Role of the HLA-C*06 allele in clinical response to ustekinumab: evidence from real life in a large cohort of European patients

The Role of Genetics on Psoriasis Susceptibility, Comorbidities, and Treatment Response

This review highlights advances made in psoriasis genetics, including findings from genome-wide association studies, exome-sequencing studies, and copy number variant studies. The impact of genetic variants on various comorbidities and therapeutic responses is discussed.

The association of age at psoriasis onset and HLA-C*06:02 with biologic survival in patients with moderate-to-severe psoriasis: a cohort study from the British Association of Dermatologists Biologics and Immunomodulators Register (BADBIR)

BACKGROUND

Few studies have used real-world data to investigate the association between biologic therapy survival and age at psoriasis onset or HLA-C*06:02 status in patients with moderate-to-severe psoriasis. The robustness of these studies is limited by small sample size, short follow-up and diverse safety and effectiveness measures.

OBJECTIVES

To describe biologic survival and explore whether the response to biologics is modified by age at psoriasis onset or HLA-C*06:02 status in patients with moderate-to-severe psoriasis.

METHODS

Data from patients in the UK and the Republic of Ireland registered in the British Association of Dermatologists Biologics and Immunomodulators Register (BADBIR) from 2007 to 2022 on a first course of adalimumab, etanercept, secukinumab or ustekinumab with at least 6 months' follow-up and a subset of BADBIR patients with available HLA-C*06:02 information registered to Biomarkers and Stratification To Optimise outcomes in Psoriasis (BSTOP) were analysed. Patients aged ≥ 50 years at treatment initiation were classified into early-onset psoriasis (EOP) (presenting in patients ≤ 40 years of age) and late-onset psoriasis (LOP) (presenting in patients > 40 years of age). BADBIR patients with available information in BSTOP were categorized as HLA-C*06:02- or HLA-C*06:02 + . Biologic survival was defined as treatment discontinuation associated with ineffectiveness or occurrence of adverse events (AEs). Adjusted survival function and hazard ratio (aHR) with 95% confidence interval (CI) were estimated using a flexible parametric model to compare discontinuing therapy between age at psoriasis onset and HLA-C*06:02 groups. Each model included exposure (biologics), effect modifier (age at onset or HLA-C*06:02 status), interaction terms and several baseline demographic, clinical and disease severity covariates.

RESULTS

Final analytical cohorts included 4250 patients in the age at psoriasis onset group [2929 EOP (69%) vs. 1321 LOP (31%)] and 3094 patients in the HLA-C*06:02 status group [1603 HLA-C*06:02+ (52%) vs. 1491 HLA-C*06:02- (48%)]. There was no significant difference between EOP and LOP in drug survival associated with ineffectiveness or AEs for any biologics. However, compared with patients who were HLA-C*06:02-, patients who were HLA-C*06:02 + were less likely to discontinue ustekinumab for reasons associated with ineffectiveness (aHR 0.56, 95% CI 0.42-0.75).

CONCLUSIONS

HLA-C*06:02, but not age at psoriasis onset, is a predictive biomarker for biologic survival in patients with psoriasis. Findings from this large cohort provide further, important information to aid clinicians using biologic therapies to manage patients with psoriasis.

Exploring the impact of pharmacogenetics on personalized medicine: A systematic review

INTRODUCTION

Pharmacogenetics evaluates how genetic variations influence drug responses. Nowadays, genetic tests have advanced, becoming more affordable, and its integration is supported by stronger clinical evidence. Guidelines such as those from CPIC (Clinical Pharmacogenetics Implementation Consortium) and resources like PharmGKB facilitate genotype-based prescribing; and organizations like the FDA promote genetic testing before initiating certain medications. Preventive pharmacogenetic panels seem promising, but further research on biomarkers and diverse populations is needed. The aim of this review is to analyze recent evidence on the genotype-drug response relationship to examine how the genetic profile of patients influences the clinical response to treatments, and analyze the areas of research that need further study to advance towards a genetic-based precision medicine.

MATERIALS AND METHODS

A systematic search was conducted on PubMed to identify articles investigating the genotype-drug response relationship. The search strategy included terms such as "pharmacogenetics", "personalized treatment", "precision medicine", "dose adjustment", "individualizing dosing", "clinical routine", and "clinical practice." Clinical trials, observational studies, and meta-analyses published in English or Spanish between 2013 and 2023 were included. The initial search resulted in a total of 136 articles for analysis.

RESULTS

49 articles were included for the final analysis following review by 2 investigators. A relationship between genetic polymorphisms and drug response or toxicity was found for drugs such as opioids, GLP-1 agonists, tacrolimus, oral anticoagulants, antineoplastics, atypical antipsychotics, efavirenz, clopidogrel, lamotrigine, anti-TNFα agents, voriconazole, antidepressants, or statins. However, for drugs like metformin, quetiapine, irinotecan, bisoprolol, and anti-VEGF agents, no statistically significant association between genotype and response was found.

CONCLUSION

The studies analyzed in this review suggest a strong correlation between genetic variability and individual drug responses, supporting the use of pharmacogenetics for treatment optimization. However, for certain drugs like metformin or quetiapine, the influence of genotype on their response remains unclear. More studies with larger sample sizes, greater ethnic diversity, and consideration of non-genetic factors are needed. The lack of standardization in analysis methods and accessibility to genetic testing are significant challenges in this field. As a conclusion, pharmacogenetics shows immense potential in personalized medicine, but further research is required.

Gene Ontology Analysis Highlights Biological Processes Influencing Responsiveness to Biological Therapy in Psoriasis

Psoriasis is a chronic, immune-mediated and inflammatory skin disease. Although various biological drugs are available for psoriasis treatment, some patients have poor responses or do not respond to treatment. The aim of the present study was to highlight the molecular mechanism of responsiveness to current biological drugs for psoriasis treatment. To this end, we reviewed previously published articles that reported genes associated with treatment response to biological drugs in psoriasis, and gene ontology analysis was subsequently performed using the Cytoscape platform. Herein, we revealed a statistically significant association between NF-kappaB signaling (p value = 3.37 × 10-9), regulation of granulocyte macrophage colony-stimulating factor production (p value = 6.20 × 10-6), glial cell proliferation (p value = 2.41 × 10-5) and treatment response in psoriatic patients. To the best of our knowledge, we are the first to directly associate glial cells with treatment response. Taken together, our study revealed gene ontology (GO) terms, some of which were previously shown to be implicated in the molecular pathway of psoriasis, as novel GO terms involved in responsiveness in psoriatic disease patients.

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.

Pharmacogenomics on the Treatment Response in Patients with Psoriasis: An Updated Review

The efficacy and the safety of psoriasis medications have been proved in trials, but unideal responses and side effects are noted in clinical practice. Genetic predisposition is known to contribute to the pathogenesis of psoriasis. Hence, pharmacogenomics gives the hint of predictive treatment response individually. This review highlights the current pharmacogenetic and pharmacogenomic studies of medical therapy in psoriasis. HLA-Cw*06 status remains the most promising predictive treatment response in certain drugs. Numerous genetic variants (such as ABC transporter, DNMT3b, MTHFR, ANKLE1, IL-12B, IL-23R, MALT1, CDKAL1, IL17RA, IL1B, LY96, TLR2, etc.) are also found to be associated with treatment response for methotrexate, cyclosporin, acitretin, anti-TNF, anti-IL-12/23, anti-IL-17, anti-PDE4 agents, and topical therapy. Due to the high throughput sequencing technologies and the dramatic increase in sequencing cost, pharmacogenomic tests prior to treatment by whole exome sequencing or whole genome sequencing may be applied in clinical in the future. Further investigations are necessary to manifest potential genetic markers for psoriasis treatments.

Blood Cell Biomarkers of Inflammation and Cytokine Levels as Predictors of Response to Biologics in Patients with Psoriasis

For people with psoriasis, biomarkers aiding in the personalization of treatment with biologics are needed. We examined the usefulness of several biomarkers of inflammation in this respect. The neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR), and the systemic immune-inflammation index (SII) were measured in patients with psoriasis initiating TNF-α inhibitors (n = 131), IL-17/IL-17R inhibitors (n = 65), or IL-23/IL-12/23 inhibitors (n = 50). The blood levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, interferon (IFN)-γ, IL-17A, IL-6, soluble IL-6 receptor (sIL-6R), and soluble IL-6 signal transducer (sIL-6ST) were measured in patients initiating adalimumab (n = 62) or IL-17/IL-17R inhibitors (n = 24). Treatment response was defined by a psoriasis area and severity index (PASI) ≤ 2 three months after treatment initiation. Responders to TNF-α inhibitors had a lower NLR at baseline than non-responders (median and interquartile range (IQR) 2.15 (1.67-2.86) vs. 2.54 (1.88-3.55); p = 0.04). Responders to treatment with adalimumab had lower IL-6 levels at baseline than non-responders (0.99 (0.42-1.4) vs. 1.62 (0.96-2.41) pg/mL; p = 0.02). For the majority of patients, the IL-17A, IL-1β, and IFN-γ levels were below quantification limits. NLR and IL-6 may serve as predictive biomarkers of treatment response to TNF-α inhibitor therapy in patients with psoriasis.

Real-world use of ustekinumab therapeutic drug monitoring in moderate to severe psoriasis

Introduction

There is growing evidence that therapeutic drug monitoring of biologic therapy is beneficial in psoriatic patients. With respect to ustekinumab, the available evidence has not shown any relationship yet. The objective of this study is to identify correlations among ustekinumab trough concentrations, anti-ustekinumab antibodies and clinical response in moderate-to-severe plaque psoriasis patients, in a real-world setting.

Methods

Observational prospective follow-up study in psoriatic patients treated with ustekinumab. Patients were classified in optimal (PASI ≤ 3) and suboptimal responders (PASI > 3). Mann-Whitney U test and Spearman's rank correlation coefficient were used. Receiver-operator characteristic curve analysis was performed to identify ustekinumab concentration cut-off to achieve optimal response. A p-value < 0.05 was considered statistically significant.

Results

A total of 59 patients were included. Forty-eight patients (81.4%) corresponded to optimal responders and 11 (18.6%) to suboptimal responders. There was significant difference to ustekinumab concentrations: 0.7 μg/mL (range <0.1-1.8) vs. 0.4 μg/mL (range <0.1-0.8) respectively (p = 0.007). Positive correlation between ustekinumab concentration and psoriasis area and severity index (PASI) value was detected (p = 0.009). A cut-off value of 0.6 μg/mL ustekinumab concentration was found to achieve clinical response. Anti-ustekinumab antibodies were detected in 2 (3.4%) samples, both suboptimal responders.

Conclusion

A positive correlation exits between ustekinumab concentration and clinical response (optimal response PASI values ≤ 3) in blood draws performed before drug administration. The measurement of anti-ustekinumab antibodies could be considered in treatment failure.

Biomarkers of systemic treatment response in people with psoriasis: a scoping review

BACKGROUND

Responses to the systemic treatments commonly used to treat psoriasis vary. Biomarkers that accurately predict effectiveness and safety would enable targeted treatment selection, improved patient outcomes and more cost-effective healthcare.

OBJECTIVES

To perform a scoping review to identify and catalogue candidate biomarkers of systemic treatment response in psoriasis for the translational research community.

METHODS

A systematic search of CENTRAL, Embase, LILACS and MEDLINE was performed for relevant articles published between 1990 and December 2021. Eligibility criteria were studies involving patients with psoriasis (any age, n ≥ 50) reporting biomarkers associated with systemic treatment response. The main outcomes were any measure of systemic treatment efficacy or safety. Data were extracted by one reviewer and checked by a second; studies meeting minimal quality criteria (use of methods to control for confounding) were formally assessed for bias. Candidate biomarkers were identified by an expert multistakeholder group using a majority voting consensus exercise and mapped to relevant cellular and molecular pathways.

RESULTS

Of 71 included studies (67 studying effectiveness outcomes and eight safety outcomes; four studied both), most reported genomic or proteomic biomarkers associated with response to biologics (48 studies). Methodological or reporting limitations frequently compromised the interpretation of findings, including inadequate control for key covariates, lack of adjustment for multiple testing, and selective outcome reporting. We identified candidate biomarkers of efficacy to tumour necrosis factor inhibitors [variation in CARD14, CDKAL1, IL1B, IL12B and IL17RA loci, and lipopolysaccharide-induced phosphorylation of nuclear factor (NF)-κB in type 2 dendritic cells] and ustekinumab (HLA-C*06:02 and variation in an IL1B locus). None were supported by sufficient evidence for clinical use without further validation studies. Candidate biomarkers were found to be involved in the immune cellular crosstalk implicated in psoriasis pathogenesis, most notably antigen presentation, T helper (Th)17 cell differentiation, positive regulation of NF-κB, and Th17 cell activation.

CONCLUSIONS

This comprehensive catalogue provides a key resource for researchers and reveals a diverse range of biomarker types and outcomes in the included studies. The candidate biomarkers identified require further evaluation in methodologically robust studies to establish potential clinical utility. Future studies should aim to address the common methodological limitations highlighted in this review to expedite discovery and validation of biomarkers for clinical use. What is already known about this topic? Responses to the systemic treatments commonly used to treat psoriasis vary. Biomarkers that accurately predict effectiveness and safety would enable targeted treatment selection, improved patient outcomes and more cost-effective healthcare. What does this study add? This review provides a comprehensive catalogue of investigated biomarkers of systemic treatment response in psoriasis. A diverse range of biomarker types and outcomes was found in the included studies, serving as a key resource for the translational research community.

Super-Responders in Moderate–Severe Psoriasis under Guselkumab Treatment: Myths, Realities and Future Perspectives

A fast skin clearance is the main goal to achieve in psoriasis treatment. Patients that present a fast and exceptional improvement with treatment are called super-responders (SR). There is no consensus on the definition of SR with respect to psoriasis. Included herein is a retrospective analysis of a multicenter, observational study of real clinical practices including patients with moderate-to-severe plaque PSO undergoing treatment with Guselkumab (GUS). This cross-sectional analysis includes information on patients between February 2019 to February 2022. A SR is a patient that achieved a PASI = 0 at weeks 12 and 24. Analyses have been performed “as observed” using GraphPad Prism version 8.3.0 for Windows (GraphPad Software, San Diego, CA, USA, At baseline, the PASI is significantly correlated with VAS_pruritus, BSA, and DLQI, while DLQI is significantly correlated with VAS_pruritus. Significant correlations increase in number and magnitude over the follow-up time. In relation to the univariate logistic models carried out, only three variables showed a significant association with the super-responder variable: depression, VAS_pruritus, and DLQI.SR patients, who show a faster evolution in PASI and BSA improvement than non-SRs. Based on the results obtained, it would be possible to also include DLQI and VAS_pruritus in the broader concept of the SR.

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.

Pharmacodynamics of Janus kinase inhibitors for the treatment of atopic dermatitis

INTRODUCTION

Atopic dermatitis (AD) is the most common inflammatory skin disorder. Despite the high disease burden, the therapeutic options are limited and their efficacy in controlling AD might be partially satisfactory.

AREAS COVERED

Most of the key mediators in AD pathogenesis act through the JAK/STAT signaling pathway, which represents a valid therapeutic target. The first generation of JAK inhibitors, namely tofacitinib and ruxolitinib, inhibit multiple JAKs, whereas newer JAK inhibitors show more selective inhibitory effects for specific JAKs. The aim of this review was to discuss the role of the JAK/STAT pathway in AD and its inhibition, with a special focus on pharmacodynamic properties. We checked the English-language literature, published in the last 15 years using PubMed, Google Scholar, and Scopus.

EXPERT OPINION

JAK inhibitors have different selectivity for various JAK molecules, which influences their pharmacodynamics, efficacy and safety profile. Since many key cytokines in AD signal through JAK1, and as the selective JAK1 inhibition may be effective, avoiding the concomitant inhibition of JAK2- and JAK3-dependent pathways could be associated with additional safety issues. Therefore, selective JAK1 inhibitors may represent promising therapeutic agents for AD, as they might prevent off-target effects of JAK inhibitors, especially related to the hematologic profile.

Genome-Wide Association Study of Ustekinumab Response in Psoriasis

Heterogeneous genetic and environmental factors contribute to the psoriasis phenotype, resulting in a wide range of patient response to targeted therapies. Here, we investigate genetic factors associated with response to the IL-12/23 inhibitor ustekinumab in psoriasis. To date, only HLA-C*06:02 has been consistently reported to associate with ustekinumab response in psoriasis. Genome-wide association testing was performed on the continuous outcome of percent change in Psoriasis Area Severity Index (PASI) at 12 weeks of ustekinumab therapy relative to baseline. A total of 439 European ancestry individuals with psoriasis were included [mean age, 46.6 years; 277 men (63.1%)]. 310 (70.6%) of the participants comprised the discovery cohort and the remaining 129 (29.4%) individuals comprised the validation cohort. Chromosome 4 variant rs35569429 was significantly associated with ustekinumab response at 12 weeks at a genome-wide significant level in the discovery cohort and replicated in the validation cohort. Of psoriasis subjects with at least one copy of the deletion allele of rs35569429, 44% achieved PASI75 (75% improvement in PASI from baseline) at week 12 of ustekinumab treatment, while for subjects without the deletion allele, 75% achieved PASI75 at week 12. We found that differences in treatment response increased when rs35569429 was considered alongside HLA-C*06:02. Psoriasis patients with the deletion allele of rs35569429 who were HLA-C*06:02 negative had a PASI75 response rate of 35% at week 12, while those without the deletion allele who were HLA-C*06:02 positive had a PASI75 response rate of 82% at week 12. Through GWAS, we identified a novel SNP that is potentially associated with response to ustekinumab in psoriasis.

Correlation of HLA-Cw6 Positivity with Clinical Characteristics and Treatment Efficacy in Korean Patients with Psoriasis

Background

Psoriasis is a multifactorial, chronic immunological disease, in which a specific allele HLA-Cw6 is associated with various clinical manifestations. However, information regarding this genetic factor in Korean patients with psoriasis remains limited.

Objective

We aimed to explore the differences in clinical patterns and treatment responsiveness, depending on the expression of HLA-Cw6, in Korean patients with psoriasis.

Methods

We divided patients into two groups, namely HLA-Cw6-positive and HLA-Cw6-negative, based on the HLA-Cw6 allelic analysis using the single specific primer-polymerase chain reaction method. All clinical information regarding these patients was collected in a retrospective manner. Next, we evaluated the levels of serum Th17-related cytokines in 34 patients diagnosed with psoriasis using a multiplex immunoassay. Finally, we performed immunohistochemical staining of interleukin (IL)-22 and IL-31, as these cytokines showed the maximum differential expression between the HLA-Cw6 positive and negative groups.

Results

HLA-Cw6 positive and negative groups comprised of 13 and 21 patients, respectively. HLA-Cw6-positive group had more chance of having metabolic comorbidities (76.9% for HLA-Cw6-positive group; 28.6% for HLA-Cw6-negative group; p=0.002). Also, HLA-Cw6-positive group showed significantly higher treatment response (38.5% in positive group showed Psoriasis Area and Severity Index 90% improvement compared to 4.8% in the negative group; p=0.012). However, all Th17-related cytokines were not significantly different across the two groups. Furthermore, IL-22 and IL-31 immunohistochemical staining did not correlate with the serum cytokines levels.

Conclusion

HLA-Cw6 types can be associated with disease severity, comorbidities, and treatment responsiveness in Korean patients with psoriasis.

Clinical Application of Pharmacogenetic Markers in the Treatment of Dermatologic Pathologies

Dermatologic pathologies are the fourth most common cause of non-fatal disease worldwide; however, they produce a psychosocial, economic, and occupational impact equal to or greater than other chronic conditions. The most prevalent are actinic keratosis, followed by basal-cell carcinoma, in a lesser proportion acne vulgaris, psoriasis, and hidradenitis suppurativa, among others, and more rarely dermatitis herpetiformis. To treat actinic keratosis and basal-cell carcinoma, 5-fluorouracil (5-FU) 0.5% is administered topically with good results, although in certain patients it produces severe toxicity. On the other hand, dapsone is a drug commonly used in inflammatory skin conditions such as dermatitis herpetiformis; however, it occasionally causes hemolytic anemia. Additionally, biologic drugs indicated for the treatment of moderate-to-severe psoriasis and hidradenitis suppurativa have proved to be effective and safe; nevertheless, a small percentage of patients do not respond to treatment with biologics in the long term or they are ineffective. This interindividual variability in response may be due to alterations in genes that encode proteins involved in the pathologic environment of the disease or the mechanism of action of the medication. Pharmacogenetics studies the relationship between genetic variations and drug response, which is useful for the early identification of non-responsive patients and those with a higher risk of developing toxicity upon treatment. This review describes the pharmacogenetic recommendations with the strongest evidence at present for the treatments used in dermatology, highlighting those included in clinical practice guides. Currently, we could only find pharmacogenetic clinical guidelines for 5-FU. However, the summary of product characteristics for dapsone contains a pharmacogenetic recommendation from the United States Food and Drug Administration. Finally, there is an enormous amount of information from pharmacogenetic studies in patients with dermatologic pathologies (mainly psoriasis) treated with biologic therapies, but they need to be validated in order to be included in clinical practice guides.

TaaI/Cdx-2 AA Variant of VDR Defines the Response to Phototherapy amongst Patients with Psoriasis

1,25-dihydroxyvitamin-D₃ plays a central role in the immune system via binding to the vitamin D receptor. VDR polymorphisms have been associated with multiple autoimmune disorders, including psoriasis. Until now, five VDR polymorphisms, FokI, ApaI, BsmI, TaqI and TaaI/Cdx2, have been studied in psoriasis, with contradicting results. Therefore, this study aimed to evaluate the association of VDR polymorphisms with susceptibility to psoriasis, effectiveness of NB-UVB phototherapy and concentration of proinflammatory cytokines and vitamin D amongst the Polish population. VDR polymorphisms were analyzed by PCR-RFLP or real-time PCR. We found that the frequency of the TaaI/Cdx-2 GG genotype was significantly higher in psoriasis patients and was associated with regulation of IL-17 and IL-23 concentration. Moreover, TaaI/Cdx-2 AA might have a significant effect on the response to phototherapy amongst patients with psoriasis. Our results suggest that VDR is a susceptibility factor for psoriasis development. Moreover, TaaI/Cdx-2 variants have a significant effect on the response to phototherapy amongst patients with psoriasis and regulation of inflammatory response via decrease of IL-17 and IL-23 level after UVB phototherapy in the Polish population. Results of our study provide some evidence in support of the hypothesis that the vitamin D signaling pathway may be of relevance for pathogenesis and treatment of psoriasis.

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.

HLA-Cw6 and other HLA-C alleles, as well as MICB-DT, DDX58, and TYK2 genetic variants associate with optimal response to anti-IL-17A treatment in patients with psoriasis

Objective: Our pharmacogenomic study evaluated the influence of the presence/absence of genetic variants of psoriasis-risk loci on the clinical response to secukinumab. Differences in the single-nucleotide polymorphism (SNP) pattern characterizing HLA-Cw6+ or HLA-Cw6- patient subpopulations, showing high or low responses to secukinumab, were also analyzed. Methods: 417 SNPs were analyzed by Next-Generation Sequencing technology, in a cohort of 62 psoriatic patients and undergone secukinumab treatment. Univariate regression analysis was employed to examine the association between SNP and clinical response to secukinumab. Multivariate analysis was also performed to assess multivariate differences in SNP pattern of HLA-Cw6+ or HLA-Cw6- patients showing high or low responses to secukinumab. Results: Eight SNPs in HLA-C and upstream region (rs13207315, rs6900444, rs12189871, rs12191877, rs4406273, and rs10484554), including HLA-Cw6 classical allele (rs1131118), and three in MICB-DT (rs9267325), DDX58 (rs34085293) and TYK2 (rs2304255) genes, associating with excellent response to secukinumab were identified. Importantly, rs34085293 or rs2304255 SNP status defined a subgroup of super-responder patients. We also found that HLA-Cw6+ and HLA-Cw6- patients carried out specific patterns of SNPs associating with different responses to secukinumab. Conclusion: Assessment of HLA-Cw6, together with other allelic variants of genes, could be helpful to define patients which better benefit from anti-IL-17 therapy. Abbreviations: PASI: Psoriasis Area and Severity Index; SNP: Single-Nucleotide Polymorphism Rs: Reference SNP; PASI75: 75% reduction in Psoriasis Area and Severity Index; PASI90: 90% reduction in Psoriasis Area and Severity Index; PASI100: 100% reduction in Psoriasis Area and Severity Index; NGS: Next-Generation Sequencing; OR: Odds Ratio; CAP: Canonical Analysis of Principal coordinates; BMI: Body Mass Index; LD: Linkage Disequilibrium.

The IL-17/IL-23 Axis and Its Genetic Contribution to Psoriatic Arthritis

Psoriatic arthritis (PsA) is a chronic inflammatory disease belonging to the family of spondyloarthropathies (SpA). PsA commonly aggravates psoriasis of the skin and frequently manifests as an oligoarthritis with axial skeletal involvement and extraarticular manifestations including dactylitis, enthesitis, and uveitis. The weight of genetic predisposition to psoriasis and PsA is illustrated by the concordance rates in monozygotic twins which clearly demonstrate that genomics is insufficient to induce the clinical phenotype. The association of PsA with several single nucleotide polymorphisms (SNPs) at the IL23R locus and the involvement of Th17 cells in the immunopathogenesis of PsA clearly put the IL-23/IL-17 axis in the spotlight. The IL-23 and IL-17 cytokines have a pivotal role in the chronic inflammation of the synovium in PsA and are also prominent in the skin lesions of those with PsA. In this review, we focus on the genetic association of the IL-23/IL-17 axis with PsA and the contribution of these master cytokines in the pathophysiology of the disease, highlighting the main cell types incriminated in PsA and their specific role in the peripheral blood, lesional skin and joints of patients. We then provide an overview of the approved biologic drugs targeting the IL-23/IL-17 axis and discuss the advantages of genetic stratification to enhance personalized therapies in PsA.

Pharmacogenetics Update on Biologic Therapy in Psoriasis

Background and objectives: Psoriasis is a chronic immune-mediated skin disease caused by several complex factors, both environmental and genetic, many of which are still not fully understood. Nowadays, several groups of biological drugs are being used for psoriasis treatment. Although these therapies are very effective, they show significant variability in efficacy among individuals. Therefore, there is a need for biomarkers to predict treatment outcomes in order to guide personalized therapeutic decisions. Pharmacogenetics is the study of variations in DNA sequences related to drug response. Materials and Methods: In this article, we review pharmacogenetics studies on the treatment of moderate-to-severe psoriasis focusing on anti-interleukin (IL) 12/23 (ustekinumab) and anti-IL17 drugs (secukinumab and ixekizumab), as well as recent studies concerning anti-TNF drugs. Results: Several polymorphisms have been studied over the years in reference to anti-TNF drugs; some of the most recent studies included the performance of a genome-wide association study (GWAS) and pharmacogenetics studies focused on the optimization of a treatment regimen. Various polymorphisms in different genes have been related to ustekinumab response; among them, the most commonly studied is the HLA-C*06:02 allele. Conclusions: Although not confirmed in some studies, most studies have shown that patients carrying this allele present a significantly higher response rate to ustekinumab. Some polymorphisms have been studied in patients treated with anti-IL17 drugs, mostly related to secukinumab; however, up to now, no association has been found between any of these polymorphisms and response. Nevertheless, further studies involving larger cohorts are needed in order to confirm these results before the implementation of this biomarker in clinical practice.

A review of secukinumab in psoriasis treatment

Psoriasis is a systemic immunologic disorder associated with decreased quality of life and numerous co-morbidities, including psoriatic arthritis and cardiovascular disease. Secukinumab, a fully human IgG1 monoclonal antibody, selectively binds IL-17A and is approved by the US FDA and European Medicines Agency for moderate-to-severe plaque psoriasis and psoriatic arthritis. This review examines the efficacy and safety of secukinumab for the treatment of psoriasis using the literature retrieved from the PubMed database. In clinical trials, treatment with secukinumab led to rapid and sustained improvement in Psoriasis Area and Severity Index (PASI) scores, with PASI 90 response rates up to 68.5% at 5 years. Long-term clinical trial and real-world data have established secukinumab as a safe and effective treatment for psoriasis.

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.

Clinical Consequences of Antibody Formation, Serum Concentrations, and HLA-Cw6 Status in Psoriasis Patients on Ustekinumab

BACKGROUND

Ustekinumab for the treatment of psoriasis is currently administered in a standard dosing regimen. However, some patients tend to benefit from alternative dosing regimens, a step toward personalized medicine.

METHODS

To investigate the role of ustekinumab serum concentrations, anti-ustekinumab antibodies [AUA] and HLA-Cw6 status as tools for optimizing ustekinumab treatment, a multicenter prospective cohort study was conducted at an academic hospital with affiliated nonacademic hospitals in Belgium (cohort 1) and 2 academic hospitals in the Netherlands (cohort 2 and 3). Patients with plaque-type psoriasis were eligible if treated with ustekinumab for ≥16 weeks. Serum samples and Psoriasis Area and Severity Index scores were obtained at baseline, week 16, 28, 40, 52, and/or ≥64 of ustekinumab treatment.

RESULTS

A total of 137 patients with 229 observations for serum concentrations and AUA and 61 observations for HLA-Cw6 status were included. Presence of AUA (prevalence of 8.7%) was significantly associated with a diminished clinical response (P = 0.032). The median ustekinumab trough concentration was 0.3 mcg/mL (<0.02-3.80). No differences in serum concentrations were observed between moderate to good responders and nonresponders (P = 0.948). Serum trough concentrations were not affected by methotrexate comedication. Prevalence of HLA-Cw6 positivity was 41% with no statistically significant difference in clinical response between HLA-Cw6-positive and HLA-Cw6-negative patients (P = 0.164).

CONCLUSIONS

The presence of AUA was associated with treatment failure in this patient population; measurement of AUA may therefore be a candidate marker for personalized pharmacotherapy. The clinical utility of ustekinumab serum trough concentrations or HLA-Cw6 status determination remains less clear. Further exploration on the potential of measuring ustekinumab serum concentrations and other biomarkers in predicting therapy outcomes should be encouraged.

Association of HLA-C*06:02 Status With Differential Response to Ustekinumab in Patients With Psoriasis: A Systematic Review and Meta-analysis

Importance

Previous research showed a differential response to ustekinumab therapy based on HLA-C*06:02 status in patients with psoriasis but consisted mostly of small (and sometimes inconclusive) cohort studies.

Objective

To assess whether HLA-C*06:02 status is associated with a differential response to ustekinumab therapy in patients with psoriasis through a systematic review and a meta-analysis of available data.

Data Sources

A comprehensive search was conducted using MEDLINE, Embase, the Cochrane Library, Web of Science, and gray literature sources. Databases were searched from January 1, 2000, to May 14, 2018. Search strategies included terms and synonyms for psoriasis, HLA-C, and ustekinumab. Languages were restricted to English, French, German, and Dutch.

Study Selection

Studies were included if they reported the association between HLA-C*06:02 status and 75% improvement in Psoriasis Area and Severity Index (PASI75) response to ustekinumab therapy in patients with plaque psoriasis after 6 and/or 3 months of treatment. Randomized clinical trials and observational studies were included. Screening and selection were performed independently by 2 reviewers.

Data Extraction and Synthesis

HLA-C*06:02 genotype status and PASI75 response rates were extracted by 2 reviewers. Data were pooled using random-effects models. Heterogeneity was assessed using the τ2 and I2 statistic. Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) and Meta-Analysis of Observational Studies in Epidemiology (MOOSE) reporting guidelines were followed.

Main Outcome and Measure

The primary outcome was the risk difference of achieving PASI75 after 6 months of ustekinumab therapy between HLA-C*06:02-positive and HLA-C*06:02-negative patients.

Results

A total of 8 studies were reviewed; 1048 patients were included for meta-analyses, and 937 patients were included for the primary analysis of PASI75 response after 6 months of treatment. Random-effects meta-analysis showed a risk difference of 0.24 (95% CI, 0.14-0.35; P < .001) in favor of HLA-C*06:02-positive patients. The median PASI75 response rate in the HLA-C*06:02-positive group was 92% (pooled, 89%; range, 62%-98%). For HLA-C*06:02-negative patients, the median response rate was 67% (pooled, 62%; range, 40%-84%). Substantial heterogeneity may have been present, with an I2 of 82%.

Conclusions and Relevance

The meta-analysis showed a differential response to ustekinumab therapy based on HLA-C*06:02 status in patients with psoriasis. Although HLA-C*06:02-positive patients had high PASI75 response rates after 6 months, the PASI75 response rate was also high in the HLA-C*06:02-negative group. There appears to be no rationale for excluding patients from ustekinumab treatment based on a negative HLA-C*06:02 status.

Response to IL-17A inhibitors secukinumab and ixekizumab cannot be explained by genetic variation in the protein-coding and untranslated regions of the IL-17A gene: results from a multicentre study of four European psoriasis cohorts

BACKGROUND

Genetic predictors for treatment response could optimize allocation of biological treatment in patients with psoriasis. There is minimal knowledge about pharmacogenetics of anti-IL-17 agents.

OBJECTIVES

To assess whether genetic variants in the protein-coding region or untranslated regions of the IL-17A gene are associated with response to IL-17A inhibitors in patients with psoriasis.

METHODS

This was a multicenter European cohort study investigating pharmacogenetics of IL-17A inhibitors in patients with psoriasis. Patients with plaque psoriasis treated with secukinumab or ixekizumab in daily practice were included. For all participants, the protein-coding region and untranslated regions of the IL-17A gene were analysed using Sanger sequencing. Identified genetic variants were tested for association with response to secukinumab/ixekizumab, measured as ∆PASI, after 12 weeks (primary outcome) and after 24 weeks (secondary outcome). Association was tested using a linear regression model with correction for baseline PASI as a fixed covariate and for biological naivety and body mass index as additional covariates.

RESULTS

In total, 134 patients treated with secukinumab or ixekizumab were included. Genotyping of the cohort identified genetic variants present in untranslated regions and intronic DNA, but not in the protein-coding region of the IL-17A gene. Five genetic variants in non-coding DNA with a known or suspected functional effect on IL-17A expression were selected for association analyses: rs2275913, rs8193037, rs3819025, rs7747909 and rs3748067. After 12 weeks, 62% of patients achieved PASI75 and 39% achieved PASI90. At week 24, PASI75 and PASI90 response rates were 72% and 62%, respectively. No associations were found between the five genetic variants and ∆PASI, PASI75 or PASI90 after 12 and 24 weeks of anti-IL-17A treatment.

CONCLUSIONS

Response to IL-17A inhibitors secukinumab and ixekizumab cannot be explained by genetic variation in the protein-coding and untranslated regions of the IL-17A gene. Pharmacogenetics of IL-17A inhibitors in the treatment of psoriasis requires further exploration.

Association between HLA-Cw6 allele expression and characteristics of Javanese ethnic psoriasis patients in Indonesia

BACKGROUND Psoriasis is an autoimmune disease with involvement of genetic and environmental factors. The HLA-Cw6 allele is the strongest genetic factor that correlates with earlier onset and more severe clinical manifestation of psoriasis. In Javanese ethnic, HLA-Cw6 allelic expression has not been identified, although increasing psoriasis patients were found in hospital dermatology departments. The study was aimed to determine the allelic expression of HLA-Cw6 based on the onset and severity of psoriasis in Javanese ethnic. METHODS A cross-sectional study was conducted from March to September 2018. Sixty psoriasis patients in the Margono Soekarjo Hospital and Banyumas Regional General Hospital were recruited consecutively. Psoriasis type, diagnosis, onset, and disease severity were assessed by dermatologists. HLA-Cw6 allelic expression was identified by DNA isolation, quantitative testing, and HLA-Cw6 genotyping. Fisher’s exact and chi-square tests were used to evaluate the association of HLA-Cw6 with age, clinical type, disease severity, onset, and gender. RESULTS The HLA-Cw6 allele positivity was identified at 297 base pairs (bp), while control showed at 618 bp bands. Among 60 subjects, 13 subjects (22%) showed HLACw6 positivity, and 47 subjects (78%) were HLA-Cw6 negative. HLA-Cw6 genotypes were similarly distributed concerning age, onset, gender, clinical type, and disease severity in psoriasis patients of Javanese ethnic (p > 0.05). CONCLUSIONS HLA-Cw6 expression type may not have influence to the characteristics of patients with psoriasis.

HLA-C: An Accomplice in Rheumatic Diseases

Human leukocyte antigen c (HLA-C) is a polymorphic membrane protein encoded by the HLA-C gene in the class I major histocompatibility complex. HLA-C plays an essential role in protection against cancer and viruses but has also been implicated in allograft rejection, preeclampsia, and autoimmune disease. This review summarizes reports and proposed mechanisms for the accessory role of HLA-C in rheumatic diseases. Historically, contributions of HLA-C to rheumatic diseases were eclipsed by the stronger association with HLA-DRB1 alleles containing the "shared epitope" with rheumatoid arthritis. Larger genetic association studies and more powerful analytical approaches have revealed independent associations of HLA-C with rheumatic disease-associated phenotypes, including development of anticitrullinated peptide antibodies. HLA-C functions by presenting antigens to T cells and by binding activatory and inhibitory receptors on natural killer (NK) cells, but the exact mechanisms by which the HLA-C locus contributes to autoimmunity are largely undefined. Studies have suggested that HLA-C and NK cell receptor polymorphisms may predict responsiveness to pharmacotherapy. Understanding the mechanisms of the role of HLA-C in rheumatic disease could uncover therapeutic targets or guide precision pharmacologic treatments.

Review article: the genetics of the human leucocyte antigen region in inflammatory bowel disease

BACKGROUND

The human leucocyte antigen (HLA) complex, located at chromosome 6p21.3 is a highly polymorphic region containing the classical class I and II HLA genes. The region is highly associated with inflammatory bowel disease (IBD), largely through genome-wide association studies (GWAS).

AIMS

To review the role of HLA in immune function, summarise data on risk/protective HLA genotypes for IBD, discuss the role of HLA in IBD pathogenesis, treatment and examine limitations that might be addressed by future research.

METHODS

An organised search strategy was used to collate articles describing HLA genes in IBD, including Crohn's disease and ulcerative colitis.

RESULTS

All classical HLA genes with variation (including HLA-A, B, C, DRB1, DQA1, DQB1, DPA1 and DPB1) harbour IBD-associated genotypes. The most implicated gene is HLA-DRB1, with HLA-DRB1*03:01 the most associated risk allele in both Crohn's disease and ulcerative colitis. Elucidating precise disease associations is challenging due to high linkage disequilibrium between HLA genotypes. The mechanisms by which risk alleles cause disease are multifactorial, with the best evidence indicating structural and electrostatic alteration impacting antigen binding and downstream signalling. Adverse medication events have been associated with HLA genotypes including with thiopurines (pancreatitis) and anti-TNF agents (antibody formation).

CONCLUSIONS

The HLA complex is associated with multiple risk/protective alleles for IBD. Future research utilising long-read technology, ascertainment of zygosity and integration in disease modelling will improve the functional understanding and clinical translation of genetic findings.

Severe acute toxoplasmosis infection following ustekinumab treatment in a patient with psoriasis vulgaris

A 26-year-old man undergoing therapy with 45 mg ustekinumab (Stelara) for chronic psoriasis vulgaris was referred by his general practitioner to an infectious diseases department for fatigue, fever, night sweating, generalised lymphadenomegaly and unexplained weight loss. Physical examination revealed bilateral occipital, cervical, axillary and inguinal lymphadenomegalies in addition to splenomegaly. Preliminary investigation revealed elevated Plasmodium lactate dehydrogenase and an inversion of the CD4/CD8 ratio. Whole-body spiral CT scanning with and without contrast showed splenomegaly and highlighted supradiaphragmatic and subdiaphragmatic lymphadenopathies. A complete Infectious Disease Test Panel revealed high levels of anti-Toxoplasma gondii antibodies. Immunoglobulin G avidity was negative. Peripheral blood lymphocyte phenotyping was performed to exclude underlying lymphatic neoplasia. The diagnosis of severe acute toxoplasmosis infection in the setting of immune response modifiers was made. Ustekinumab was suspended indefinitely and the patient underwent monthly serological tests to monitor the immune response until all symptoms resolved and the serological testing was negative for Toxoplasma.

Combining Understanding of Immunological Mechanisms and Genetic Variants Toward Development of Personalized Medicine for Psoriasis Patients

Psoriasis is multifactorial disease with complex genetic predisposition. Recent advances in genetics and genomics analyses have provided many insights into the relationship between specific genetic predisposition and the immunopathological mechanisms driving psoriasis manifestation. Novel approaches which utilize array-based genotyping technologies such as genome-wide association studies and bioinformatics tools for transcriptomics analysis have identified single nucleotide polymorphisms, genes and pathways that are associated with psoriasis. The discovery of these psoriasis-associated susceptibility loci, autoimmune targets and altered signaling pathways have provided opportunities to bridge the gap of knowledge from sequence to consequence, allowing new therapeutic strategies for the treatment of psoriasis to be developed. Here, we discuss recent advances in the field by highlighting how immune functions associated with psoriasis susceptibility loci may contribute to disease pathogenesis in different populations. Understanding the genetic variations in psoriasis and how these may influence the immunological pathways to cause disease will contribute to the efforts in developing novel and targeted personalized therapies for psoriasis patients.

Efficacy of tildrakizumab for moderate-to-severe plaque psoriasis: pooled analysis of three randomized controlled trials at weeks 12 and 28

BACKGROUND

Efficacy of tildrakizumab for plaque psoriasis was demonstrated in randomized, placebo-controlled trials.

OBJECTIVE

To consolidate tildrakizumab efficacy results by pooling data.

METHODS

Data (N = 2081) from tildrakizumab 100 mg, tildrakizumab 200 mg and placebo groups in three trials were pooled.

RESULTS

Proportions of Psoriasis Area and Severity Index (PASI) 75 responders at week 12 were better with tildrakizumab 100 mg (62.3%) and tildrakizumab 200 mg (64.8%) vs. placebo (5.6%; P < 0.0001) and for PASI 90, PASI 100 and Physician's Global Assessment (PGA) 'clear' or 'minimal' vs. placebo (P < 0.0001). Responses increased from weeks 12 to 28. Week 12 PASI and PGA responses to tildrakizumab vs. placebo were numerically greater in patients with lower vs. higher bodyweight and were better with tildrakizumab 200 mg than tildrakizumab 100 mg for patients with higher bodyweight. Week 12 PASI 75 responses vs. placebo with tildrakizumab 100 mg were similar between patients with (55.0%) or without (56.7%) prior biologics. PASI 90, PASI 100 and PGA responses were generally higher in patients without prior biologics. Week 8 PASI 50 response predicted PASI 90 response.

CONCLUSION

Pooled data confirmed the efficacy of tildrakizumab for moderate-to-severe plaque psoriasis.

Human leukocyte antigen and demographic characteristics in Chinese patients with active peripheral type psoriatic arthritis who had inadequate response to conventional disease-modifying antirheumatic drugs in a single dermatologic clinic

Background

Correlation between severity of psoriasis and psoriatic arthritis (PsA) is inconsistent. Also, human leukocyte antigen (HLA)-Cw6 was found to be underrepresented in severe psoriasis who failed conventional systemic therapies, but the effect of HLA polymorphism on PsA severity needs to be confirmed.

Objectives

To describe the severity of psoriasis, demographic features and HLA polymorphism among Chinese patients with active peripheral type PsA who had inadequate response to conventional disease-modifying antirheumatic drugs.

Methods

We included all patients with PsA who had at least 3 tender and swollen peripheral joints despite at least two conventional non-biologic treatments in our clinic. Demographic results were compared with global pivotal studies of biologics for PsA. HLA-Cw and HLA-DRB1 genotyping was also analyzed.

Results

We identified 60 patients who met our inclusion criteria. The male to female ratio was 1.31:1. The majority of patients presented with psoriasis first (81.7%). The mean interval between psoriasis and PsA was 7.2 ± 8.1 years (mean ± SD). The baseline number of tender and swollen joints was 14.9 ± 10.7 and 11.3 ±10.2, respectively. In total, 41.7% subjects had more than 3% body surface area involvement of psoriasis. Genotyping of HLA-Cw and HLA-DRB1 was performed in 47 subjects. HLA-Cw*0702 was the most frequent allele (29.8%), followed by HLA-Cw*01 (26.6%). The frequency of HLA-Cw*0602 allele was similar to normal population. The most frequent HLA-DRB1 allele was HLA-DRB1*04 (20.2%), followed by HLA-DRB1*08 (16.0%). No cases carrying HLA-DRB1*13 were detected.

Conclusions

Compared with Western population, our patients had less psoriasis and PsA burden. The frequencies of HLA-Cw*06, HLA-Cw*12, and HLA-DRB1*07 were not increased. In contrast, HLA-Cw*0702 and HLA-DRB1*08 allele frequencies were increased compared with psoriasis patients and normal population in Taiwan. Future studies are still needed to characterize the demographic and genetic features of high need PsA patients.

Treating a Multidrug-Resistant Psoriatic HLA-C*18:01 Allele Carrier with Combination Ustekinumab Apremilast Therapy

BACKGROUND

Nowadays, even though several biologic therapies are available to treat psoriasis, multidrug-resistant disease continues to be a therapeutic challenge. Combination therapy has therefore become increasingly important. In this context, apremilast, according to its safety profile, could easily be combined with biologics in patients with comorbidities and/or recalcitrant multidrug-resistant psoriasis.

OBJECTIVE

Our goal is to share experience from our institution in the observation of a patient with severe chronic plaque psoriasis that was unresponsive to all anti-tumor necrosis factor-α treatment and to an anti-interleukin (IL)-17A drug and only partially responsive to ustekinumab, even in combination with apremilast. The patient carried a rare allele infrequently found in Caucasian people: human leukocyte antigen (HLA)-C*18:01. This allele has been found to be positively associated with psoriasis in Brazilian patients.

METHODS

The patient was typed for the HLA-C locus at high resolution via polymerase chain reaction sequence-specific oligonucleotide probes (PCR-SSOP) using a commercial kit (LAB^®Type, One Lambda Inc., Canoga Park, CA, USA).

RESULTS

Our patient, previously described as having multidrug-resistant psoriasis, commenced ustekinumab and apremilast combination therapy. After 12 weeks, the Psoriasis Area Severity Index score had worsened, and we suspended combination therapy because the patient reported an absence of any benefit and was experiencing side effects from the induction therapy with apremilast.

CONCLUSIONS

Expanding on the previously reported experience with this patient, we conclude that HLA-C*18:01 probably indicates a severe, recalcitrant, multidrug-resistant psoriasis phenotype for which proper therapy remains to be identified.

A safety evaluation of guselkumab for the treatment of psoriasis

INTRODUCTION

Guselkumab is a fully human monoclonal IgG1λ antibody for the treatment of plaque psoriasis that inhibits interleukin (IL)-23p19 subunit, reducing the proliferation of type 17 helper T (Th-17) cells and thus production of Th-17-derived pro-inflammatory cytokines, especially IL-17 and IL-22. Areas covered: In the following article, the mechanism of action and mainly the efficacy and safety profile of guselkumab available from results of trials will be discussed. We summarized these data after a literature review including PubMed search, relating proceedings and abstracts from relevant international conferences, assessment reports from European and United States regulatory agencies and treatment guidelines up to April 2018. Expert opinion: The central role of IL-23 in psoriasis pathogenesis is supported by genetic links of IL-23 and IL-23R alleles to psoriasis susceptibility; early clinical trials have demonstrated that sufficient inhibition of IL-23p19 results in rapid resolution of the disease. Targeting IL-23, may be responsible for the high efficacy and durable responses of guselkumab, avoiding some adverse effects of IL-17A blockade, like mucocutaneous candida infections or triggering/worsening of inflammatory bowel disease, experienced with agents acting selectively against this molecule and that seem to be class related.

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.

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.

Treatment Approaches to Moderate to Severe Psoriasis

Psoriasis is a common disease, which has a considerable impact on patients and the health care system. Treatment approaches to the disease may be various because some issues are not definitely addressed. Moreover, the therapeutic paradigms are continuously changing because of the recent approval of new treatments for psoriasis such as interleukin (IL)-17 inhibitors and apremilast. In this review, the factors influencing psoriasis severity, the indications for systemic treatments, the overall parameters to be considered in the treatment choice, life style interventions, and the recommendations for the use, screening, and monitoring of systemic therapies available including acitretin, cyclosporine, methotrexate, apremilast, adalimumab, etanercept, infliximab, secukinumab, ixekizumab, and ustekinumab are discussed. Finally, treatment approaches in special patient populations including children, the elderly, pregnant women, patients with a history of neoplasm, and candidates for surgical procedures are reported.