotypic alteration. Western blot analysis, ELISA cytokine assay, and quantitative real time-PCR were performed for VEGF, IL-6, VEGF receptors, and IL-6 receptor gene expressions on HUVEC with wogonin treatment. Furthermore, in vivo chorioallantoic membrane (CAM) assay was applied to evaluate the percentage of new vessels formation. The results revealed that wogonin (10(-8)-10(-5) M) inhibited LPS-induced angiogenesis in a concentration-dependent manner. The mRNA and protein expressions of VEGF, VEGFR-2, IL-6, and sIL-6Ralpha were attenuated (P<0.05), but not VEGFR-1. In the LPS-induced CAM model, our data suggested that wogonin (10(-8)-10(-5) M) significantly decreased new vessel formation and vascular network (P<0.05). We conclude that wogonin suppresses both in vitro and in vivo LPS-induced angiogenesis, through VEGFR-2, but not VEGFR-1.

AntiArthritis Therapies 2005

This meeting, hosted by Visiongain and B2B conferences, comprised approximately 35 delegates, predominantly from the pharmaceutical industry, and promoted interactive discussion. It covered a broad range of drug discovery and development activities, ranging from preclinical studies with compounds requiring further optimisation, through to launched drugs used in the treatment of arthritis today.