Impact of CYP2D6 and CYP2B6 phenotypes on the response to tramadol in patients with acute post-surgical pain.

Tramadol is an important minor opioid prescribed for pain management. In this study, we analyzed the well-known impact of CYP2D6 genetic variation and 60 additional variants in eight candidate genes (i.e., ABCG2, SLCO1B1, CYP2D6, CYP2B6, CYP2C19, CYP2C9, CYP3A5, and CYP3A4) on tramadol efficacy and safety. Some 108 patients with pain after surgery admitted to a post-anesthesia care unit (PACU) and prescribed tramadol were recruited. They were genotyped, and tramadol M1/M2 metabolite concentrations were determined by a newly validated HPLC-MS/MS method. CYP2D6 intermediate (IM) and poor (PM) metabolizers showed lower M1 concentrations adjusted for dose/weight at 30 and 120 min compared to ultrarapid (UM) and normal (NM) metabolizers (univariate p < 0.001 and 0.020, multivariate p < 0.001 and 0.001, unstandardized ß coefficients = 0.386 and 0.346, R2 = 0.146 and 0.120, respectively). CYP2B6 PMs (n = 10) were significantly related to a higher reduction in pain 30 min after tramadol intake (univariate p = 0.038, multivariate p = 0.016, unstandardized ß coefficient = 0.224, R2 = 0.178), to lower PACU admission time (p = 0.007), and to lower incidence of adverse drug reactions (p = 0.038) compared to the other phenotypes. CYP3A4 IMs and PMs showed a higher prevalence of drowsiness and dizziness (p = 0.028 and 0.005, respectively). Our results suggest that the interaction of CYP2B6 and CYP2D6 phenotypes may be clinically relevant, pending validation of these results in large, independent cohorts. Additional research is required to clarify the impact of CYP3A4 genetic variation on tramadol response.

Bortezomib Pharmacogenetic Biomarkers for the Treatment of Multiple Myeloma: Review and Future Perspectives.

Multiple myeloma (MM) is a hematological neoplasm for which different chemotherapy treatments are used with several drugs in combination. One of the most frequently used drugs for the treatment of MM is the proteasome inhibitor bortezomib. Patients treated with bortezomib are at increased risk for thrombocytopenia, neutropenia, gastrointestinal toxicities, peripheral neuropathy, infection, and fatigue. This drug is almost entirely metabolized by cytochrome CYP450 isoenzymes and transported by the efflux pump P-glycoprotein. Genes encoding both enzymes and transporters involved in the bortezomib pharmacokinetic pathway are highly polymorphic. The response to bortezomib and the incidence of adverse drug reactions (ADRs) vary among patients, which could be due to interindividual variations in these possible pharmacogenetic biomarkers. In this review, we compiled all pharmacogenetic information relevant to the treatment of MM with bortezomib. In addition, we discuss possible future perspectives and the analysis of potential pharmacogenetic markers that could influence the incidence of ADR and the toxicity of bortezomib. It would be a milestone in the field of targeted therapy for MM to relate potential biomarkers to the various effects of bortezomib on patients.

Use of Venetoclax in Patients with Relapsed or Refractory Acute Myeloid Leukemia: The PETHEMA Registry Experience.

The effectiveness of venetoclax (VEN) in relapsed or refractory acute myeloid leukemia (RR-AML) has not been well established. This retrospective, multicenter, observational database studied the effectiveness of VEN in a cohort of 51 RR-AML patients and evaluated for predictors of response and overall survival (OS). The median age was 68 years, most were at high risk, 61% received ≥2 therapies for AML, 49% had received hypomethylating agents, and ECOG was ≥2 in 52%. Complete remission (CR) rate, including CR with incomplete hematological recovery (CRi), was 12.4%. Additionally, 10.4% experienced partial response (PR). The CR/CRi was higher in combination with azacitidine (AZA; 17.9%) than with decitabine (DEC; 6.7%) and low-dose cytarabine (LDAC; 0%). Mutated NPM1 was associated with increased CR/CRi. Median OS was 104 days (95% CI: 56-151). For the combination with AZA, DEC, and LDAC, median OS was 120 days, 104 days, and 69 days, respectively; p = 0.875. Treatment response and ECOG 0 influenced OS in a multivariate model. A total of 28% of patients required interruption of VEN because of toxicity. Our real-life series describes a marginal probability of CR/CRi and poor OS after VEN-based salvage. Patients included had very poor-risk features and were heavily pretreated. The small percentage of responders did not reach the median OS.

Role of Pharmacogenetics in the Treatment of Acute Myeloid Leukemia: Systematic Review and Future Perspectives.

Acute myeloid leukemia (AML) is a heterogeneous disease characterized by remarkable toxicity and great variability in response to treatment. Plenteous pharmacogenetic studies have already been published for classical therapies, such as cytarabine or anthracyclines, but such studies remain scarce for newer drugs. There is evidence of the relevance of polymorphisms in response to treatment, although most studies have limitations in terms of cohort size or standardization of results. The different responses associated with genetic variability include both increased drug efficacy and toxicity and decreased response or resistance to treatment. A broad pharmacogenetic understanding may be useful in the design of dosing strategies and treatment guidelines. The aim of this study is to perform a review of the available publications and evidence related to the pharmacogenetics of AML, compiling those studies that may be useful in optimizing drug administration.

Use of Azacitidine or Decitabine for the Up-Front Setting in Acute Myeloid Leukaemia: A Systematic Review and Meta-Analysis.

Irruption of decitabine and azacitidine has led to profound changes in the upfront management of older acute myeloid leukaemia (AML). However, they have not been directly compared in a randomised clinical trial. In addition, there are no studies comparing the optimal treatment schedule of each drug in AML. A systematic review and meta-analysis on the efficacy of decitabine and azacitidine monotherapy in newly diagnosed AML was conducted. Randomised controlled trials and retrospective studies were included. A total of 2743 patients from 23 cohorts were analysed (10 cohorts of azacitidine and 13 of decitabine). Similar response rates were observed for azacitidine (38%, 95% CI: 30-47%) compared to decitabine (40%, 95% CI: 32-48%) (p = 0.825). Overall survival (OS) between azacitidine (10.04 months, 95% CI: 8.36-11.72) and decitabine (8.79 months, 95% CI: 7.62-9.96) was also similar (p = 0.386). Patients treated with azacitidine showed a lower median OS when azacitidine was administered for 5 days (6.28 months, 95% CI: 4.23-8.32) compared to the standard 7-day schedule (10.83 months, 95% CI: 9.07-12.59, p = 0.002). Among patients treated with decitabine, response rates and OS were not significantly different between 5-day and 10-day decitabine regimens. Despite heterogeneity between studies, we found no differences in response rates and OS in AML patients treated with azacitidine or decitabine.

Influence of Genetic Polymorphisms on the Response to Tramadol, Ibuprofen, and the Combination in Patients With Moderate to Severe Pain After Dental Surgery.

PURPOSE: We aimed to elucidate the influence on analgesic effect of genetic polymorphisms in enzymes responsible for biotransformation of tramadol and ibuprofen or other possible genes involved in their mechanism of action. METHODS: The study population comprised 118 patients from a multicenter, randomized, double-blind, placebo-controlled, Phase III clinical trial that assessed the analgesic efficacy and tolerability of a single dose of ibuprofen (arginine)/tramadol 400/37.5 mg compared with ibuprofen arginine 400 mg alone, tramadol 50 mg alone, and placebo in patients with moderate to severe pain after dental surgery. We analyzed 32 polymorphisms in the cytochrome P450 (CYP) enzymes COMT, ABCB1, SLC22A1, OPRM1, and SLC22A1. FINDINGS: We did not find any statistically significant difference among CYP2C9 phenotypes related to ibuprofen response, although CYP2C9 poor metabolizers had a longer effect (higher pain relief at 6 hours). Likewise, we did not find any statistically significant difference among PTGS2 genotypes, contradicting previously publications. IMPLICATIONS: There was not a clear effect of CYP2D6 phenotype on tramadol response, although CYP2D6 poor metabolizers had a slower analgesic effect. Concerning the transport of CYP2D6, we observed a better response in individuals carrying ABCB1 mutated alleles, which might correlate with higher tramadol plasma levels. Finally, we found a statistically significant better response in patients carrying the OPRM1 A118G G allele, which contradicts the previous reports. Measuring the active metabolite O-desmethyl-tramadol formation would be of great importance to better evaluate this association because O-desmethyl-tramadol has a higher µ-opioid receptor affinity compared with the parent drug. EudraCT.ema.europa.eu identifier: 2013-004637-33.

Important Pharmacogenetic Information for Drugs Prescribed During the SARS-CoV-2 Infection (COVID-19).

In December 2019, the severe acute respiratory syndrome virus-2 pandemic began, causing the coronavirus disease 2019. A vast variety of drugs is being used off-label as potential therapies. Many of the repurposed drugs have clinical pharmacogenetic guidelines available with therapeutic recommendations when prescribed as indicated on the drug label. The aim of this review is to provide a comprehensive summary of pharmacogenetic biomarkers available for these drugs, which may help to prescribe them more safely.

Risk of COVID-19 in oncohematological patients.

As of April 23, 2020, the COVID-19 (SARS-CoV-2) pandemic has affected 2,544,792 people, causing 175,694 deaths worldwide. The global scientific community has turned its attention to the impact of the new virus, which has become a major challenge for healthcare systems in many countries. Oncology patients have been considered of high risk within the ongoing COVID-19 pandemic. Oncology patients are especially vulnerable to infection due to the underlying disease and the type of therapy received. In general, the epidemiologic behavior of community-acquired respiratory viruses among oncology patients resembles that of the general population. Although, at present, there is limited data regarding COVID-19 and solid tumors, oncology patients seem to carry a higher risk of developing severe events. Yet, among patients harboring hematological diseases we have not observed an increase in COVID 19 infections.

Outpatient treatment of COVID-19 with steroids in the phase of mild pneumonia without the need for admission as an opportunity to modify the course of the disease: A structured summary of a randomised controlled trial.

OBJECTIVES: The aim of this study is to explore the effectiveness and safety of oral corticosteroids (prednisone) in the treatment of early stage SARS-Cov-2 pneumonia in patients who do not yet meet hospital admission criteria. TRIAL DESIGN: Randomized clinical trial, controlled, open, parallel group, to evaluate the effectiveness of steroids in adult patients with confirmed COVID-19, with incipient pulmonary involvement, without hospital admission criteria. Patients will be stratified by the presence or not of radiological data on pneumonia. PARTICIPANTS: We will include patients with early stage SARS-Cov-2 pneumonia who do not meet hospital admission criteria from the reference hospital, the Hospital Universitario de Burgos, in the region of Castilla y León, Spain. Patients will be followed-up by specialist physicians and Primary Health Care professionals. INCLUSION CRITERIA: - Men and women. - Age between 18 and 75 years old. - Diagnosed SARS-CoV-2 infection, by PCR and/or IgM+ antibody test and/or antigen test. - Clinical diagnosis of lung involvement: (respiratory symptoms +/- pathological auscultation +/- O2 desaturation) - Chest X-ray with mild-moderate alterations or normal. - Patients who give their verbal informed consent in front of witnesses, which will be reflected in the patients' medical records. EXCLUSION CRITERIA: - Oxygen desaturation below 93% or P02 < 62. - Moderate-severe dyspnea or significant respiratory or general deterioration that makes admission advisable. - Chest X-ray with multifocal infiltrates. - Insulin-dependent diabetes with poor control or glycaemia in the emergency room test greater than 300 mg/ml (fasting or not). - Other significant comorbidities: Severe renal failure (creatinine clearance < 30 mL/min); cirrhosis or chronic liver disease, poorly controlled hypertension. - Heart rhythm disturbances (including prolonged QT). - Severe immunosuppression (HIV infection, long-term use of immunosuppressive agents); cancer. - Pregnant or breast-feeding women. - Patients under use of glucocorticoids for other diseases. - History of allergy or intolerance to any of the drugs in the study (prednisone, azithromycin or hydroxychloroquine). - Patients who took one or more of the study drugs in the 7 days prior to study inclusion. - Patients taking non-suppressible drugs with risk of QT prolongation or significant interactions. - Patients unwilling or unable to participate until study completion. - Participation in another study. INTERVENTION AND COMPARATOR: Eligible patients will be randomized to receive standard outpatient treatment only (group 1) or standard outpatient treatment plus prednisone (group 2). - Group 1: paracetamol 1 g/8 h (on demand) + hydroxychloroquine 400 mg/12h the first day, 200 mg/12 h for 4 days + azithromycin 500 mg/24h for 5 days. - Group 2: paracetamol 1 g/8 h (on demand) + hydroxychloroquine 400 mg/12h the first day, 200 mg/12 h for 4 days + azithromycin 500 mg/24h for 5 days + prednisone 60 mg / 24 h for 3 days, 30 mg / 24 h for 3 days and 15 mg / 24 h for 3 days. MAIN OUTCOMES: If the patient requires ambulatory observation, according to the protocol established in this respect in the Emergency Department, meets all the criteria for inclusion and none for exclusion, data will be taken by the person responsible on the data collection sheet. The main result is admission after 30 days. Secondary outcomes are 30-day ICU admission and hospital stay. The safety variable will be the occurrence of clinical symptoms or delirium related to the steroids. Also, the possible decompensations of diabetes will be measured. All tests will be on an intention-to-treat basis. RANDOMISATION: Treatment will be assigned according to stratified randomization by the presence or absence of radiological data of lung involvement (previously performed by random sequence 1:1 generated with Epidat and kept hidden by opaque, sealed envelopes, which will only be opened after inclusion and basal measurement). BLINDING (MASKING): Participants, caregivers and personnel responsible for outcomes measurement will not be blinded to group assignment, once the patient is included and the basal measurement performed, as per protocol design. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): The percentage of patients with incipient lung involvement is unknown, but given that pulmonary involvement already exists it is estimated to be around 20%. We consider that the intervention could reduce this percentage to 5%, so the necessary sample size would be 200 subjects (100 per group), with a power of 80% and an estimated loss percentage of 10%. TRIAL STATUS: The protocol with code TAC-COVID-19, version 2.0 on date: April 16, 2020 is approved by the Spanish Drug Agency (AEMPS) and the local Ethics Committee. The trial is in the recruitment phase. Recruitment began 19 April, 2020 and is anticipated to be complete by April 2021. TRIAL REGISTRATION: The trial was registered under the title "OUTPATIENT TREATMENT OF EARLY PULMONARY COVID19 WITH CORTICOSTEROIDS AS AN OPPORTUNITY TO MODIFY THE COURSE OF THE DISEASE" with EudraCT number 2020-001622-64 , registered on 3 April 2020. FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Urgent Hospital Admissions Caused by Adverse Drug Reactions and Medication Errors-A Population-Based Study in Spain.

BACKGROUND: Adverse drug reactions (ADR) are a public health issue, due to their great impact on morbidity, mortality, and economic cost. OBJECTIVE: We aimed to study the percentage of patients admitted urgently as a result of an ADR, considered serious adverse event, or medication error. Also, we intended to identify possible risk factors which would lead to improvements in the prescription and use of medications. METHODS: This is a retrospective observational study conducted during February 2019, including patients admitted through the emergency department in our hospital. We evaluated the medical records of those with suspected ADR diagnoses to perform a descriptive analysis of the demographic characteristics. Moreover, after applying the Spanish Pharmacovigilance System causality algorithm, we performed a descriptive analysis of the identified ADR and the drugs involved. We also investigated those cases suspected of being a medication error. RESULTS: During the study period, 847 patients were urgently hospitalized. From those, 71 (29 women and 42 men) were admitted due to an ADR (8.4%, 95% CI 6.5%-10.3%). The mean age was 73 ± 15.9 years old and the mean number of prescribed medications was 7.3 ± 3.6 drugs/patient on admission. The most frequent ADR were opportunistic infections due to antineoplastic and immunomodulator drugs, and bleeding due to antiaggregants and anticoagulants. Five suspected medication errors occurred, being the incidence 0.6% (95% CI 0.08%-1.12%) of total admissions. CONCLUSIONS: 8.4% of urgent admissions were attributed to an ADR. Age (75% of patients were ≥ 65 years old), comorbidities and polymedication were the main risk factors. Although medication errors had a very low incidence (0.6% of urgent admissions), they were preventable and should be considered as a focus for action.

Effect of Cytochrome P450 and ABCB1 Polymorphisms on Imatinib Pharmacokinetics After Single-Dose Administration to Healthy Subjects.

BACKGROUND: Validated genomic biomarkers for oncological drugs are expanding to improve targeted therapies. Pharmacogenetics research focusing on the mechanisms underlying imatinib suboptimal response might help to explain the different treatment outcomes and drug safety profiles. OBJECTIVE: To investigate whether polymorphisms in genes encoding cytochrome P450 (CYP) enzymes and ABCB1 transporter affect imatinib pharmacokinetic parameters. METHODS: A prospective, multicenter, pharmacogenetic pilot study was performed in the context of two separate oral imatinib bioequivalence clinical trials, which included 26 healthy volunteers. DNA was extracted in order to analyze polymorphisms in genes CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP3A4, CYP3A5 and ABCB1. Imatinib plasma concentrations were measured by HPLC-MS/MS. Pharmacokinetic parameters were calculated by non-compartmental methods using WinNonlin software. RESULTS: Volunteers (n = 26; aged 24 ± 3 years; 69% male) presented regular pharmacokinetic imatinib data (concentration at 24 h, 436 ± 140 ng/mL and at 72 h, 40 ± 26 ng/mL; AUC0-72 32,868 ± 10,713 ng/mL⋅h; and Cmax 2074 ± 604 ng/mL). CYP2B6 516GT carriers showed a significant reduction of imatinib concentration at 24 h (23%, 391 ng/dL vs 511 ng/dL in 516GG carriers, p = 0.005) and elimination half-life (11%, 12.6 h vs 14.1 h in 516GG carriers, p = 0.041). Carriers for CYP3A4 (*22/*22, *1/*20 and *1/*22 variants) showed a reduced frequency of adverse events compared to *1/*1 carriers (0 vs 64%, p = 0.033). The other polymorphisms analyzed did not influence pharmacokinetics or drug toxicity. CONCLUSION: CYP2B6 G516T and CYP3A4 *20,*22 polymorphisms could influence imatinib plasma concentrations and safety profile, after single-dose administration to healthy subjects. This finding needs to be confirmed before it is implemented in clinical practice in oncological patients under treatment with imatinib.

Effect of Polymorphisms in CYP2C9 and CYP2C19 on the Disposition, Safety and Metabolism of Progesterone Administrated Orally or Vaginally.

INTRODUCTION: Exogenous progesterone is prescribed for a variety of conditions with endogenous progesterone deficiency, e.g. menstrual alterations, primary or secondary infertility or premenopause. To the best of our knowledge, no pharmacogenetic studies have been published in relation to exogenous progesterone pharmacokinetic safety or progesterone metabolites so far. METHODS: Candidate-gene study where we evaluated whether five single-nucleotide polymorphisms (CYP2C9*2, *3, CYP2C19*2, *3 and *17) were related to the pharmacokinetics, safety and metabolism of progesterone in 24 healthy volunteers who received a 200-mg progesterone formulation either orally or vaginally. RESULTS: The vaginal formulation had an average AUCt value approximately 18 times greater than the oral formulation. CYP2C19 intermediate metabolizers (IM) consistently showed higher adjusted AUCt and adjusted Cmax than extensive metabolizers (EM) (P < 0.05); CYP2C9 EM incongruently exhibited higher adjusted Cmax and longer half-life than IM (p < 0.05). CONCLUSION: This is the first study that reports variability in progesterone disposition according to the CYP2C19 and CYP2C9 phenotype. We suggest that CYP2C19 may condition progesterone disposition and that it may be more relevant than CYP2C9. This study lays the foundations for further in-depth research to evaluate the pharmacogenetics of progesterone. TRIAL REGISTRATION: EudraCT numbers are 2012-005105-43 and 2012-005011-10.

Polymorphisms in CYP1A2, CYP2C9 and ABCB1 affect agomelatine pharmacokinetics.

BACKGROUND: Agomelatine is an agonist of the melatoninergic receptors used for the treatment of depression. Our aim was to evaluate the effect of genetic polymorphisms in metabolising enzymes and the P-glycoprotein transporter on agomelatine pharmacokinetics and pharmacodynamics. METHODS: Twenty-eight healthy volunteers receiving a single 25 mg oral dose of agomelatine, were genotyped for nine polymorphisms in cytochrome P450 enzymes ( CYP1A2, CYP2C9 and CYP2C19) and adenosine triphosphate-binding cassette subfamily B member 1 ( ABCB1), by real-time polymerase chain reaction . Agomelatine concentrations were measured by high performance liquid chromatography coupled to a tandem mass spectrometry detector. RESULTS: We calculated a CYP1A2 activity score that was directly correlated with agomelatine pharmacokinetics. Individuals with a decreased enzyme activity (*1C carriers) had a lower clearance and accumulated higher concentrations of agomelatine. In contrast, individuals with a high CYP1A2 inducibility (*1F or *1B carriers) showed an extensive clearance and lower agomelatine concentrations. The apparently marked differences between races were due to the different CYP1A2 genotype distribution. CYP2C9 intermediate/poor metabolisers showed a higher area under the concentration-time curve and maximum concentration. ABCB1 G2677T/A polymorphism affected the time to reach maximum concentration, as subjects carrying A/A+A/T genotypes showed higher values. No association was found for CYP2C19 phenotype. Agomelatine did not produce any change in blood pressure, heart rate or QT interval. CONCLUSIONS: CYP1A2 polymorphisms affect agomelatine pharmacokinetics. CYP1A2 phenotype inferred from the genotyping of CYP1A2*1C, *1F and *1B alleles might be a potential predictor of agomelatine exposure. ABCB1 G2677T/A could affect agomelatine absorption, as subjects with A/A+A/T genotypes had lower agomelatine concentration and they take more time to reach the maximum concentration.

Influence of thiopurine S-methyltransferase polymorphisms in mercaptopurine pharmacokinetics in healthy volunteers.

Mercaptopurine is a drug commonly used in the treatment of different types of cancer, especially acute lymphoblastic leukaemia, and autoimmune diseases such as ulcerative colitis or Crohn's disease and in patients receiving organ transplants. It is metabolized by three cytosolic enzymes. One of them, thiopurine S-methyltransferase (TPMT), is responsible for catalysing the methylation reaction of mercaptopurine to 6-methylmercaptopurine, thus inactivating the drug. Individuals with TPMT loss-of-function alleles (*2, *3A, *3B or *3C) can be extremely sensitive to the effect of mercaptopurine, since it can be accumulated, therefore producing haematological toxicity. The objective of this study was to evaluate the role of TPMT polymorphisms on the pharmacokinetics of mercaptopurine. For that purpose, we used collected pharmacokinetic data from 48 healthy volunteers (all males) who received a single oral dose of mercaptopurine 50 mg in two bioequivalence studies. The volunteers were subsequently genotyped for TPMT *2, *3A, *3B and *3C alleles by real-time PCR. There were four carriers (8.3%) of TPMT*2 and TPMT*3A alleles. Mercaptopurine elimination was affected by TPMT loss-of-function polymorphisms, since heterozygous subjects show 18% higher half-life compared to wild-type individuals. This fact is consistent with the expected since the presence of loss-of-function alleles decreases TPMT enzymatic activity and, thus, affects mercaptopurine elimination. Moreover, mercaptopurine pharmacokinetic parameters were different among races, since Latins showed higher plasma concentrations and lower clearance compared to Caucasians. This fact might be due to a different distribution of polymorphisms in genes, other than TPMT, that also influence the pharmacokinetics of mercaptopurine.

How to make P-glycoprotein (ABCB1, MDR1) harbor mutations and measure its expression and activity in cell cultures?

Several polymorphisms have been identified in ABCB1, the gene encoding for the P-glycoprotein. This transporter alters the pharmacokinetics or effectiveness of drugs by excreting them from cells where it is expressed (e.g., blood-brain barrier, intestine or tumors). No consensus has been reached regarding the functional consequences of these polymorphisms in the transporter's function. The aim of this review was to describe a methodology that allows the assessment of P-gp function when harboring polymorphisms. We describe how to obtain cell lines with high expression levels of the transporter with polymorphisms and several tactics to measure its expression and activity. This methodology may help elucidate the contribution of polymorphisms in ABCB1 to drug pharmacokinetics, effectiveness and safety or to cancer chemotherapy failure.

Histone modifications associated with biological drug response in moderate-to-severe psoriasis.

INTRODUCTION: Epigenetic factors play an important role in psoriasis onset and development. Biological drugs are used to treat moderate-to-severe psoriasis patients resistant to conventional systemic drugs. Although they are safe and effective, some patients do not respond to them. Therefore, it is necessary to find biomarkers that could predict response to these therapies. OBJECTIVE: To find epigenetic biomarkers that could predict response to biological drugs (ustekinumab, secukinumab, adalimumab, ixekizumab). MATERIALS AND METHODS: Peripheral blood mononuclear cells (PBMCs) were isolated from 39 psoriasis patients treated with biological therapies before and after drug administration and from 42 healthy subjects. Afterwards, histones were extracted from PBMCs. Four histone modifications (H3 and H4 acetylation, H3K4 and H3K27 methylation) were determined by ELISA. Data were analysed by IBM-SPSS v.23. RESULTS AND CONCLUSIONS: Psoriasis patients presented reduced levels of acetylated H3 and H4 and increased levels of methylated H3K4 compared to controls. Non-significant changes were observed after treatment administration in any of the histone modifications analysed. Nevertheless, significant changes in methylated H3K27 were found between responders and non-responders to biological drugs at 3 months. As 28% of these patients also presented psoriatic arthritis (PsA), the former analysis was repeated in the subsets of patients with or without PsA. In patients without PsA, significant changes in methylated H3K4 were found between responders and non-responders to biological drugs at 3 and 6 months. Although further studies should confirm these results, these findings suggest that H3K27 and H3K4 methylation may contribute to patients' response to biological drugs in psoriasis.

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.