Apremilast mechanism of action and application to psoriasis and psoriatic arthritis. Biochem Pharmacol. 2012;83:1583-1590. [PMID: 22257911 DOI: 10.1016/j.bcp.2012.01.001]

Psoriatic arthritis: latest treatments and their place in therapy

Psoriatic arthritis (PsA) is a heterogeneous chronic inflammatory disease that may affect peripheral and axial joints, entheses, skin and nails, and other organs. Treatment with nonsteroidal anti-inflammatory drugs, steroid and disease-modifying antirheumatic drugs had been the backbone of traditional management of PsA for many years. However, improvement in our understanding of immunopathogenesis of PsA has led to new immunomodulatory therapies. Introduction of novel agents has raised the bar for treatment and helped drive research into additional therapeutic options.

The pharmacodynamic impact of apremilast, an oral phosphodiesterase 4 inhibitor, on circulating levels of inflammatory biomarkers in patients with psoriatic arthritis: substudy results from a phase III, randomized, placebo-controlled trial (PALACE 1)

Apremilast, an oral phosphodiesterase 4 inhibitor, demonstrated effectiveness (versus placebo) for treatment of active psoriatic arthritis in the psoriatic arthritis long-term assessment of clinical efficacy (PALACE) phase III clinical trial program. Pharmacodynamic effects of apremilast on plasma biomarkers associated with inflammation were evaluated in a PALACE 1 substudy. Of 504 patients randomized in PALACE 1, 150 (placebo: n = 51; apremilast 20 mg BID: n = 51; apremilast 30 mg BID: n = 48) provided peripheral blood plasma samples for analysis in a multiplexed cytometric bead array assay measuring 47 proteins associated with systemic inflammatory immune responses. Association between biomarker levels and achievement of 20% improvement from baseline in modified American College of Rheumatology (ACR20) response criteria was assessed by logistic regression. At Week 24, IL-8, TNF-α, IL-6, MIP-1β, MCP-1, and ferritin were significantly reduced from baseline with apremilast 20 mg BID or 30 mg BID versus placebo. ACR20 response correlated with change in TNF-α level with both apremilast doses. At Week 40, IL-17, IL-23, IL-6, and ferritin were significantly decreased and IL-10 and IL-1 receptor antagonists significantly increased with apremilast 30 mg BID versus placebo. In patients with active psoriatic arthritis, apremilast reduced circulating levels of Th1 and Th17 proinflammatory mediators and increased anti-inflammatory mediators.

The immunopathology of cutaneous lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that is characterized by the development of autoantibodies and immunologic attack of different organ systems, including the skin. This review aims to provide an overview of some of the pathogenic processes that may be important in the development of SLE, specifically cutaneous lupus erythematosus, and then illustrates how therapies might be tailored to modify these processes and treat disease.

Longterm (52-week) results of a phase III randomized, controlled trial of apremilast in patients with psoriatic arthritis

OBJECTIVE

To evaluate the efficacy and safety of apremilast, an oral phosphodiesterase 4 inhibitor, over 52 weeks in patients with active psoriatic arthritis (PsA) despite prior treatment.

METHODS

Patients were randomized to placebo (n = 168), apremilast 20 mg BID (n = 168), or apremilast 30 mg BID (n = 168). Patients whose swollen and tender joint counts had not improved by ≥ 20% at Week 16 were considered nonresponders and were required to be re-randomized (1:1) to apremilast 20 mg BID or 30 mg BID if they were initially randomized to placebo, or continued their initial treatment of apremilast dose. At Week 24, all remaining patients treated with placebo were re-randomized to apremilast 20 mg BID or 30 mg BID.

RESULTS

An American College of Rheumatology 20 (ACR20) response at Week 16 was attained by significantly more patients receiving apremilast 20 mg BID (30.4%, p = 0.0166) or 30 mg BID (38.1%, p = 0.0001) than placebo (19.0%). Among patients receiving apremilast continuously for 52 weeks (n = 254), ACR20 response at Week 52 was observed in 63.0% (75/119, 20 mg BID) and 54.6% (71/130, 30 mg BID) of patients. Response was also maintained across secondary outcomes, including measures of PsA signs and symptoms, skin psoriasis severity, and physical function. The nature, incidence, and severity of adverse events were comparable over the 24-week and 52-week periods. The most common adverse events, diarrhea and nausea, generally occurred early and were self-limited.

CONCLUSION

Continuous apremilast treatment resulted in sustained improvements in PsA for up to 52 weeks. Apremilast had an acceptable safety profile and was generally well tolerated.

CLINICAL TRIAL REGISTRATION

NCT01172938.

Inhibitors of phosphodiesterase 4 (PDE 4): A new therapeutic option in the treatment of psoriasis vulgaris and psoriatic arthritis

Psoriasis vulgaris and psoriatic arthritis are inflammatory diseases in which inflammation and sustained inducing lesions result from immune disorders associated with overactivity of T cells that produce multiple proinflammatory cytokines, including tumor necrosis factor alpha (TNF-α) and interleukin (IL): IL-2, IL-12, IL-17, IL-22 or IL-23. Modern treatment of these diseases is focused on reducing the inflammatory process responsible for the development of the disease. In recent years, the treatment of psoriasis is developing at a dynamic rate. Such therapeutic advances are contributed to the possibility of patient therapy through the use of some registered biologic agents, such as TNF-α inhibitors (infliximab, etanercept and adalimumab), and an inhibitor of the p40 subunit common to IL-12 and IL-23 (ustekinumab). In addition to the already registered medications for the indications mentioned above, there is a large group of preparations that are currently undergoing clinical trials in Europe, Canada and the United States, which provides hopes of therapy efficacy and safety.

The translational revolution and use of biologics in patients with inflammatory skin diseases

Psoriasis and atopic dermatitis (AD) are common inflammatory skin diseases characterized by immune-mediated inflammation and abnormal keratinocyte differentiation. Although T-cell infiltration characterizes both diseases, T-cell polarization differs. Psoriasis is currently the best model for translational medicine because many targeted therapeutics have been developed and testing of targeted therapeutics has cemented psoriasis as IL-23/TH17 polarized. In patients with AD, although therapeutic development is approximately a decade behind that in patients with psoriasis, there is now active development and testing of targeted therapeutics against various immune axes (TH2, TH22, and IL-23/TH17). These clinical trials and subsequent molecular analyses using human samples will be able to clarify the relative roles of polar cytokines in patients with AD.

Treatment of spondyloarthritis beyond TNF-alpha blockade

The advent of biologics targeting tumor necrosis factor-alpha (TNF-alpha) has revolutionized the field of rheumatology in general and the treatment of spondyloarthritis (SpA) in particular, since - apart from non-steroidal anti-inflammatory agents - no disease modifying treatments are available for this frequent, inflammatory rheumatic condition. The significant improvements in signs and symptoms observed with TNF-blockers in this group of diseases, have raised the bar with regard to treatment goals, including clinical remission. Even if treatment failure with TNF-blocking agents may be a relatively rare phenomenon, cases of primary non-responders, secondary loss-of-efficacy and intolerance, have been described. Results with abatacept, rituximab and tocilizumab - all effective in the treatment of rheumatoid arthritis - were disappointing, especially in patients that had previously failed anti-TNF therapy. On the other hand, there is increasing evidence that targeting the cytokines of the Th-17 axis is associated with major improvements of skin psoriasis and its associated arthritis. In axial spondyloarthritis, preliminary proof-of-concept studies with ustekinumab and interleukin-17 targeting therapies suggest that these agents could become the first new treatment options, not targeting TNF. Finally, the advent of small molecules targeting inflammatory, intracellular signalling pathways, may further change our future therapeutic approach.

The impact of co-administration of ketoconazole and rifampicin on the pharmacokinetics of apremilast in healthy volunteers

AIMS

Two clinical studies were conducted to determine possible drug-drug interactions between apremilast and a strong CYP3A4 inhibitor, ketoconazole, or a potent CYP3A4 inducer, rifampicin. The main objectives of these two studies were to evaluate the impact of multiple doses of ketoconazole on the pharmacokinetics of apremilast and its metabolites, and the effect of multiple oral doses of rifampicin on the pharmacokinetics of apremilast.

METHODS

These single centre, open label, sequential treatment studies in healthy subjects included two treatment periods for ketoconazole and three treatment periods for rifampicin. Apremilast was administered as a 20 mg (ketoconazole study) or 30 mg (rifampicin study) single oral dose.

RESULTS

Ketoconazole increases overall exposure (AUC(0,∞)) of apremilast by ≈36% (2827 vs. 2072 ng ml(-1)  h, 90% CI = 126.2, 147.5) and peak exposure (Cmax ) by 5% (247 vs. 236 ng ml(-1) ). Multiple doses of rifampicin increase apremilast clearance ≈3.6-fold and decrease apremilast mean AUC(0,∞) by ≈72% (3120 vs. 869 ng ml(-1)  h, 90% CI = 25.7, 30.4) and Cmax (from 290 vs. 166 ng ml(-1) ) relative to that of apremilast given alone. A 30 min intravenous infusion of rifampicin 600 mg had negligible effects on the overall exposure (AUC(0,∞)) of apremilast (2980 vs. 3120 ng ml(-1)  h, 90% CI = 88.0, 104.1).

CONCLUSION

Ketoconazole slightly decreased apremilast clearance, resulting in a small increase in AUC which is probably not meaningful clinically. However, the effect of CYP3A4 induction by rifampicin on apremilast clearance is much more pronounced than that of CYP3A4 inhibition by ketoconazole. Strong CYP3A4 inducers may result in a loss of efficacy of apremilast because of decreased drug exposure.

The pharmacokinetic effect of coadministration of apremilast and methotrexate in individuals with rheumatoid arthritis and psoriatic arthritis

Apremilast is a novel agent for the treatment of inflammatory based autoimmune disorders. The objective of this study was to assess the pharmacokinetic effects of co administration of apremilast and methotrexate on both agents. This was an open-label, multi-center, 3-treatment period, sequential study conducted in otherwise healthy subjects with psoriatic arthritis or rheumatoid arthritis who were receiving a stable oral dose of methotrexate between 7.5 to 20 mg once weekly. Subjects received their dose of methotrexate on Days 1 and 8 of the study in addition to Apremilast 30 mg oral every 12 hours on Days 3-8. Pharmacokinectic profiles of methotrexate and 7-OH methotrexate were characterized after methotrexate alone (Day 1) and after co-administration of methotrexate and Apremilast (on Day 8). The pharmacokinetic profile of Apremilast was characterized after Apremilast alone (on Day 7) and after co-administration of methotrexate and Apremilast (on Day 8). The 90% confidence interval of the ratio of the geometric means for the Cmax and AUC parameters for methotrexate, 7-OH methotrexate, and Apremilast alone and after co-adminstration are all within the FDA acceptance range for equivalency (80-125%). This study showed that methotrexate and apremilast can be co-administered without any effect on the pharmacokinetic exposure of either agent.

Small-molecule inhibitors for autoimmune arthritis: success, failure and the future

Treatment of patients with aggressive autoimmune arthritis, such as rheumatoid arthritis (RA), is a considerable challenge for physicians, particularly rheumatologists. Because of the nature of autoimmune arthritis, effective and complete suppression of disease activity has been the primary therapeutic goal. Although currently available disease-modifying antirheumatic drugs (DMARDs) can successfully control the disease progression in a large proportion of patients, the benefit/risk ratio is not very much satisfied. The introduction of biologic agents such as anti-tumor necrosis factor-α, anti-interleukin-6, and anti-CD20 brings significant help to those patients with an inadequate response to treatment with DMARDs. In considering the limitation of currently available DMARDs and biologics, the development of new DMARDs, small-molecule inhibitors (SMIs), has recently emerged. In the past few years, a great volume of knowledge has been revealed from the experience of examining the usefulness of several SMIs for therapeutics of autoimmune arthritis. This paper addresses the up-to-date knowledge regarding autoimmune arthritis, therapeutics, findings from recently developed SMIs and the benefits and drawbacks of the development of SMIs. In addition, perspectives on the future development of SMIs for autoimmune arthritis will be described and discussed.

Small-molecule control of cytokine function: new opportunities for treating immune disorders

Manipulating cytokine function with protein-based drugs has proven effective for treating a wide variety of autoimmune and autoinflammatory disorders. However, the limited ability of protein-based drugs to modulate intracellular targets, including many implicated by studies of the genetics and physiology of these diseases, and to coordinately neutralize redundant inflammatory cytokines, suggests an important and complementary role for small molecules in immunomodulatory drug development. The recent clinical approval of Janus kinase and phosphodiesterase inhibitors, along with emerging evidence from other compound classes, firmly establish small molecules as effective tools for modulating therapeutically relevant proteins that give rise to aberrant cytokine signaling or mediate its downstream consequences.

Therapeutic targeting of the inflammome

Inflammatory responses can vary depending on a myriad of factors including: (1) the initiating stimulus or trigger, (2) the cell types involved in the response, and (3) the specific effector cytokine-chemokine milieus produced. The compilation of these and other factors in a given mechanistic context is sometimes referred to as the "inflammome". Humans and other higher-order mammals have evolved (over time) several discrete inflammomes to counter the effects of pathogens. However, when these inflammomes are induced inappropriately, they drive the development of chronic inflammatory diseases. The vast majority of biological anti-inflammatory treatments currently being developed are focused on the post hoc inhibition of downstream effectors by anti-cytokine monoclonal antibodies and receptor antagonists. This prevailing "end-point treatment" has even directed a new disease classification paradigm, namely a cytokine-based disease classification, as opposed to a traditional diagnosis based on a particular tissue or organ system dysfunction. Although this approach has a number of advantages, it omits the processes that led to the generation of the inflammatory effectors in the first place. In this review, we will expand the cytokine-based disease taxonomy into an inflammome-based taxonomy that includes interventions that subvert a priori cytokine development and can complement post hoc inhibition.

Apremilast

Each month, subscribers to The Formulary Monograph Service receive 5 to 6 well-documented monographs on drugs that are newly released or are in late phase 3 trials. The monographs are targeted to Pharmacy & Therapeutics Committees. Subscribers also receive monthly 1-page summary monographs on agents that are useful for agendas and pharmacy/nursing in-services. A comprehensive target drug utilization evaluation/medication use evaluation (DUE/MUE) is also provided each month. With a subscription, the monographs are sent in print and are also available on-line. Monographs can be customized to meet the needs of a facility. A drug class review is now published monthly with The Formulary Monograph Service. Through the cooperation of The Formulary, Hospital Pharmacy publishes selected reviews in this column. For more information about The Formulary Monograph Service, call The Formulary at 800-322-4349. The September 2014 monograph topics are tedizolid phosphate, ceritinib, omega-3-carboxylic acids, umeclidinium bromide inhalation powder, and siltuximab. The DUE/MUE is on avoidance of insulin use errors.

Chronic inflammatory diseases: do immunological patterns drive the choice of biotechnology drugs? A critical review

Chronic inflammatory diseases represent a heterogeneous group of conditions that can affect practically any organ or system. An increasing number of biologic agents have been developed to selectively target the cell populations and signaling pathways involved in chronic inflammation, including cytokines, monoclonal antibodies and engineered receptors. This approach has been remarkably successful in alleviating some of the signs and symptoms of refractory autoimmune diseases. The use of this therapeutic strategy is likely to increase with the introduction of biosimilar agents. The different nature of these biological products makes the comparison of their pharmaceutical and clinical characteristics difficult, including safety and potency and these issues may be particularly relevant in the case of biosimilars. In addition, the heterogeneity of autoimmune diseases and of autoimmune patients, further adds to the complexity of choosing the right drug for each patient and predicting efficacy and safety of the treatment. In this review, we summarize actual knowledge about current biological agents and their use in autoimmune diseases, with a special emphasis for rheumatoid arthritis, inflammatory bowel diseases and psoriasis. The purpose of this analysis is to address the most critical issues raised by the rapid advancements in this field over recent years, and to acknowledge the potentially valuable gains brought about by the increasing availability of these new biologic agents.

Treatment of psoriatic arthritis in a phase 3 randomised, placebo-controlled trial with apremilast, an oral phosphodiesterase 4 inhibitor

OBJECTIVES

Apremilast, an oral phosphodiesterase 4 inhibitor, regulates inflammatory mediators. Psoriatic Arthritis Long-term Assessment of Clinical Efficacy 1 (PALACE 1) compared apremilast with placebo in patients with active psoriatic arthritis despite prior traditional disease-modifying antirheumatic drug (DMARD) and/or biologic therapy.

METHODS

In the 24-week, placebo-controlled phase of PALACE 1, patients (N=504) were randomised (1:1:1) to placebo, apremilast 20 mg twice a day (BID) or apremilast 30 mg BID. At week 16, patients without ≥20% reduction in swollen and tender joint counts were required to be re-randomised equally to either apremilast dose if initially randomised to placebo or remained on their initial apremilast dose. Patients on background concurrent DMARDs continued stable doses (methotrexate, leflunomide and/or sulfasalazine). Primary outcome was the proportion of patients achieving 20% improvement in modified American College of Rheumatology response criteria (ACR20) at week 16.

RESULTS

At week 16, significantly more apremilast 20 mg BID (31%) and 30 mg BID (40%) patients achieved ACR20 versus placebo (19%) (p<0.001). Significant improvements in key secondary measures (physical function, psoriasis) were evident with both apremilast doses versus placebo. Across outcome measures, the 30-mg group generally had higher and more consistent response rates, although statistical comparison was not conducted. The most common adverse events were gastrointestinal and generally occurred early, were self-limiting and infrequently led to discontinuation. No imbalance in major adverse cardiac events, serious or opportunistic infections, malignancies or laboratory abnormalities was observed.

CONCLUSIONS

Apremilast was effective in the treatment of psoriatic arthritis, improving signs and symptoms and physical function. Apremilast demonstrated an acceptable safety profile and was generally well tolerated.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01172938.

[New aspects on the pathogenesis of psoriatic arthritis]

Psoriasis and psoriatic arthritis (PsA) are immune-mediated inflammatory diseases with a high burden of disability and increased mortality. The pathogenesis of the disease comprises a dysregulated interaction between stromal and immune cells and a dysfunctional cytokine network supporting chronic inflammation of the skin, entheses and joints. In addition to recent advances in the understanding of TNF blockade, more targets have been discovered delivering insights into the pathogenesis of PsA. This article gives a translational approach by utilizing current clinical development programs providing an insight into the IL-12/IL-23 and the IL-17 axes and also focuses on tissue damage and new small molecules.

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.

Pharmacogenetics of topical and systemic treatment of psoriasis

Psoriasis is a chronic inflammatory skin disease. The cause of psoriasis is unknown, although genetics may play a key role in its development. Treatment of the disease varies with severity. Topical drugs, such as corticosteroids, coal tar, retinoids and vitamin D analogs, are commonly used to treat mild psoriasis. Phototherapy and systemic drugs, such as calcineurin inhibitors, methotrexate, acitretin and biological drugs, are usually used to treat moderate-to-severe psoriasis. Not all patients respond well to treatment, and some can develop severe adverse effects. Interindividual differences in several genes may explain this variation in response to treatment. Pharmacogenetics and pharmacogenomics can facilitate more personalized medicine and prevent the adverse effects associated with treatment.

Therapeutic strategies in psoriasis patients with psoriatic arthritis: focus on new agents

Psoriatic arthritis affects approximately 6-42 % of patients with psoriasis. It is useful for physicians or dermatologists managing psoriasis patients to be aware of how to concurrently manage the joint manifestations, as it is preferable and convenient to use a single agent in such patients. However, only certain therapies are effective for both. Systemic agents, which can be used for both skin and joint manifestations, include methotrexate and ciclosporin. For the group of biologic agents, the tumor necrosis factor inhibitors such as adalimumab, etanercept, infliximab, golimumab and certolizumab are effective. Ustekinumab is a more recently developed agent belonging to the group of anti-IL-12p40 antibodies and has been shown to be efficacious. Newer drugs in the treatment armamentarium that have shown efficacy for both psoriasis and psoriatic arthritis consist of the anti-IL-17 agent, secukinumab, and a phosphodiesterase-4 inhibitor, apremilast. The other anti-IL-17 agents, ixekizumab and brodalumab, as well as the oral Jak inhibitor, tofacitinib, have very limited but promising data. This review paper provides a good overview of the agents that can be used for the concurrent management of skin and joint psoriasis.

Genetics of psoriasis and pharmacogenetics of biological drugs

Psoriasis is a chronic inflammatory disease of the skin. The causes of psoriasis are unknown, although family and twin studies have shown genetic factors to play a key role in its development. The many genes associated with psoriasis and the immune response include TNFα, IL23, and IL12. Advances in knowledge of the pathogenesis of psoriasis have enabled the development of new drugs that target cytokines (e.g., etanercept, adalimumab, and infliximab, which target TNFα, and ustekinumab, which targets the p40 subunit of IL23 and IL12). These drugs have improved the safety and efficacy of treatment in comparison with previous therapies. However, not all patients respond equally to treatment, possibly owing to interindividual genetic variability. In this review, we describe the genes associated with psoriasis and the immune response, the biological drugs used to treat chronic severe plaque psoriasis, new drugs in phase II and III trials, and current knowledge on the implications of pharmacogenomics in predicting response to these treatments.

Phosphodiesterase 4 inhibition in the treatment of psoriasis, psoriatic arthritis and other chronic inflammatory diseases

Agents which increase intracellular cyclic adenosine monophosphate (cAMP) may have an antagonistic effect on pro-inflammatory molecule production so that inhibitors of the cAMP degrading phosphodiesterases have been identified as promising drugs in chronic inflammatory disorders. Although many such inhibitors have been developed, their introduction in the clinic has been hampered by their narrow therapeutic window with side effects such as nausea and emesis occurring at sub-therapeutic levels. The latest generation of inhibitors selective for phosphodiesterase 4 (PDE4), such as apremilast and roflumilast, seems to have an improved therapeutic index. While roflumilast has been approved for the treatment of exacerbated chronic obstructive pulmonary disease (COPD), apremilast shows promising activity in dermatological and rheumatological conditions. Studies in psoriasis and psoriatic arthritis have demonstrated clinical activity of apremilast. Efficacy in psoriasis is probably equivalent to methotrexate but less than that of monoclonal antibody inhibitors of tumour necrosis factor (TNFi). Similarly, in psoriatic arthritis efficacy is less than that of TNF inhibitors. PDE4 inhibitors hold the promise to broaden the portfolio of anti-inflammatory therapeutic approaches in a range of chronic inflammatory diseases which may include granulomatous skin diseases, some subtypes of chronic eczema and probably cutaneous lupus erythematosus. In this review, the authors highlight the mode of action of PDE4 inhibitors on skin and joint inflammatory responses and discuss their future role in clinical practice. Current developments in the field including the development of topical applications and the development of PDE4 inhibitors which specifically target the subform PDE4B will be discussed.

New developments in the management of psoriasis and psoriatic arthritis: a focus on apremilast

Psoriasis is a chronic inflammatory skin disease, most commonly resulting in the occurrence of red and silver scaly plaques. About 30% of psoriasis sufferers develop psoriatic arthritis (PsA), a disorder that presents with additional joint inflammation and other clinical features. At present, the most effective treatment for moderate and severe psoriasis and PsA are biologics such as antitumor necrosis factor alpha therapy. Biologics are costly and typically require repeated injections; hence, the development of novel, orally available, small molecular inhibitors that are less expensive to produce is highly desirable. The phosphodiesterase 4 inhibitor apremilast is a small molecular inhibitor that acts by increasing cyclic adenosine monophosphate levels, ultimately suppressing tumor necrosis alpha production. Apremilast has been tested in a number of psoriasis and PsA pilot and Phase II trials to evaluate its efficacy and safety. More recently, three larger double-blinded, and randomized multicenter studies demonstrate that apremilast is efficacious in the treatment of psoriasis and PsA, with significantly higher numbers of apremilast-treated patients achieving endpoints of a 75% reduction compared to baseline in Psoriasis Area and Severity Index (PASI-75) or American College of Rheumatology-20 scores, relative to placebo. This encouraging data, along with a tolerable incidence of mild to moderate adverse events, has led to the initiation of several large Phase III trials that aim to further validate apremilast as a treatment for psoriasis and PsA. Here, we provide an overview of the current treatments for psoriasis and PsA, and summarize the findings from multiple Phase II clinical trials where the effects of apremilast in the treatment of psoriasis and PsA patients have been investigated.

Naturally derived anti-inflammatory compounds from Chinese medicinal plants

ETHNOPHARMACOLOGICAL RELEVANCE

Though inflammatory response is beneficial to body damage repair, if it is out of control, it can produce adverse effects on the body. Although purely western anti-inflammatory drugs, orthodox medicines, can control inflammation occurrence and development, it is not enough. The clinical efficacy of anti-inflammation therapies is unsatisfactory, thus the search for new anti-inflammation continues. Chinese Material Medica (CMM) remains a promising source of new therapeutic agents. CMM and herbal formulae from Traditional Chinese Medicine (TCM), unorthodox medicines, play an improtant anti-inflammatory role in multi-targets, multi-levels, and multi-ways in treating inflammation diseases in a long history in China, based on their multi-active ingredient characteristics. Due to these reasons, recently, CMM has been commercialized as an anti-inflammation agent which has become increasingly popular in the world health drug markets. Major research contributions in ethnopharmacology have generated vast amount of data associated with CMM in anti-inflammtion aspect. Therefore, a systematic introduction of CMM anti-inflammatory research progress is of great importance and necessity.

AIM OF THE STUDY

This paper strives to describe the progress of CMM in the treatment of inflammatory diseases from different aspects, and provide the essential theoretical support and scientific evidence for the further development and utilization of CMM resources as a potential anti-inflammation drug through a variety of databases.

MATERIAL AND METHODS

Literature survey was performed via electronic search (SciFinder®, Pubmed®, Google Scholar and Web of Science) on papers and patents and by systematic research in ethnopharmacological literature at various university libraries.

RESULTS

This review mainly introduced the current research on the anti-inflammatory active ingredient, anti-inflammatory effects of CMM, their mechanism, anti-inflammatory drug development of CMM, and toxicological information.

CONCLUSION

CMM is used clinically to treat inflammation symptoms in TCM, and its effect is mediated by multiple targets through multiple active ingredients. Although scholars around the world have made studies on the anti-inflammatory studies of CMM from different pathways and aspects and have made substantial progress, further studies are warranted to delineate the inflammation actions in more cogency models, establish the toxicological profiles and quality standards, assess the potentials of CMM in clinical applications, and make more convenient preparations easy to administrate for patients. Development of the clinically anti-inflammatory drugs are also warranted.

Steps in the management of psoriatic arthritis: a guide for clinicians

Psoriatic arthritis is a common systemic inflammatory disorder, which in addition to skin and nail involvement may be associated with peripheral and axial joint involvement, enthesitis, dactylitis, and important comorbidities - especially cardiovascular morbidity. Better insights into the involved pathogenic mechanisms have resulted in an improved therapeutic armamentarium, which targets key pathways in its pathogenesis. This has resulted in significant clinical responses to newer therapeutic agents, especially those directed at inhibition of tumor necrosis factor α. Biological therapy leads to significant levels of remission, improved quality of life, and retards or improves structural radiological damage.

Hyperbaric oxygen preconditioning protects skin from UV-A damage

Hyperbaric oxygen therapy (HBOT) is used for a number of applications, including the treatment of diabetic foot ulcers and CO poisoning. However, we and others have shown that HBOT can mobilize cellular antioxidant defenses, suggesting that it may also be useful under circumstances in which tissue protection from oxidative damage is desired. To test the protective properties of hyperbaric oxygen (HBO) on a tissue level, we evaluated the ability of a preconditioning treatment regimen to protect cutaneous tissue from UV-A-induced oxidative damage. Three groups of hairless SKH1-E mice were exposed to UV-A 3 days per week for 22 weeks, with two of these groups receiving an HBO pretreatment either two or four times per week. UV-A exposure increased apoptosis and proliferation of the skin tissue, indicating elevated levels of epithelial damage and repair. Pretreatment with HBO significantly reduced UV-A-induced apoptosis and proliferation. A morphometric analysis of microscopic tissue folds also showed a significant increase in skin creasing following UV-A exposure, which was prevented by HBO pretreatment. Likewise, skin elasticity was found to be greatest in the group treated with HBO four times per week. The effects of HBO were also apparent systemically as reductions in caspase-3 activity and expression were observed in the liver. Our findings support a protective function of HBO pretreatment from a direct oxidative challenge of UV-A to skin tissue. Similar protection of other tissues may likewise be achievable.

Altered bone biology in psoriatic arthritis

Psoriatic arthritis (PsA) is characterized by focal bone erosions mediated by osteoclasts at the bone-pannus junction. The bulk of research over the past decade has centered on mechanisms that underlie osteoclastogenesis along with new insights into osteoimmunology; however, recent advances that focus on steps that lead to new bone formation are beginning to emerge. New revelations about bone formation may have direct relevance to PsA given the presence of enthesophytes, syndesmophytes, and bony ankylosis frequently observed in patients with this disorder. In this review, we discuss current developments in the pathogenesis of new bone formation, novel imaging approaches to study bone remodeling and highlight innovative approaches to study the effect of inflammation on bone. Lastly, we discuss promising therapies that target joint inflammation and osteitis with the potential to mediate pathologic bone formation.