HLA-Cw6 allele, NFkB1 and NFkBIA polymorphisms play no role in predicting response to etanercept in psoriatic patients

From Manifestations to Innovations: A Deep Dive into Psoriasis, its Clinical Diversity, Conventional Treatments, and Emerging Therapeutic Paradigms

Psoriasis, a persistent inflammatory dermatological illness, places a significant load on those affected, requiring ongoing investigation into innovative therapies. This review examines the significance of pre-clinical models in defining our comprehension of psoriasis, as well as the valuable insights obtained from clinical trials that aid in developing treatment approaches. The evaluation includes existing established medicines such as topicals, phototherapy, and traditional systemic drugs targeting different pathological mediators of psoriasis. Further, emerging frontiers in the treatment of psoriasis are examined, including personalized medicine, novel biologics, small molecule inhibitors, and advanced delivery methods. The objective is to identify potential advancements that can be applied in clinical practice to the patients. In light of current knowledge, this review delineates what are perceived as critical future research directions and noteworthy therapeutic and clinical developments in the domain of psoriasis.

Profiling CARD14 gene expression in Indian Psoriasis patients

Several Genome Wide linkage Studies on psoriasis performed to gain insight of genetic architecture of the disease. Caspase Recruitment Domain-containing family 14 (CARD14) also known as CARMA2 or BIMP2; cytogenic location: 17q25.3, is a scaffold protein that primarily controls the skin epidermis's nuclear factor kB (NF-kB) signaling pathway activity in skin epidermis, a master gene for inflammation, has been shown to be linked with rare, heritable form of psoriasis. CARD14 is predominantly expressed in keratinocytes and epithelial cells, but also in unidentified dermal cells. For better understanding of molecular processes involved in CARD14 underlying Indian psoriatic patients, we analyzed gene expression of 42 moderates to severe cases of plaque psoriasis and same number of controls using qPCR and its validation through Immunohistochemistry (IHC). This study identifies that the expression of CARD14 in dermal endothelial cells among patients with psoriasis and explores the potential functional consequences associated with an overactive CARD14 gene. Furthermore, the expression data from the western population was consistent with the results of the qPCR validation of the candidate gene. There is a significant correlation between Indian psoriasis vulgaris patients and CARD14 up-regulation, as evidenced by a roughly two-fold shift in lesional tissue expression. This provides insights into the pathways and genes linked to the pathogenesis of psoriasis.

The Association between Genetics and Response to Treatment with Biologics in Patients with Psoriasis, Psoriatic Arthritis, Rheumatoid Arthritis, and Inflammatory Bowel Diseases: A Systematic Review and Meta-Analysis

Genetic biomarkers could potentially lower the risk of treatment failure in chronic inflammatory diseases (CID) like psoriasis, psoriatic arthritis (PsA), rheumatoid arthritis (RA), and inflammatory bowel disease (IBD). We performed a systematic review and meta-analysis assessing the association between single nucleotide polymorphisms (SNPs) and response to biologics. Odds ratio (OR) with 95% confidence interval (CI) meta-analyses were performed. In total, 185 studies examining 62,774 individuals were included. For the diseases combined, the minor allele of MYD88 (rs7744) was associated with good response to TNFi (OR: 1.24 [1.02-1.51], 6 studies, 3158 patients with psoriasis or RA) and the minor alleles of NLRP3 (rs4612666) (OR: 0.71 [0.58-0.87], 5 studies, 3819 patients with RA or IBD), TNF-308 (rs1800629) (OR: 0.71 [0.55-0.92], 25 studies, 4341 patients with psoriasis, RA, or IBD), FCGR3A (rs396991) (OR: 0.77 [0.65-0.93], 18 studies, 2562 patients with psoriasis, PsA, RA, or IBD), and TNF-238 (rs361525) (OR: 0.57 [0.34-0.96]), 7 studies, 818 patients with psoriasis, RA, or IBD) were associated with poor response to TNFi together or infliximab alone. Genetic variants in TNFα, NLRP3, MYD88, and FcRγ genes are associated with response to TNFi across several inflammatory diseases. Most other genetic variants associated with response were observed in a few studies, and further validation is needed.

Genetic Influence on Treatment Response in Psoriasis: New Insights into Personalized Medicine

Psoriasis is a chronic inflammatory disease with an established genetic background. The HLA-Cw*06 allele and different polymorphisms in genes involved in inflammatory responses and keratinocyte proliferation have been associated with the development of the disease. Despite the effectiveness and safety of psoriasis treatment, a significant percentage of patients still do not achieve adequate disease control. Pharmacogenetic and pharmacogenomic studies on how genetic variations affect drug efficacy and toxicity could provide important clues in this respect. This comprehensive review assessed the available evidence for the role that those different genetic variations may play in the response to psoriasis treatment. One hundred fourteen articles were included in this qualitative synthesis. VDR gene polymorphisms may influence the response to topical vitamin D analogs and phototherapy. Variations affecting the ABC transporter seem to play a role in methotrexate and cyclosporine outcomes. Several single-nucleotide polymorphisms affecting different genes are involved with anti-TNF-α response modulation (TNF-α, TNFRSF1A, TNFRSF1B, TNFAIP3, FCGR2A, FCGR3A, IL-17F, IL-17R, and IL-23R, among others) with conflicting results. HLA-Cw*06 has been the most extensively studied allele, although it has only been robustly related to the response to ustekinumab. However, further research is needed to firmly establish the usefulness of these genetic biomarkers in clinical practice.

Impact of Functional Polymorphisms on Drug Survival of Biological Therapies in Patients with Moderate-to-Severe Psoriasis

Biological therapies (BTs) indicated for psoriasis are highly effective; however, not all patients obtain good results, and loss of effectiveness is the main reason for switching. Genetic factors may be involved. The objective of this study was to evaluate the influence of single-nucleotide polymorphisms (SNPs) on the drug survival of tumor necrosis factor inhibitors (anti-TNF) medications and ustekinumab (UTK) in patients diagnosed with moderate-to-severe psoriasis. We conducted an ambispective observational cohort study that included 379 lines of treatment with anti-TNF (n = 247) and UTK (132) in 206 white patients from southern Spain and Italy. The genotyping of the 29 functional SNPs was carried out using real-time polymerase chain reaction (PCR) with TaqMan probes. Drug survival was evaluated with Cox regression and Kaplan-Meier curves. The multivariate analysis showed that the HLA-C rs12191877-T (hazard ratio [HR] = 0.560; 95% CI = 0.40-0.78; p = 0.0006) and TNF-1031 (rs1799964-C) (HR = 0.707; 95% CI = 0.50-0.99; p = 0.048) polymorphisms are associated with anti-TNF drug survival, while TLR5 rs5744174-G (HR = 0.589; 95% CI = 0.37-0.92; p = 0.02), CD84 rs6427528-GG (HR = 0.557; 95% CI = 0.35-0.88; p = 0.013) and PDE3A rs11045392-T together with SLCO1C1 rs3794271-T (HR = 0.508; 95% CI = 0.32-0.79; p = 0.002) are related to UTK survival. The limitations are the sample size and the clustering of anti-TNF drugs; we used a homogeneous cohort of patients from 2 hospitals only. In conclusion, SNPs in the HLA-C, TNF, TLR5, CD84, PDE3A, and SLCO1C1 genes may be useful as biomarkers of drug survival of BTs indicated for psoriasis, making it possible to implement personalized medicine that will reduce financial healthcare costs, facilitate medical decision-making and improve patient quality of life. However, further pharmacogenetic studies need to be conducted to confirm these associations.

Towards Personalized Medicine in Psoriasis: Current Progress

Although innovative targeted therapies have positively revolutionized psoriasis treatment shifting treatment goals to complete or almost complete skin clearance, primary or secondary lack of efficacy is still possible. Hence, identifying robust biomarkers that reflect the various clinical psoriasis phenotypes would allow stratify patients in subgroups or endotypes, and tailor treatments according to the characteristics of each individual (precision medicine). To sum up the current progress in personalized medicine for psoriasis, we performed a review on the available evidence on biomarkers predictive of response to psoriasis treatments, with focus on phototherapy and systemic agents. Relevant literature published in English was searched for using the following databases from the last five years up to March 20, 2022: PubMed, Embase, Google Scholar, EBSCO, MEDLINE, and the Cochrane library. Currently, more evidence exists towards biologicals, as justified by the huge health care costs as compared to phototherapy or conventional systemic drugs. Among them, most of the studies focused on anti-TNF and IL12/23, with still few on IL17 (mainly secukinumab). The most discussed biomarker gene is the HLA-C*02:06 status that has been shown to be associated with psoriasis, and also differential response to biologicals. Although its positivity is associated with great response to MTX, debatable results were retrieved concerning both anti-TNF and IL12/23 while it seems not to affect secukinumab response. Personalized treatment in psoriasis would provide excellent outcome minimizing the risk of side effects. To date, although several candidates were proposed and assessed, the scarcity and heterogeneity of the results do not allow the identification of the gold-standard biomarker per each treatment. Anyway, the creation of a more comprehensive panel would be more reliable for the treatment decision process.

Identifying Novel Psoriatic Disease Drug Targets Using a Genetics-Based Priority Index Pipeline

BACKGROUND

Despite numerous genome-wide association studies conducted in psoriasis and psoriatic arthritis, only a small fraction of the identified genes has been therapeutically targeted.

OBJECTIVE

We sought to identify and analyze potential therapeutic targets for psoriasis and psoriatic arthritis (PsA) using the priority index (Pi), a genetics-dependent drug target prioritization approach.

METHODS

Significant genetic variants from GWAS for psoriasis, PsA, and combined psoriatic disease were annotated and run through the Pi pipeline. Potential drug targets were identified based on genomic predictors, annotation predictors, pathway enrichment, and pathway crosstalk.

RESULTS

Several gene targets were identified for psoriasis and PsA that demonstrated biological associations to their respective diseases. Some are currently being explored as potential therapeutic targets (i.e. ICAM1, NF-kB, REV3L, ADRA1B for psoriasis; CCL11 for PsA); others have not yet been investigated (i.e. LNPEP, LCE3 for psoriasis; UBLCP1 for PsA). Additionally, many nodal points of potential intervention were identified as promising therapeutic targets. Of these, some are currently being studied such as TYK2 for psoriasis, and others have yet to be explored (i.e. PPP2CA, YAP1, PI3K, AKT, FOXO1, RELA, CSF2, IFNGR1, IFNGR2 for psoriasis; GNAQ, PLCB1, GNAI2 for PsA).

CONCLUSION

Through Pi, we identified data-driven candidate therapeutic gene targets and pathways for psoriasis and PsA. Given the sparse PsA specific genetic studies and PsA specific drug targets, this analysis could prove to be particularly valuable in the pipeline for novel psoriatic therapies.

Influence of Genetic Polymorphisms on Response to Biologics in Moderate-to-Severe Psoriasis

Psoriasis is a chronic inflammatory skin pathology of autoimmune origin and unknown etiology. There are various therapies for treating it, including a wide range of biopharmaceuticals indicated in moderate-to-severe psoriasis. Depending on their therapeutic target, they are classified as tumor necrosis factor inhibitors (anti-TNF) or cytokine inhibitors (interleukin-12, 23, and 17 antagonists). Although they have proved effective and safe, in clinical practice, many patients show a short- and long-term suboptimal response and even varying degrees of toxicity. This variability in response may be influenced by genetic factors, such as polymorphisms in the genes involved in the pathological environment, metabolism or mechanism of action of the drug that could affect the effectiveness and toxicity of biological therapies. This review assesses pharmacogenetic studies of the impact of genetic factors on response to biopharmaceuticals and toxicity in patients diagnosed with moderate-to-severe psoriasis. The results suggest that polymorphisms detected in the HLA genes, in genes that encode cytokines (TNF, IL genes, TNFAIP3), transporters (PDE3A-SLCO1C1, SLC12A8), receptors (TNFRSF1B, CD84, FCGR2A and FCGR3A, IL17RA, IL23R, TLR genes, PGLYRP4) and associated proteins (TNFAIP3, LY96, TIRAP, FBXL19), as well as other genes implicated in the pathogenesis of psoriasis (CDKAL1, CARD14, PTTG1, MAP3K1, ZNF816A, GBP6, CTNNA2, HTR2A, CTLA4, TAP1) can be used in the future as predictive markers of treatment response and/or toxicity with biological therapies in patients diagnosed with moderate-to-severe psoriasis, tailoring treatment to the individual patient.

Apremilast Pharmacogenomics in Russian Patients with Moderate-to-Severe and Severe Psoriasis

One of the target drugs for plaque psoriasis treatment is apremilast, which is a selective phosphodiesterase 4 (PDE4) inhibitor. In this study, 34 moderate-to-severe and severe plaque psoriasis patients from Russia were treated with apremilast for 26 weeks. This allowed us to observe the effectiveness of splitting patient cohorts based on clinical outcomes, which were assessed using the Psoriasis Area Severity Index (PASI). In total, 14 patients (41%) indicated having an advanced outcome with delta PASI 75 after treatment; 20 patients indicated having moderate or no effects. Genome variability was investigated using the Illumina Infinium Global Screening Array. Genome-wide analysis revealed apremilast therapy clinical outcome associations at three compact genome regions with undefined functions situated on chromosomes 2, 4, and 5, as well as on a single single-nucleotide polymorphism (SNP) on chromosome 23. Pre-selected SNP sets were associated with psoriasis vulgaris analysis, which was used to identify four SNP-associated targeted therapy efficiencies: IL1β (rs1143633), IL4 (IL13) (rs20541), IL23R (rs2201841), and TNFα (rs1800629) genes. Moreover, we showed that the use of the global polygenic risk score allowed for the prediction of onset psoriasis in Russians. Therefore, these results can serve as a starting point for creating a predictive model of apremilast therapy response in the targeted therapy of patients with psoriasis vulgaris.

Predictors of drug survival of biologic therapies in psoriasis patients

INTRODUCTION

We aimed to investigate the clinical, immunological, and genetic factors affecting the response to anti-TNFα (tumor necrosis factor-α) and interleukin-12/23 therapies and drug survivals.

METHODS

A total of 180 patients were divided into two groups: 89 patients who used at least two biologic agents, with the initial biologic agent used less than 12 months (group A), and 91 biologic-naive patients who have been receiving a single biologic agent for more than 12 months (group B). ELISA (enzyme-linked immunosorbent assay) was used to analyze anti-drug antibodies (ADAs) in blood samples. Clinical data of the patients were retrospectively analyzed. HLA-SSO (sequence-specific oligonucleotide) Typing Kits were used for HLA-C typing. IBM SPSS v.21 was used for statistical analysis.Results: Infliximab had the longest drug survival as the first biologic agent in group A (p = .015). Etanercept had the lowest ADA count compared to the other anti-TNF agents (p = .001). HLA-Cw6 negativity, late-onset psoriasis, smoking and alcohol use were determined to be risk factors for treatment failure in group A. HLA-Cw6 was found to be associated with type I psoriasis (p = .000).

CONCLUSIONS

Although our study is retrospective of a relatively low number of patients, this is a preliminary study focusing on two different patient populations based on therapy response.

NFKBIZ and CW6 in Adalimumab Response Among Psoriasis Patients: Genetic Association and Alternative Transcript Analysis

BACKGROUND

Nuclear factor (NF)-κB is an essential mediator of the tumor necrosis factor (TNF) pathway, and has been implicated in psoriasis. NFKBIZ is a nuclear inhibitor of NF-κB with a prominent role in the pathogenesis of psoriasis. The genetic variation at the NFKBIZ gene has been associated with the risk of developing psoriasis, and could also contribute to defining the response to anti-TNF biological drugs.

OBJECTIVES

The objectives of this study were to determine the association of a common NFKBIZ insertion/deletion (indel) polymorphism (rs3217713) with the response to adalimumab and determine the differences in the relative expression of a NFKBIZ alternative transcript in patients with a positive versus negative response.

METHODS

We genotyped a common NFKBIZ polymorphism in 169 psoriasis patients treated with adalimumab classified as responders (n = 120) and non-responders (n = 49), according to whether they had a 75% reduction in the Psoriasis Area and Severity Index score (PASI75) at week 24. The Cw6 polymorphism was also determined and allele and genotype frequencies were compared between the groups. We also determined the rate of the expression of a NFKBIZ transcript lacking exon 10 relative to the normal transcript in 60 patients (27 non-responders). In addition, because the intron indel could affect RNA splicing, we investigated whether the level of the alternative transcript was related to the intronic genotype.

RESULTS

The NFKBIZ polymorphism was associated with adalimumab response, with carriers of the deletion allele significantly more frequent among responders (odds ratio = 2.76, 95% confidence interval 1.19-6.43; p = 0.015). The presence of the HLA-CW6 allele was also associated with a positive response in our cohort (p = 0.018). The alternative transcript was amplified in all the samples. We found higher but non-significant values of normal to alternative transcript in responders as well as in NFKBIZ insertion homozygotes.

CONCLUSION

Our study supported a significant effect of a common NFKBIZ polymorphism on the response to adalimumab. This result could help to optimize the prescription of this anti-TNF, but requires confirmation in other cohorts.

Pharmacogenetics and Pharmacogenomics in Moderate-to-Severe Psoriasis

Pharmacogenetics is the study of variations in DNA sequence related to drug response. Moreover, the evolution of biotechnology and the sequencing of human DNA have allowed the creation of pharmacogenomics, a branch of genetics that analyzes human genes, the RNAs and proteins encoded by them, and the inter-and intra-individual variations in expression and function in relation to drug response. Pharmacogenetics and pharmacogenomics are being used to search for biomarkers that can predict response to systemic treatments, including those for moderate-to-severe psoriasis. Psoriasis is a chronic inflammatory disease with an autoimmune contribution. Although its etiology remains unknown, genetic, epigenetic, and environmental factors play a role in its development. Diverse systemic and biologic therapies are used to treat moderate-to-severe psoriasis. However, these treatments are not curative, and patients exhibit a wide range of responses to them. Moderate-to-severe psoriasis is usually treated with systemic immunomodulators such as acitretin, ciclosporin, and methotrexate. Anti-tumor necrosis factor (TNF) drugs (adalimumab, etanercept, or infliximab) are the first-line treatment for patients resistant to conventional systemic therapies. Although these therapies are very efficient, around 30-50% of patients have inadequate response. Ustekinumab is a monoclonal antibody that targets interleukin (IL)-12 and IL-23 and is used for moderate-to-severe psoriasis. New drugs (apremilast, brodalumab, guselkumab, ixekizumab, and secukinumab) have recently been approved for psoriasis. However, response rates to systemic treatments for moderate-to-severe psoriasis range from 35 to 80%, so it is necessary to identify non-invasive biomarkers that could help predict treatment outcomes of these therapies and individualize care for patients with psoriasis. These biomarkers could improve patient quality of life and reduce health costs and potential side effects. Pharmacogenetic studies have identified potential biomarkers for response to biologic treatments for moderate-to-severe psoriasis. These biomarkers need to be validated in clinical trials involving large cohorts of patients before they can be translated to the clinic. We review pharmacogenetics and pharmacogenomics studies for the treatment of moderate-to-severe plaque psoriasis.

Limited clinical utility of HLA-Cw6 genotyping for outcome prediction in psoriasis patients under ustekinumab therapy: a monocentric, retrospective analysis

Purpose

Several studies have suggested that an HLA-Cw6+ allele can predict an improved outcome of treatment in psoriasis patients. The aim of the study was to assess whether the published association between HLA-Cw6 allele carriers and response to ustekinumab has the potential to impact treatment decisions.

Patients and methods

Differences in Psoriasis Activity and Severity Index 50, 75, and 90; Nail Psoriasis Severity Index; and Dermatology Life Quality Index at 16 weeks were evaluated between HLA-Cw6 allele carriers vs. non-carriers. Thirty patients with moderate-to-severe psoriasis under treatment with ustekinumab were included in our study.

Results

There was no difference between the two groups with respect to Psoriasis Activity and Severity Index 50, 75, and 90 or in terms of change in Nail Psoriasis Severity Index or Dermatology Life Quality Index.

Conclusion

In our retrospectively analyzed cohort, we could not detect the previously reported better response in HLA-Cw6+ vs. HLA-Cw6- patients.

HLA-Cw6 and psoriasis

Psoriasis is a multifactorial disease with a strong genetic background. HLA-Cw6 is one of the most strongly associated psoriasis susceptibility alleles. It is repeatedly observed to affect disease course, phenotypic features, severity, comorbidities and treatment outcomes. To the best of our knowledge, the roles of HLA-Cw6 in psoriasis have not yet been thoroughly reviewed. The worldwide frequency of the HLA-Cw6 allele varies greatly, with it being generally higher in white people than in Asians. The allele is associated with type I early-onset psoriasis. Stress, obesity and streptococcal pharyngitis are commonly observed in HLA-Cw6-positive patients. Phenotypically, HLA-Cw6 has been found to be associated with guttate psoriasis. In addition, patients carrying the allele are more likely to have arm, leg and trunk involvement, and the Koebner phenomenon. Patients with psoriatic arthritis with HLA-Cw6 more often have early onset and tend to show cutaneous symptoms before musculoskeletal symptoms. HLA-Cw6-positive patients have been shown in several studies to be more responsive to methotrexate and ustekinumab. However, this difference in ustekinumab efficacy was only moderate in a post-hoc analysis of a pivotal phase III study. HLA-Cw6 positivity also tends to be less frequent in high-need patients who fail conventional therapy. Small studies have also investigated the role of HLA-Cw6 in remission of psoriasis during pregnancy, and with the comorbidities of photosensitivity and atherosclerosis. Given the diverse nature of psoriasis pathogenesis, as well as the difference of HLA-Cw6 positivity in different ethnic groups, more studies are needed to confirm the role of HLA-Cw6 in psoriasis.

HLA-C*06:02 Does Not Predispose to Clinical Response Following Long-Term Adalimumab Treatment in Psoriatic Patients: A Retrospective Cohort Study

BACKGROUND

The genetic basis of predisposition to psoriasis is recognised; however, the response to psoriasis treatment in patients with different genetic predisposition is poorly understood.

OBJECTIVE

To analyse the presence of the HLA-C*06:02 polymorphism in psoriatic patients treated with adalimumab.

METHODS

Genomic DNA was extracted from whole blood of 122 patients with moderate-to-severe psoriasis treated with adalimumab for 3 years. Genotyping was performed using PCR. Disease severity was assessed by the Psoriasis Area and Severity Index (PASI) at day 0 and after 1, 3, 6, 12, 24 and 36 months. Logistic regression was used to evaluate the association between dependent variables (including HLA-C*06:02 status) and achievement of PASI 50, 75 and 90.

RESULTS

No difference was observed after adalimumab treatment between C*06:02 positive (HLA-C*06:02-POS) patients (n = 46) and C*06:02 negative (HLA-C*06:02-NEG) patients (n = 76) over the 3-year follow-up period in terms of PASI response or time-course when PASI response was achieved. However, a small, but non-statistically significant difference was noted between genotypes for PASI 50 at 1 month (HLA-C*06:02-NEG: 44.7% vs. HLA-C*06:02-POS: 56.5%) and at 3 months (HLA-C*06:02-NEG: 71.1% vs. HLA-C*06:02-POS: 80.4%). Simple logistic regression analysis did not reveal an association between independent variables (including C*06:02 status) and PASI response; however, multivariate regression revealed that gender (females better than males) was associated with achievement of PASI 50 at month 1 (OR 0.34, 95% CI 0.16-0.72, p = 0.005) and of PASI 75 at 3 months (OR 0.36, 95% CI 0.16-0.8, p = 0.012).

CONCLUSION

Adalimumab reduced long-term severity in patients with moderate-severe psoriasis, independent of their HLA-C*06:02 status.

A systematic review of pharmacogenetic studies on the response to biologics in patients with psoriasis

BACKGROUND

Biologics are indicated for treating moderate-to-severe psoriasis. As the number of biologics registered for the treatment of psoriasis increases, so does the need for biomarkers to guide personalized therapeutic decisions. Genetic variants might serve as predictors for treatment response, a field of research known as pharmacogenetics.

OBJECTIVES

To assess which genetic variants are associated with response to biologics in patients with psoriasis according to current literature.

METHODS

A systematic search was performed in Embase, MEDLINE, the Cochrane Library and Web of Science. In total, 26 papers were included in this systematic review; 24 original studies and two meta-analyses. Quality was assessed using a predesigned form and risk of bias was assessed using the Newcastle-Ottawa Scale.

RESULTS

The majority of studies reported a candidate gene approach, focusing on polymorphisms in genes related to the therapeutic target or to psoriasis susceptibility. Studied populations were small and results were divergent, especially for studies investigating tumour necrosis factor inhibitors. The evidence for the role of HLA-Cw6 in ustekinumab efficacy shows minimal heterogeneity, with a higher response rate among patients who were positive for HLA-Cw6 reported across three of five studies.

CONCLUSIONS

Pharmacogenetic studies in psoriasis have generated divergent results. Replication of findings in larger cohorts is required. Large-scale hypothesis-free searches for genetic biomarkers are needed to uncover the complete genetic background of outcomes for treatment with biologics.

Impact of pharmacogenomics upon the therapeutic response to etanercept in psoriasis and psoriatic arthritis

TNF-α inhibitors have demonstrated efficacy both as monotherapy and in combination with disease-modifying anti-rheumatic drugs (DMARDs) in the treatment of chronic inflammatory immune-mediated diseases. Etanercept is a decoy receptor" for TNF-α and it is composed of two p75 TNF-α receptors fused to human IgG1. Areas covered: We discuss the potential role of pharmacogenetics in predicting the response to etanercept in patients with Ps and PsA. Expert opinion: Pharmacogenetics represents the new frontier for the discovery of potential genetic markers of biological response to TNF-α inhibitors. Clinical studies showed that TNF-α -308 G/G, +489 GG and the +489 GA, TNF-α -857C (rs1799724), TNFRSF1B 676T (rs1061622), TNFAIP3 G SNP (rs610604), FcγRIIIA-V158F, HLA-C*06, IL-17 A (rs2275913 and rs10484879), IL-17F (rs763780) and IL17RA (rs4819554) SNPs favor the response to etanercept. However, most of these studies are often small and not sufficiently powered to detect an effect and markers tend to be more prognostic than predictive of therapeutic response. Furthermore, studies often examines only the effects of a single SNP, while it would be more useful to analyze more haplotypes in contemporary in the same patients. Appropriately designed clinical trials are needed before a pharmacogenetic approach may be applicable in daily clinical therapeutic practice.