Pharmacogenetic biomarkers for secukinumab response in psoriasis patients in real-life clinical practice.

BACKGROUND: Prediction of the response to a biological treatment in psoriasis patients would allow efficient treatment allocation. OBJECTIVE: To identify polymorphisms associated with secukinumab response in psoriasis patients in a daily practice setting. METHODS: We studied 180 SNPs in patients with moderate-to-severe plaque psoriasis recruited from 15 Spanish hospitals. Treatment effectiveness was evaluated by absolute PASI ≤3 and ≤1 at 6 and 12 months. Individuals were genotyped using a custom Taqman array. Multiple logistic regression models were generated. Sensitivity, specificity and area under the curve (AUC) were analysed. RESULTS: A total of 173 patients were studied at 6 months, (67% achieved absolute PASI ≤ 3 and 65% PASI ≤ 1) and 162 at 12 months (75% achieved absolute PASI ≤ 3 and 64% PASI ≤ 1). Multivariable analysis showed the association of different sets of SNPs with the response to secukinumab. The model of absolute PASI≤3 at 6 months showed best values of sensitivity and specificity. Four SNPs were associated with the capability of achieving absolute PASI ≤ 3 at 6 months. rs1801274 (FCGR2A), rs2431697 (miR-146a) and rs10484554 (HLCw6) were identified as risk factors for failure to achieve absolute PASI≤3, while rs1051738 (PDE4A) was protective. AUC including these genotypes, weight of patients and history of biological therapy was 0.88 (95% CI 0.83-0.94), with a sensitivity of 48.6% and specificity of 95.7% to discriminate between both phenotypes. CONCLUSION: We have identified a series of polymorphisms associated with the response to secukinumab capable of predicting the potential response/non-response to this drug in patients with plaque psoriasis.

New polymorphisms associated with response to anti-TNF drugs in patients with moderate-to-severe plaque psoriasis.

Anti-tumor necrosis factor (anti-TNF) drugs are effective against psoriasis, although 20-30% of patients are nonresponders. Few pharmacogenomic studies have been performed to predict the response to anti-TNF drugs in psoriasis. We studied 173 polymorphisms to establish an association with the response to anti-TNF drugs in patients with moderate-to-severe plaque psoriasis (N=144). We evaluated the response using PASI75 at 3, 6 and 12 months. The results of the multivariate analysis showed an association between polymorphisms in PGLYR4, ZNF816A, CTNNA2, IL12B, MAP3K1 and HLA-C genes and the response at 3 months. Besides, the results for polymorphisms in IL12B and MAP3K1 were replicated at 6 months. We also obtained significant results for IL12B polymorphism at 1 year. Moreover, polymorphisms in FCGR2A, HTR2A and CDKAL1 were significant at 6 months. This is the first study to show an association with these polymorphisms. However, these biomarkers should be validated in large-scale studies before implementation in clinical practice.

IL17RA gene variants and anti-TNF response among psoriasis patients.

Polymorphisms at genes encoding proteins involved in the pathogenesis of psoriasis (Psor) or in the mechanism of action of biological drugs could influence the treatment response. Because the interleukin (IL)-17 family has a central role in the pathogenesis of Psor, we hypothesized that IL17RA variants could influence the response to anti-TNF drugs among Psor patients. To address this issue we performed a cross-sectional study of Psor patients who received the biological treatments for the first time, with a follow-up of at least 6 months. All of the patients were Caucasian, older than 18 years old, with chronic plaque Psor, and had completed at least 24 weeks of anti-TNF therapy (adalimumab, etanercept or infliximab). The treatment response to anti-TNF agents was evaluated according to the achievement of PASI50 and PASI75 at weeks 12 and 24. Those who achieved PASI75 at week 24 were considered good responders. All patients were genotyped for the selected single-nucleotide polymorphisms (SNPs) at IL17RA gene. A total of 238 patients were included (57% male, mean age 46 years). One hundred and five patients received adalimumab, 91 patients etanercept and 42 infliximab. The rs4819554 promoter SNP allele A was significantly more common among responders at weeks 12 (P=0.01) and 24 (P=0.04). We found a higher frequency of AA versus AG+GG among responders, but the difference was only significant at week 12 (P=0.03, odd ratio=1.86, 95% confidence of interval=1.05-3.27). Thus, in the study population, the SNP rs4819554 in the promoter region of IL17RA significantly influences the response to anti-TNF drugs at week 12.

Paradoxical psoriasiform reactions to anti-TNFα drugs are associated with genetic polymorphisms in patients with psoriasis.

Paradoxical psoriasiform reactions to anti-tumor necrosis factor α (TNFα) agents have been described. We aimed to study the association between these reactions and polymorphisms in genes previously associated with psoriasis or other autoimmune diseases. A total of 161 patients with plaque-type psoriasis treated with anti-TNFα drugs were genotyped for 173 single-nucleotide polymorphisms (SNPs) using the Illumina Veracode genotyping platform. Among the 161 patients, 25 patients developed a paradoxical psoriasiform reaction consisting of a change in morphology, mostly to guttate psoriasis (88%). These lesions developed 9.20±13.52 months after initiating treatment, mainly with etanercept (72%). Psoriasis type and a Psoriasis Area and Severity Index (PASI) 75 response to treatment were not associated with lesions. Multivariate logistic regression revealed that five SNPs (rs11209026 in IL23R, rs10782001 in FBXL19, rs3087243 in CTLA4, rs651630 in SLC12A8 and rs1800453 in TAP1) were associated with paradoxical reactions. This is the first study to show an association between genetic polymorphisms and paradoxical reactions in patients with psoriasis treated with anti-TNFα drugs.The Pharmacogenomics Journal advance online publication, 21 July 2015; doi:10.1038/tpj.2015.53.

Effect of Chondroitin Sulphate on Pro-Inflammatory Mediators and Disease Activity in Patients with Inflammatory Bowel Disease.

BACKGROUND/AIMS: To evaluate the incidence rate of relapse in patients with inflammatory bowel disease (IBD) undergoing chondroitin sulphate (CS) treatment and its effect on the concentrations of several pro-inflammatory proteins. METHODS: Prospective, observational, 12-month follow-up study in patients with IBD in remission, starting CS (Condrosan®, Bioiberica S.A.) treatment for osteoarthritis (OA). Crohn's Disease Activity Index and modified Truelove-Witts severity index were calculated for Crohn's disease and ulcerative colitis (UC) respectively. Levels of vascular endothelial growth factor (VEGFA), -C, fibroblast growth factor 2, hepatocyte growth factor, angiopoietin (Ang)-1, Ang-2, transforming growth factor beta, tumour necrosis factor alpha, interleukin (IL)-1ß, IL-6, IL-12, IL-17, IL-23, intracellular adhesion molecule-1, vascular adhesion molecule-1, matrix metalloproteinase-3 and PGE2 were quantified by ELISA. OA joint pain was evaluated using a visual analogue scale. RESULTS: A total of 37 patients (19 UC and 18 Crohn's disease) were included. The mean values for OA joint pain decreased after 12 months from 5.9 ± 2.8 to 3.0 ± 2.3 (p < 0.05). Only 1 patient (with UC) flared during follow-up. The incidence rate of relapse was 3.4% per patient-year of follow-up. Mean serum VEGFA levels increased between baseline (492 pg/ml) and 12-month treatment (799 pg/ml; p < 0.05). CONCLUSION: The incidence of IBD relapse in patients under CS treatment was lower than that generally reported. This treatment might modulate VEGFA. CS decreases OA-related pain in patients with IBD.

Gene polymorphisms that can predict response to anti-TNF therapy in patients with psoriasis and related autoimmune diseases.

Psoriasis (Ps) is a chronic inflammatory disease with an important genetic component. It shares pathophysiological mechanisms with other autoimmune diseases such as psoriatic arthritis (PsA), rheumatoid arthritis (RA) and Crohn's disease (CD). These conditions can be treated using biological drugs such as infliximab, adalimumab and etanercept, which selectively block the proinflammatory cytokine tumor necrosis factor (TNF)-α. Although these agents have greatly improved the prognosis of Ps, PsA, RA and CD, they do not cure the disease and are expensive; in addition, significant proportions of patients do not respond or develop serious adverse effects. Therefore, it is important to investigate biomarkers, such as gene polymorphisms, that can predict which patients will respond best to a specific drug. Some polymorphisms in genes TNF, TNF receptor superfamily 1B (TNFR1B) and TNFα-induced protein 3 gene (TNFAIP3) have been associated with response to anti-TNF therapy in patients with Ps. The present article reviews other polymorphisms that could also play a role in prediction of response to these treatments.

Use of pharmacogenetics in bioequivalence studies to reduce sample size: an example with mirtazapine and CYP2D6.

In bioequivalence studies, intra-individual variability (CV(w)) is critical in determining sample size. In particular, highly variable drugs may require enrollment of a greater number of subjects. We hypothesize that a strategy to reduce pharmacokinetic CV(w), and hence sample size and costs, would be to include subjects with decreased metabolic enzyme capacity for the drug under study. Therefore, two mirtazapine studies, two-way, two-period crossover design (n=68) were re-analysed to calculate the total CV(w) and the CV(w)s in three different CYP2D6 genotype groups (0, 1 and ≥ 2 active genes). The results showed that a 29.2 or 15.3% sample size reduction would have been possible if the recruitment had been of individuals carrying just 0 or 0 plus 1 CYP2D6 active genes, due to the lower CV(w). This suggests that there may be a role for pharmacogenetics in the design of bioequivalence studies to reduce sample size and costs, thus introducing a new paradigm for the biopharmaceutical evaluation of drug products.

Association of common genetic variants with risperidone adverse events in a Spanish schizophrenic population.

Risperidone non-compliance is often high due to undesirable side effects, whose development is in part genetically determined. Studies with genetic variants involved in the pharmacokinetics and pharmacodynamics of risperidone have yielded inconsistent results. Thus, the aim of this study was to investigate the putative association of genetic markers with the occurrence of four frequently observed adverse events secondary to risperidone treatment: sleepiness, weight gain, extrapyramidal symptoms and sexual adverse events. A series of 111 schizophrenia inpatients were genotyped for genetic variants previously associated with or potentially involved in risperidone response. Presence of adverse events was the main variable and potential confounding factors were considered. Allele 16Gly of ADRB2 was significantly associated with a higher risk of sexual adverse events. There were other non-significant trends for DRD3 9Gly and SLC6A4 S alleles. Our results, although preliminary, provide new candidate variants of potential use in risperidone safety prediction.

The relationship between tumour necrosis factor (TNF)-α promoter and IL12B/IL-23R genes polymorphisms and the efficacy of anti-TNF-α therapy in psoriasis: a case-control study.

BACKGROUND: Antitumour necrosis factor (anti-TNF)-α agents can be used successfully to treat patients with psoriasis and other inflammatory diseases. However, very few studies have examined the relationship between TNF-α polymorphisms and the response to anti-TNF-α agents. OBJECTIVES: To study the association of single nucleotide polymorphisms (SNPs) of the TNF-α promoter and IL12B/IL23R genes with the response to anti-TNF-α in patients with psoriasis. METHODS: SNPs for the TNF-α promoter and IL12B/IL23R genes, and the presence of the HLA-Cw6 haplotype were genotyped for 109 patients. We studied the association between these SNPs and the efficacy of treatment at 3 and 6 months [Psoriasis Area and Severity Index (PASI) and body surface area (BSA)]. RESULTS: Patients with the TNF-α-238GG genotype more frequently achieved a PASI75 at 6 months (82·5% vs. 58·8%, P = 0·049). At 6 months, patients with the TNF-α-857CT/TT genotypes showed greater improvements in PASI score and BSA (83·1% vs. 92·7%, P = 0·004; 82·7% vs. 92·6%, P = 0·009) and more frequently achieved PASI75 (71·4% vs. 96·3%, P = 0·006). More patients with the TNF-α-1031TT genotype achieved PASI75 at 3 months (90·8 vs. 75·7, P = 0·047) and 6 months (85·5% vs. 65·7%, P = 0·038) and demonstrated superior improvements in PASI at 6 months (89·9% vs. 78·7%, P = 0·041). Patients with the IL23R-GG genotype (rs11209026) achieved PASI90 at 6 months more frequently (66·3% vs. 0, P = 0·006) and the improvement of the PASI score was also greater (86·8% vs. 67·8%, P = 0·013). Patients with the HLA-Cw6 haplotype showed poorer response than those without this haplotype. CONCLUSION: This study identified a relationship between certain TNF-α and IL12B/IL23R polymorphisms and the short-term response to anti-TNF-α drugs. If these results are confirmed, this information will allow for stratified consent with more accurate prediction of response/personalized choice of treatment hierarchy for the patient.

[Study of genetic polymorphisms in the tumor necrosis factor α promoter region in Spanish patients with psoriasis]. / Estudio de los polimorfismos genéticos de la región promotora del TNF-α en pacientes españoles afectos de psoriasis.

BACKGROUND: Several studies have reported an association between tumor necrosis factor α (TNF-α) polymorphisms and inflammatory diseases such as psoriasis vulgaris and psoriatic arthritis, although the results vary according to the population studied. No studies have been performed in the Spanish population. OBJECTIVE: To analyze the polymorphisms of the promoter region of the TNF-α gene in patients with moderate to severe psorasis and to identify potential differences in genotype compared to a group of healthy volunteers. MATERIAL AND METHODS: Eighty-nine patients with moderate to severe psoriasis and 76 healthy controls with no personal or family history of psoriasis were selected. Polymorphisms of the TNF-α promoter region of both groups were genotyped. RESULTS: We observed a higher prevalence of the genotype with both wild-type alleles at positions -238 (GG genotype, 86.5% vs 70.4%, respectively) and -1031 (TT genotype, 80.2% vs 45.8%, respectively) in patients compared to the healthy control group. The differences at positions -308 and -857 were not significant. CONCLUSION: There are differences in polymorphisms at positions -238 and -1031 in patients with moderate to severe psoriasis compared to healthy volunteers. This observation provides further support for the importance of the part that TNF-α plays in the pathophysiology of this disease.

Consensus of experts from the Spanish Pharmacogenetics and Pharmacogenomics Society and the Spanish Society of Medical Oncology for the genotyping of DPYD in cancer patients who are candidates for treatment with fluoropyrimidines.

5-Fluorouracil (5-FU) and oral fluoropyrimidines, such as capecitabine, are widely used in the treatment of cancer, especially gastrointestinal tumors and breast cancer, but their administration can produce serious and even lethal toxicity. This toxicity is often related to the partial or complete deficiency of the dihydropyrimidine dehydrogenase (DPD) enzyme, which causes a reduction in clearance and a longer half-life of 5-FU. It is advisable to determine if a DPD deficiency exists before administering these drugs by genotyping DPYD gene polymorphisms. The objective of this consensus of experts, in which representatives from the Spanish Pharmacogenetics and Pharmacogenomics Society and the Spanish Society of Medical Oncology participated, is to establish clear recommendations for the implementation of genotype and/or phenotype testing for DPD deficiency in patients who are candidates to receive fluoropyrimidines. The genotyping of DPYD previous to treatment classifies individuals as normal, intermediate, or poor metabolizers. Normal metabolizers do not require changes in the initial dose, intermediate metabolizers should start treatment with fluoropyrimidines at doses reduced to 50%, and poor metabolizers are contraindicated for fluoropyrimidines.

Epigenetics in Non-tumor Immune-Mediated Skin Diseases.

Epigenetics is the study of the mechanisms that regulate gene expression without modifying DNA sequences. Knowledge of and evidence about how epigenetics plays a causative role in the pathogenesis of many skin diseases is increasing. Since the epigenetic changes present in tumor diseases have been thoroughly reviewed, we believe that knowledge of the new epigenetic findings in non-tumor immune-mediated dermatological diseases should be of interest to the general dermatologist. Hence, the purpose of this review is to summarize the recent literature on epigenetics in most non-tumor dermatological pathologies, focusing on psoriasis. Hyper- and hypomethylation of DNA methyltransferases and methyl-DNA binding domain proteins are the most common and studied methylation mechanisms. The acetylation and methylation of histones H3 and H4 are the most frequent and well-characterized histone modifications and may be associated with disease severity parameters and serve as therapeutic response markers. Many specific microRNAs dysregulated in non-tumor dermatological disease have been reviewed. Deepening the study of how epigenetic mechanisms influence non-tumor immune-mediated dermatological diseases might help us better understand the role of interactions between the environment and the genome in the physiopathogenesis of these diseases.

Novel antimigraineur dotarizine releases Ca2+ from caffeine-sensitive Ca2+ stores of chromaffin cells.

1. The novel antimigraineur, dotarizine (30 microM), increased cytosolic Ca2+ concentration, [Ca2+]c, in fura-2-loaded bovine adrenal chromaffin cells. This increase was transient, reached a peak in about 2 - 5 min (0.53+/-0.07 microM; n=19) and then declined to basal levels over a further 5 min period. 2. This transient rise of [Ca2+]c was mimicked by 1 microM thapsigargin and by 30 microM cyclopiazonic acid (CPA), but not by 30 microM flunarizine. Both thapsigargin and CPA occluded the effects of dotarizine and vice versa. 3. All three compounds suppressed the transient [Ca2+]c rises induced by caffeine (10 mM, 10 s); blockade induced by thapsigargin was irreversible and that induced by CPA and dotarizine was reversible. 4. Of the three compounds, only dotarizine blocked reversibly the [Ca2+]c spikes induced by short pulses of high K+ (70 mM, 5 s), suggesting that dotarizine blocks voltage-dependent Ca2+ channels but CPA and thapsigargin do not. 5. Dotarizine caused a gradual and reversible depletion of endoplasmic reticulum (ER) Ca2+ in chromaffin cells transfected with ER-targeted aequorin. CPA had a similar effect. 6. These data show that dotarizine shares with thapsigargin and CPA the ability to deplete Ca2+ in the ER; this novel action of dotarizine could be relevant to its prophylactic effects in migraine. Unlike thapsigargin and CPA, however, dotarizine additionally and reversibly blocks Ca2+ entry through voltage-dependent Ca2+ channels.

Evaluation of sex differences in the pharmacokinetics of ranitidine in humans.

A bioequivalence study of two oral formulations of 300 mg ranitidine was carried out in 16 healthy volunteers (8 men and 8 women), and the pharmacokinetics in both sexes were compared. There was bioequivalence of both formulations. The terminal half-life of ranitidine was 7% shorter and the oral apparent clearance 10.5% higher in women (1.44 L/h/kg) than in men (1.29 L/h/kg), although this difference did not reach statistical significance. No differences were observed in maximum concentration (Cmax) or the time of its occurrence (tmax). Sex, age, and weight did not correlate significantly with oral clearance. These results suggest that there are no sex differences in the pharmacokinetics of ranitidine, or that any differences would not be of clinical relevance. It also should be emphasized that bioequivalence trials also can be used to study other pharmacokinetic or pharmacodynamic characteristics of drugs without damaging the main endpoint of the study.

Effects of dotarizine and flunarizine on chromaffin cell viability and cytosolic Ca2+.

Dotarizine (a novel piperazine derivative with antimigraine properties) and flunarizine (a Ca2+ channel antagonist) were compared concerning: first, their ability to cause chromaffin cell damage in vitro; second, the possible correlation of their octanol/water partition coefficients and those of another 28 compounds (i.e., Ca2+ channel antagonists, blockers of histamine H1 receptors, antimycotics, beta-adrenoceptor antagonists, neuroleptics), with their ability to cause cell damage; third, their capacity to protect the cells against the damaging effects of veratridine; and fourth, their capabilities to enhance the basal cytosolic Ca2+ concentration in fura-2-loaded single chromaffin cells, or to modify the pattern of [Ca2+]i oscillations elicited by veratridine. After 24-h exposure to 1-30 microM dotarizine, the viability of bovine adrenal chromaffin cells (measured under phase contrast or as lactate dehydrogenase, released into the medium) was similar to that of control, untreated cells; at 100 microM, 80% lactate dehydrogenase release was produced. At 1-3 microM flunarizine caused no cell damage; however 10 microM caused 20% lactate dehydrogenase release and 30 and 100 microM over 90% lactate dehydrogenase release. The time course of cell damage was considerably faster for flunarizine, in comparison to dotarizine. Out of 30 molecules tested (at 10 microM), having different octanol/water partition coefficients (log P), dotarizine was among the molecules causing no cell damage; flunarizine caused 20% cell loss, lidoflazine and verapamil over 50% cell loss, and penfluridol, draflazine, astemizole or nifedipine over 80% cell loss. No correlation was found between log P and cytotoxicity. Both dotarizine (10-30 microM) and flunarizine (3-10 microM) provided protection against veratridine-induced cell death; however, at 30 microM dotarizine afforded a pronounced protection while flunarizine enhanced the cytotoxic effects of veratridine. Dotarizine (30 microM) (but not flunarizine) caused a prompt transient elevation of the basal [Ca2+]i. Both compounds abolished the K+-induced increases of [Ca2+]i as well as the oscillations of [Ca2+]i induced by veratridine. The blocking effects of dotarizine were readily reversed after washout, while those of flunarizine were long-lasting. These differences might be relevant to the clinical use of dotarizine as an antimigraine drug.