Rationale and early clinical data on IL-17 blockade in psoriasis

Role of IL-17 in plaque psoriasis: therapeutic potential of ixekizumab

Developments in the understanding of the immunopathogenesis of psoriasis have identified interleukin (IL)-17 as the key proinflammatory cytokine in the pathogenesis of plaque psoriasis, with the consequent development of drugs that target this cytokine or associated receptors. Ixekizumab is a subcutaneously administered humanized monoclonal antibody, which acts to neutralize IL-17A. This article reviews the role of IL-17 in the pathogenesis of psoriasis, the biological and pharmacokinetics of ixekizumab and the safety profile and the clinical efficacy of ixekizumab in Phase III clinical trials. Phase III clinical trials of ixekizumab have so far demonstrated excellent early clinical efficacy, with a comparable safety profile to the existing biologic therapies for psoriasis. To further assess its position in the treatment algorithm for psoriasis, a further head to head RCT with secukinumab could be established, alongside comparative effectiveness studies from observational research. In addition, trials are needed to assess its role in those with tumor necrosis factor inhibitors/ustekinumab resistant disease. However, it is clear that the IL-17 antagonists have changed the benchmark for clinical efficacy, and it is likely that ixekizumab along with the other IL-17 antagonists are set to achieve a new standard of care in the treatment of moderate to severe plaque psoriasis.

Population Pharmacokinetic Modeling of Secukinumab in Patients With Moderate to Severe Psoriasis

Secukinumab is a human monoclonal antibody with demonstrated efficacy for moderate to severe psoriasis; it binds to and neutralizes interleukin (IL)-17A. The pharmacokinetic (PK) parameters of secukinumab were best described by a 2-compartment model. Only weight was included in the final model, as other covariates did not affect clinical relevance. The estimated serum clearance of secukinumab was 0.19 L/day, with interindividual variability (IIV) of 32% coefficient of variation (CV), and low total volume of distribution (central compartment volume, 3.61 L with IIV of 30% CV; peripheral compartment volume, 2.87 L with IIV of 18% CV). The bioavailability of secukinumab after subcutaneous dosing was approximately 73%, with an absorption rate of 0.18/day with IIV of 35% CV. The PK profile of secukinumab was linear, with no evidence of a dose dependence of clearance. Clearance and volume of secukinumab varied with body weight in an allometric relationship. The time to maximum serum concentration at steady state occurred approximately 6 days after dosing for both secukinumab 300 mg and secukinumab 150 mg. Overall, the PK properties of secukinumab were typical of a 150-kDa human IgG1 antibody interacting with a soluble target.

Biologic Therapy in the Treatment of Chronic Skin Disorders

Understanding of the immunologic pathways involved in the pathogenesis of skin-related diseases is constantly advancing. Several biologic agents play important therapeutic roles for management of patients with chronic urticaria, atopic dermatitis, and psoriasis, particularly omalizumab for antihistamine-resistant chronic urticaria, interleukin (IL)-1 inhibitors for cryopyrin-associated periodic syndrome and Schnitzler syndrome, dupilumab for recalcitrant atopic dermatitis, and IL-17 inhibitors for psoriasis. The therapeutic utility of biologic agents for patients with immune-related dermatologic disorders is likely to expand in the future. This article reviews the data regarding biologic agents and their utility in the management of specific skin-related disorders.

Interleukin-17 inhibitors. A new era in treatment of psoriasis and other skin diseases

Psoriasis is a chronic skin disease caused by the excessive secretion of inflammatory cytokines. Available therapeutic options include biologic drugs such as tumor necrosis factor alpha inhibitors and interleukin 12/23 (IL-12/23) inhibitors. The recent discovery of IL-17, which contributes to development of psoriasis, opened new possibilities for further treatment modalities. Currently, one anti-IL17 biological agent is approved for the treatment – a fully human monoclonal antibody that targets IL-17A (secukinumab). Further clinical trials, including a humanized IgG4 specific for IL-17 (ixekizumab) and a fully human antibody that targets the IL-17 receptor A (brodalumab).

Lipoprotein Metabolism and Inflammation in Patients With Psoriasis

Psoriasis is a chronic inflammatory disease associated with a variety of co-morbid conditions, including cardiovascular disease. Advancements in our understanding of the cellular and molecular mechanisms of psoriasis have led to a better understanding regarding its pathogenesis, which in turn has stimulated ongoing research to identify the underlying pathophysiology responsible for the increased risk of cardiovascular events associated with psoriasis. Although not yet fully elucidated, emerging evidence points to immune-mediated inflammation as a process that contributes to endothelial cell dysfunction, dyslipidemia, and atherosclerosis as key processes influencing cardiovascular disease in psoriasis. In particular, the dyslipidemia present in psoriasis may be associated with altered lipoprotein function and increased atherogenicity. Here, we review how the cytokine networks involved in lipoprotein metabolism and inflammation could impact on the cardiovascular disease risk for patients with psoriasis.

IL-23/IL-17A Dysfunction Phenotypes Inform Possible Clinical Effects from Anti-IL-17A Therapies

Biologics that neutralize specific cytokines have improved outcomes for several immune-mediated disorders but may also increase risks for particular side effects. This article postulates potential immunologic consequences of inhibiting components of the IL-23/T-helper cell 17 pathway–the target of next-generation biologics for treating psoriasis–based on clinical phenotypes of inherent or acquired deficiencies in this pathway. Generally, downstream deficiencies (e.g., IL-17A, IL-17F) are associated with fewer disorders compared with upstream deficiencies, suggesting that selectively blocking downstream targets may result in a narrower range of side effects. However, safety of these specific inhibitions must be established in long-term studies.

Clinical potential of brodalumab in the management of psoriasis: the evidence to date

Brodalumab is an anti-IL-17 receptor monoclonal antibody currently in development for the treatment of moderate-to-severe plaque psoriasis. With many systemic psoriasis therapies to choose from, and several newer agents in development, physicians need up to date evidence for the use of these drugs. A PubMed search was conducted through August 1, 2014 to identify randomized controlled trials and systematic reviews of brodalumab for the treatment of psoriasis. Results of Phase I and II trials, as well as a few smaller studies, have provided promising data on efficacy, safety, health-related quality of life, pharmacokinetics, and changes in lesional skin. Early Phase III data continue to support the use of brodalumab as a potentially valuable option for the treatment of psoriasis.

Cytokines plasma levels during antidepressant treatment with sertraline and transcranial direct current stimulation (tDCS): results from a factorial, randomized, controlled trial

RATIONALE

The inflammatory hypothesis of depression states that increased levels of pro-inflammatory cytokines triggered by external and internal stressors are correlated to the acute depressive state. This hypothesis also suggests that pharmacotherapy partly acts in depression through anti-inflammatory effects. Transcranial direct current stimulation (tDCS) is a novel, promising, non-invasive somatic treatment for depression, although its antidepressant mechanisms are only partly understood.

OBJECTIVES

We explored the effects of tDCS and sertraline over the immune system during an antidepressant treatment trial.

METHODS

In a 6-week, double-blind, placebo-controlled trial, 73 antidepressant-free patients with unipolar depression were randomized to active/sham tDCS and sertraline/placebo (2 × 2 design). Plasma levels of several cytokines (IL-2, IL-4, IL-6, IL-10, IL-17a, IFN-γ, and TNF-α) were determined to investigate the effects of the interventions and of clinical response on them.

RESULTS

All cytokines, except TNF-α, decreased over time, these effects being similar across the different intervention-groups and in responders vs. non-responders.

CONCLUSIONS

tDCS and sertraline (separately and combined) acute antidepressant effects might not specifically involve normalization of the immune system. In addition, being one of the first placebo-controlled trials measuring cytokines over an antidepressant treatment course, our study showed that the decrease in cytokine levels during the acute depressive episode could involve a placebo effect, highlighting the need of further placebo-controlled trials and observational studies examining cytokine changes during depression treatment and also after remission of the acute depressive episode.