UGT1A1 Polymorphisms Research Articles

Effect of UGT1A6 and UGT2B7 polymorphisms on the valproic acid serum concentration and drug-induced liver injury.

Aim: Valproic acid (VPA) is a classic broad-spectrum antiepileptic drug, with significant pharmacokinetic variability. Genetic polymorphisms contribute to this variability, influencing both VPA trough serum concentration (VPA concentration) and VPA-induced liver injury. Our study aims to investigate the association between polymorphisms of uridine diphosphate glucuronyl transferase (UGT) 1A6, UGT2B7 and VPA concentration and screen for potential genetic loci affecting VPA-induced liver injury.Methods: This study included epilepsy patients treated with VPA. PCR-RFLP method was used to determine the genotypes of UGT1A6 and UGT2B7. Chemiluminescent microparticle immunoassay was used to measure VPA concentration. Multiple linear regression and logistic regression were employed to analyze factors influencing VPA concentration and VPA-induced liver injury, respectively.Results: The correlation between UGT polymorphism and VPA concentration was analyzed in 133 samples. For VPA-induced liver injury, 105 patients were analyzed, with 29 in the liver injury group and 76 in the control group. Our finding showed patients with the UGT1A6-T19G variant had significantly lower VPA concentrations compared with wild-type patients and UGT1A6-T19G, A541G, A552C and UGT2B7-C802T, G211T, A268G polymorphisms showed no impact on VPA-induced liver injury.Conclusion: This study demonstrated UGT1A6-T19G polymorphisms affected the VPA concentration, providing a theoretical basis for the individualized clinical use of VPA.

Interpreting elevated liver blood test results through a genetic lens: A genome-wide association study.

Individuals with genetic polymorphisms in UGT1A1 exhibit bilirubin levels that belie their risk of liver disease (Gilbert's syndrome) but it is not known if this phenomenon extends to other common liver blood tests (LBTs). A genome-wide association analysis of 10 LBTs was conducted using the UK biobank. Polygenic scores (PGS) were created from discordant loci (e.g. loci associated with the LBT but not associated with cirrhosis morbidity risk). Participants were assigned to a low, intermediate or high PGS for each LBT. A high PGS approximates Gilbert's syndrome (i.e. elevated LBT without an analogous increase in disease risk). The prognostic significance of an 'elevated' LBT-and how this differs by PGS-was assessed through competing risk survival analysis. This study included 157 005 and 166 871 participants for the discovery and validation phases, respectively. Elevated LBTs were more prevalent in the high versus low PGS group, yet the 10-year risk of cirrhosis morbidity was comparable. For example, in the low PGS group, 4.3% had an elevated gamma-glutamyltransferase (GGT) and the 10-year risk of cirrhosis morbidity was .45%. Conversely, in the high PGS group, 21.2% had an elevated GGT and the 10-year risk was .38%. Accordingly, the 10-year risk of cirrhosis morbidity for individuals with an elevated GGT was markedly different in the low vs. high group (4.2% vs. 1.2%; p < .001). Similar results were apparent for Fibrosis-4 index, total bilirubin, and platelet count. Variability in LBTs is influenced by genetic polymorphisms that have a neutral effect on disease risk. These findings have implications for interpreting elevated LBTs in clinical practice.

ERCC1 and ERCC2 Polymorphisms Predict the Efficacy and Toxicity of Platinum-Based Chemotherapy in Small Cell Lung Cancer.

Standard first-line chemotherapy in small cell lung cancer (SCLC) is based on the platinum plus etoposide combination. Despite a high objective response rate, responses are not durable and chemotherapy-induced toxicity may compromise treatment. Genetic variants in genes involved in the DNA-repair pathways and in etoposide metabolization could predict treatment efficacy and safety and help personalize platinum-based chemotherapy. Germline polymorphisms in XRCC1, ERCC1, ERCC2, ABCB1, ABCC3, UGT1A1 and GSTP1 genes were investigated in 145 patients with SCLC. The tumor expression of ERCC1 was determined using immunohistochemistry, and the tumor expression of ERCC1-XPF was determined via a proximity ligation assay. Survival analyses showed a statistically significant association between the ERCC1 rs11615 variant and median progression-free survival (PFS) in patients with limited-stage (LS) SCLC (multivariate: hazard ratio 3.25, [95% CI 1.38-7.70]; p = 0.007). Furthermore, we observed differences between the ERCC1-XPF complex and median PFS in LS-SCLC, although statistical significance was not reached (univariate: positive expression 10.8 [95% CI 4.09-17.55] months versus negative expression 13.3 [95% CI 7.32-19.31] months; p = 0.06). Safety analyses showed that the ERCC2 rs1799793 variant was significantly associated with the risk of grade ≥ 3 thrombocytopenia in the total cohort (multivariate: odds ratio 3.15, [95% CI 1.08-9.17]; p = 0.04). Our results provide evidence that ERCC1 and ERCC2 variants may predict the efficacy and safety of platinum-based chemotherapy in SCLC patients. LS-SCLC patients may benefit most from ERCC1 determination, but prospective studies are needed.

UGT1A1*28 polymorphism and the risk of toxicity and disease progression in patients with breast cancer receiving sacituzumab govitecan.

Sacituzumab govitecan (sacituzumab) emerged as an important agent in metastatic and locally recurrent HER2-negative breast cancer treatment. UGT1A1 polymorphisms have also been shown to predict sacituzumab toxicity. In this retrospective study, we sought to evaluate the associations between UGT1A1 status, toxicity, and therapeutic outcomes in sacituzumab recipients with advanced breast cancer who underwent genotype testing for UGT1A1 alleles (N = 68). We found 17 (25%) of our patients to be homozygous for UGT1A1*28 and 24 (35.3%) were heterozygous. Of seven African American patients with triple-negative breast cancer, five were homozygous for UGT1A1*28 and two were heterozygous. Patients with a homozygous UGT1A1*28 genotype were significantly more likely to have treatment terminated because of adverse effects. However, the polymorphism was not associated with treatment discontinuation because of disease progression. This retrospective, real-world analysis suggests potential clinical utility in UGT1A1 testing for patients receiving sacituzumab, but future trials are needed to confirm the association between genotypes and treatment outcomes.

Polycyclic aromatic hydrocarbon and its adducts in peripheral blood: Gene and environment interaction among Chinese population

BackgroundBenzo(a)pyrene (B[a]P) is the most widely concerned polycyclic aromatic hydrocarbons (PAHs), which metabolizes benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE) in vivo to produce carcinogenic effect on the body. Currently, there is limited research on the role of the variation of metabolic enzymes in this process. MethodsWe carried out a study including 752 participants, measured the concentrations of 16 kinds PAHs in both particle and gaseous phases, urinary PAHs metabolites, leukocyte BPDE-DNA adduct and serum BPDE- Albumin (BPDE-Alb) adduct, and calculated daily intake dose (DID) to assess the cumulative exposure of PAHs. We conducted single nucleotide polymorphism sites (SNPs) of metabolic enzymes, explored the exposure–response relationship between the levels of exposure and BPDE adducts using multiple linear regression models. ResultOur results indicated that an interquartile range (IQR) increase in B[a]P, PAHs, BaPeq, 1-hydroxypyrene (1-OHP), 1-hydroxynaphthalene (1-OHNap) and 2-hydroxynaphthalene (2-OHNap) were associated with 26.53 %, 24.24 %, 28.15 %, 39.15 %, 12.85 % and 14.09 % increase in leukocyte BPDE-DNA adduct (all P < 0.05). However, there was no significant correlation between exposure with serum BPDE-Alb adduct (P > 0.05). Besides, we also found the polymorphism of CYP1A1(Gly45Asp), CYP2C9 (Ile359Leu), and UGT1A1(downstream) may affect BPDE adducts level. ConclusionOur results indicated that leukocyte BPDE-DNA adduct could better reflect the exposure to PAHs. Furthermore, the polymorphism of CYP1A1, CYP2C9 and UGT1A1affected the content of BPDE adducts.

Influence of UDP-Glucuronosyltransferase Polymorphisms on Mycophenolic Acid Metabolism in Renal Transplant Patients

This study aims to evaluate the effects of the UDP-glucuronosyltransferases (UGTs) polymorphisms on mycophenolic acid (MPA) metabolites in renal transplant patients. Total 11 single nucleotide polymorphisms (SNPs) of UGT1A1, UGT1A7, UGT1A8, UGT1A9, UGT1A10 and UGT2B7 were genotyped in 79 renal transplant patients. The associations of SNPs and clinical factors with dose-adjusted MPA area under the plasma concentration-time curve (AUC/D), the dose-adjusted concentration (C0/D) of MPAG and the dose-adjusted plasma concentration (C0/D) of AcMPAG were analyzed. In the univariate analysis, UGT1A1 rs4148323, age and anion gap were associated with MPA AUC/D. MPA AUC/D in patients with the GA genotype of UGT1A1 rs4148323 was higher than that in patients with the GG genotype. UGT1A1 rs4148323, UGT1A9 rs2741049 and clinical factors, including age, serum total bilirubin, adenosine deaminase, anion gap, urea, creatinine, were associated with MPAG C0/D. In addition, UGT2B7 rs7438135, UGT2B7 rs7439366, and UGT2B7 rs7662029 were associated with AcMPAG C0/D. Multiple linear regression analysis showed that UGT1A9 rs2741049 and indirect bilirubin were negatively correlated with MPAG C0/D (P=0.001; P=0.039). UGT2B7 rs7662029 was positively correlated with AcMPAG C0/D (P=0.008). In conclusion, the study shows a significant influence of UGT1A9 rs2741049 and UGT2B7 rs7662029 polymorphisms on the metabolism of MPA in vivo.

Association of UGT1A6 gene polymorphisms with sodium valproate-induced tremor in patients with epilepsy

BackgroundIndividual susceptibility to sodium valproate (VPA)-induced tremors may be due to genetic polymorphisms in the gene encoding the uridine diphosphate glucuronosyltransferase (UGT) enzyme, which affec the drug's clinical efficacy and cause toxic side effects. This study aimed to investigate the association between UGT1A6 polymorphisms and VPA-induced tremors in patients with epilepsy. MethodsIn total, 128 patients with epilepsy were enrolled. Patients with epilepsy who received VPA were divided into tremor and non-tremor groups. Polymerase chain reaction-restriction fragment length polymorphism was used to investigate the genotype of UGT1A6 polymorphisms. ResultsCarriers of the UGT1A6 A541G mutant genotype conferred a higher risk of tremor than wild-type carriers (odds ratio 2.128, P = 0.045). Logistic regression analysis showed that the A541G mutant genotype was a significant genetic risk factor for VPA-induced tremors. This suggests that individual susceptibility to VPA-induced tremors may result, at least partially, from genetic variation in UGT1A6 A541G. ConclusionsPatients with epilepsy carrying the UGT1A6 A541G mutant genotype may have VPA-induced tremors, and early detection of this genotype will help guide the clinical individualizsation of VPA treatment.

Perioperative sacituzumab govitecan (SG) alone or in combination with pembrolizumab (Pembro) for patients with muscle-invasive urothelial bladder cancer (MIBC): SURE-01/02 interim results.

LBA4517 Background: SG is an antibody-drug conjugate composed of an anti-trophoblast cell surface antigen 2 (Trop-2) antibody coupled to SN-38 (a topoisomerase-I inhibitor) with US FDA-accelerated approval for locally advanced or metastatic urothelial carcinoma (mUC). A multi-cohort, open-label, phase 2 SURE study is evaluating neoadjuvant SG (SURE-01, NCT05226117) or neoadjuvant SG+pembrolizumab followed by adjuvant pembrolizumab (SURE-02, NCT05535218) in MIBC in a flexible design allowing a bladder-sparing approach. We report interim results from SURE-01. Methods: Pts with cT2-4N0M0 MIBC who were ineligible for or refused cisplatin-based neoadjuvant chemotherapy were planned to receive 4 cycles of neoadjuvant SG 10 mg/kg intravenously (IV) on days 1 and 8, Q3W, followed by radical cystectomy (RC). The trial included pre-post MRI imaging of the pelvis and ctDNA analysis. Pts with clinical complete response (cCR, defined with negative MRI, cystoscopy and ctDNA assays) refusing RC were offered redo transurethral resection of the bladder tumor (reTURBT) followed by observation in case no viable high-grade tumor in the bladder was found. The primary endpoint of the study is to assess the proportion of ypT0N0. The assumptions include a ypT0N0≤20% as H0 and ≥45% as H1 in a single-stage A’Hern’s design. Secondary end points include event-free survival (EFS), cCR rate and OS. Treatment-related adverse events (TRAEs) and safety are assessed using standard criteria (CTCAE v5). Tumor samples underwent comprehensive genomic profiling assay. Results: From 03/22 to 11/23, 21 pts were enrolled. After the initial 8 pts the study was amended with SG at 7.5 mg/Kg dose due to a Grade 5 TRAE. Median age was 71y, 7 pts (33.3%) had a cT3-4N0. Ten pts (47.6%) had a mixed variant histology. All pts received at least 1 cycle of SG: Grade ≥3 TRAE occurred in 9 pts (42.5%), including one Grade 5 event (at 10mg/Kg dose). Toxicity was unrelated to UGT1A1 polymorphism. Ten pts (47.6%) achieved a cCR. Sixteen pts are evaluable for final response at treatment completion: one pt had a disease progression and started palliative therapy, two did not undergo RC due to TRAE. Thirteen pts have undergone surgery (RC: N=10; reTURBT: N=3). ypT0N0-x response was achieved in 6/16 pts (37.5%), 7 (43.7%) an ypT≤1N0-x response. All pts with a residual disease revealed a ctDNA-negative test post-RC. Tumor samples from pts with cCR were enriched in ARID1A and BRCA1/2 mutations vs nonCR: 40 vs 9%, 30 vs 18%; nonCR were enriched in ERBB2 mutations vs cCR: 44 vs 10%. Conclusions: Observed ypT0N0-x responses after neoadjuvant SG showed promising activity in MIBC who have a high unmet need, with a potential to avoid RC. Reduced dose of SG was feasible and the data support the ongoing SURE studies in MIBC. Clinical trial information: NCT05226117 ; NCT05535218 .

Rapid detection of the irinotecan-related UGT1A1 & 5-fluorouracil related DPYD polymorphism by asymmetric polymerase chain reaction melting curve analysis

BackgroundDetermination of DPYD and UGT1A1 polymorphisms prior to 5-fluorouracil and irinotecan therapy is crucial for avoiding severe adverse drug effects. Hence, there is a pressing need for accurate and reliable genotyping methods for the most common DPYD and UGT1A1 polymorphisms. In this study, we introduce a novel polymerase chain reaction (PCR) melting curve analysis method for discriminating DPYD c.1236G > A, c.1679 T > G, c.2846A > T, IVS14 + 1G > A and UGT1A1*1, *28, *6 (G71R) genotypes. MethodsFollowing protocol optimization, this technique was employed to genotype 28 patients, recruited between March 2023 and October 2023, at the First Affiliated Hospital of Xiamen University. These patients included 20 with UGT1A1 *1/*1, 8 with UGT1A1 *1/*28, 4 with UGT1A1 *28/*28, 22 with UGT1A1*6 G/G, 6 with UGT1A1*6 G/A, 4 with UGT1A1*6 A/A, 27 with DPYD(c.1236) G/G, 3 with DPYD(c.1236) G/A, 2 with DPYD(c.1236) A/A, 27 with DPYD(c.1679) T/T, 2 with DPYD(c.1679) T/G, 3 with DPYD(c.1679) G/G, 28 with DPYD(c.2846A/T) A/A, 2 with DPYD(c.2846A/T) A/T, 2 with DPYD(c.2846A/T) T/T, 28 with DPYD(c.IVS14 + 1) G/G, 2 with DPYD(c.IVS14 + 1) G/G, and 2 with DPYD(c.IVS14 + 1) G/G, as well as 3 plasmid standards. Method accuracy was assessed by comparing results with those from Sanger sequencing or Multiplex quantitative PCR(qPCR). Intra- and inter-run precision of melting temperatures (Tms) were calculated to evaluate reliability, and sensitivity was assessed through limit of detection examination. ResultsThe new method accurately identified all genotypes and exhibited higher accuracy than Multiplex qPCR. Intra- and inter-run coefficients of variation for Tms were both ≤1.97 %, with standard deviations ≤0.95 °C. The limit of detection was 0.09 ng/μL of input genomic DNA. ConclusionOur developed PCR melting curve analysis offers accurate, reliable, rapid, simple, and cost-effective detection of DPYD and UGT1A1 polymorphisms. Its application can be easily extended to clinical laboratories equipped with a fluorescent PCR platform.

Combination of UGT1A1 polymorphism and baseline plasma bilirubin levels in predicting the risk of antipsychotic-induced dyslipidemia in schizophrenia patients.

The prolonged usage of atypical antipsychotic drugs (AAPD) among individuals with schizophrenia often leads to metabolic side effects such as dyslipidemia. These effects not only limit one's selection of AAPD but also significantly reduce compliance and quality of life of patients. Recent studies suggest that bilirubin plays a crucial role in maintaining lipid homeostasis and may be a potential pre-treatment biomarker for individuals with dyslipidemia. The present study included 644 schizophrenia patients from two centers. Demographic and clinical characteristics were collected at baseline and 4 weeks after admission to investigate the correlation between metabolites, episodes, usage of AAPDs, and occurrence of dyslipidemia. Besides, we explored the combined predictive value of genotypes and baseline bilirubin for dyslipidemia by employing multiple PCR targeted capture techniques to sequence two pathways: bilirubin metabolism-related genes and lipid metabolism-related genes. Our results indicated that there existed a negative correlation between the changes in bilirubin levels and triglyceride (TG) levels in patients with schizophrenia. Among three types of bilirubin, direct bilirubin in the baseline (DBIL-bl) proved to be the most effective in predicting dyslipidemia in the ROC analysis (AUC = 0.627, p < 0.001). Furthermore, the odds ratio from multinomial logistic regression analysis showed that UGT1A1*6 was a protective factor for dyslipidemia (ß = -12.868, p < 0.001). The combination of baseline DBIL and UGT1A1*6 significantly improved the performance in predicting dyslipidemia (AUC = 0.939, p < 0.001). Schizophrenia patients with UGT1A1*6 mutation and a certain level of baseline bilirubin may be more resistant to dyslipidemia and have more selections for AAPD than other patients.

Assessing Pharmacogenomic loci Associated with the Pharmacokinetics of Vamorolone in Boys with Duchenne Muscular Dystrophy.

Human genetic variation (polymorphisms) in genes coding proteins involved in the absorption, distribution, metabolism, and elimination (ADME) of drugs can have a strong effect on drug exposure and downstream efficacy and safety outcomes. Vamorolone, a dissociative steroidal anti-inflammatory drug for treating Duchenne muscular dystrophy (DMD), primarily undergoes oxidation by CYP3A4 and CYP3A5 and glucuronidation by UDP-glucuronosyltransferases. This work assesses the pharmacokinetics (PKs) of vamorolone and sources of interindividual variability (IIV) in 81 steroid-naïve boys with DMD aged 4 to <7 years old considering the genetic polymorphisms of CYPS3A4 (CYP3A4*22, CYP3A4*1B), CYP3A5 (CYP3A5*3), and UGT1A1 (UGT1A1*60) utilizing population PK modeling. A one-compartment model with zero-order absorption (Tk0, duration of absorption), linear clearance (CL/F), and volume (V/F) describes the plasma PK data for boys with DMD receiving a wide range of vamorolone doses (0.25-6 mg/kg/day). The typical CL/F and V/F values of vamorolone were 35.8 L/h and 119 L, with modest IIV. The population Tk0 was 3.14 h yielding an average zero-order absorption rate (k0) of 1.16 mg/kg/h with similar absorption kinetics across subjects at the same vamorolone dose (i.e., no IIV on Tk0). The covariate analysis showed that none of the genetic covariates had any significant impact on the PKs of vamorolone in boys with DMD. Thus, the PKs of vamorolone is very consistent in these young boys with DMD.

Current Progress on the Influence Human Genetics Has on the Efficacy of Tyrosine Kinase Inhibitors Used to Treat Chronic Myeloid Leukemia.

The use of tyrosine kinase inhibitors (TKIs) has become the mainstay of treatment in patients suffering from chronic myeloid leukemia (CML), an adult leukemia caused by a reciprocal translocation between chromosomes 9 and 22, which createsan oncogene resulting in a myeloproliferative neoplasm. These drugs function by inhibiting the ATP-binding site on the fusion oncoprotein andsubsequently halting proliferative activity. The goal of this work is to investigate the current state of research into genetic factors that influence the efficacy of four FDA-approved TKIs used to treat CML. This overview attempts to identify genetic criteria that could be considered when choosing one drug over the others and to identify where more research is needed. Our results suggest thatthe usual liver enzymes impacting patient response may not be a major factor affecting the efficacy of imatinib, nilotinib, and bosutinib, and yet, that is where most of the past research has focused. More research is warranted on the impact that human polymorphisms of the CYP enzymes have on dasatinib. The impact of polymorphisms in UGT1A1 should be investigated thoroughly in other TKIs, not only nilotinib.The role of influx and efflux transporters has been inconsistent thus far, possibly due to failures to account for the multiple proteins that can transport TKIs and the impact that tumors have on transporter expression. Because physicians cannot currently use a patient's genetic profile to better target their treatment withTKIs, it is critical that more research be conducted on auxiliary pathways or off-target binding effects to generate new leads for further study. Hopefully, new avenues of research will help explain treatment failures and improve patient outcomes.

UGT1A polymorphism rs4148324 associated with topiramate plasma concentration to dose ratio in children with epilepsy.

The objective of this study is to evaluate the association between genetic polymorphisms and the concentration to dose ratio of topiramate in children with epilepsy. A cohort of 163 pediatric patients with epilepsy receiving topiramate therapy were enrolled. The ultra-performance liquid chromatography-tandem mass spectrometry method was employed to measure the trough plasma concentration of topiramate at steady-state. These concentrations were normalized by dividing them by the ratio of total daily dose to body weight, yielding the concentration to dose ratio (CDR) of topiramate. MassArray system identified 30 single nucleotide polymorphisms associated with the pharmacokinetics and pharmacodynamics of topiramate. The CDR values were logarithmic transformed (lnCDR) for normal distribution. The association between the identified genetic polymorphisms and lnCDR was assessed using the PLINK software, employing linear regression analysis with adjustments by epilepsy types, estimated glomerular filtration rate, alanine aminotransferase, valproic acid, phenobarbital, and oxcarbazepine. Variant rs4148324 (UGT1A1/3/4/5/6/7/8/9/10, BETA=0.182, P = 0.010) was significantly associated with lnCDR of topiramate. Patients carrying the G allele exhibited higher normalized topiramate plasma concentrations. No other significant associations were found. In pediatric patients receiving topiramate therapy, rs4148324 was associated with normalized topiramate plasma concentration. Further studies are warranted to validate and confirm the findings.

Genotyping of &lt;i&gt;UGT1A1&lt;/i&gt; and &lt;i&gt;DPYD&lt;/i&gt; polymorphisms in patients with colorectal cancer. A review

The main treatment regimen for patients with metastatic colorectal cancer is still cycle-based chemotherapy with fluoropyridines combined with oxaliplatin and/or irinotecan. The activity of these chemotherapeutic agents depends on a predominant specific metabolism pathway. Therefore, the genetic features of the patient become important as a prognostic factor for the occurrence and severity of adverse events during therapy. The review addresses current views about the mechanisms of toxic activity of irinotecan and fluoropyrimidines, analyzes the results of pharmacogenotyping of UGT1A1 and DPYD polymorphisms, and published studies assessing the relationship between genetic variants of these genes and the safety of chemotherapy. A significant role of the population component is noted both in the distribution of gene allele frequencies and in their phenotypic expression. For some polymorphisms of the DPYD gene, dose-dependent associations with the toxicity of 5-fluorouracil have been established. Nevertheless, they determine only 1–8% of cases out of 40–60% of patients with adverse events and DPD protein deficiency associated with other enzyme activity reduction mechanisms. The pharmacological significance of UGT1A1 genetic variations is associated with toxicity prediction and helps allocate patients for more effective high-dose irinotecan therapy. Data is presented on the pharmacogenotyping of these markers to establish the dose of drugs in various national guidelines. Currently, the heterogeneity of the available pharmacogenetic data leaves open the question of determining the most appropriate dosing strategies for irinotecan and fluoropyrimidines. The widespread introduction of UGT1A1 and DPYD genotyping into clinical practice balances the economic feasibility and predictive value of biomarkers. As pharmacogenomics evolves rapidly, more robust research would overcome existing hurdles and facilitate personalized drug dosage decisions.

Determinants of early change in serum creatinine after initiation of dolutegravir-based antiretroviral therapy in South Africa.

Dolutegravir increases serum creatinine by inhibiting its renal tubular secretion and elimination. We investigated determinants of early changes in serum creatinine in a southern African cohort starting first-line dolutegravir-based antiretroviral therapy (ART). We conducted a secondary analysis of data from participants in a randomized controlled trial of dolutegravir, emtricitabine and tenofovir disoproxil fumarate (TDF) or tenofovir alafenamide fumarate (TAF) (ADVANCE, NCT03122262). We assessed clinical, pharmacokinetic and genetic factors associated with change in serum creatinine from baseline to Week 4 using linear regression models adjusted for age, sex, baseline serum creatinine, HIV-1 RNA concentration, CD4 T-cell count, total body weight and co-trimoxazole use. We included 689 participants, of whom 470 had pharmacokinetic data and 315 had genetic data. Mean change in serum creatinine was 11.3 (SD 9.9)μmol.L-1. Factors that were positively associated with change in serum creatinine at Week 4 were increased log dolutegravir area under the 24-h concentration-time curve (change in creatinine coefficient [β] = 2.78 μmol.L-1 [95% confidence interval (CI) 0.54, 5.01]), TDF use (β = 2.30 [0.53, 4.06]), male sex (β = 5.20 [2.92, 7.48]), baseline serum creatinine (β = -0.22 [-0.31, -0.12]) and UGT1A1 rs929596 A→G polymorphism with a dominant model (β = -2.33 [-4.49, -0.17]). The latter did not withstand correction for multiple testing. Multiple clinical and pharmacokinetic factors were associated with early change in serum creatinine in individuals initiating dolutegravir-based ART. UGT1A1 polymorphisms may play a role, but further research on genetic determinants is needed.

Associations between UGT1A1, SLCO1B1, SLCO1B3, BLVRA and HMOX1 polymorphisms and susceptibility to neonatal severe hyperbilirubinemia in Chinese Han population

BackgroundSevere neonatal hyperbilirubinemia could lead to kernicterus and neonatal death. This study aimed to analyze the association between single nucleotide polymorphisms in genes involved in bilirubin metabolism and the incidence of severe hyperbilirubinemia.MethodsA total of 144 neonates with severe hyperbilirubinemia and 50 neonates without or mild hyperbilirubinemia were enrolled in 3 institutions between 2019 and 2020. Twelve polymorphisms of 5 genes (UGT1A1, SLCO1B1, SLCO1B3, BLVRA, and HMOX1) were analyzed by PCR amplification of genomic DNA. Genotyping was performed using an improved multiplex ligation detection reaction technique based on ligase detection reaction.ResultsThe frequencies of the A allele in UGT1A1-rs4148323 and the C allele in SLCO1B3-rs2417940 in the severe hyperbilirubinemia group (30.2% and 90.6%, respectively) were significantly higher than those in the controls (30.2% vs.13.0%, 90.6% vs. 78.0%, respectively, both p < 0.05). Haplotype analysis showed the ACG haplotype of UGT1A1 were associated with an increased hyperbilirubinemia risk (OR 3.122, p = 0.001), whereas the GCG haplotype was related to a reduced risk (OR 0.523, p = 0.018).ConclusionThe frequencies of the A allele in rs4148323 and the C allele in rs2417940 are highly associated with the incidence of severe hyperbilirubinemia in Chinese Han neonates.Trial registrationTrial registration number:ChiCTR1800020424; Date of registration:2018-12-29.

Nanoscale Bilirubin Analysis in Translational Research and Precision Medicine by the Recombinant Protein HUG.

Bilirubin is a toxicological biomarker for hemolysis and liver diseases. The current automated diazo method used in clinical chemistry has limited applicability in rodent models and cannot be used in small animals relevant to toxicology, microphysiological systems, cell cultures, and kinetic studies. Here, we present a versatile fluorometric method for nanoscale analysis of bilirubin based on its highly specific binding to the recombinant bifunctional protein HELP-UnaG (HUG). The assay is sensitive (LoQ = 1.1 nM), accurate (4.5% relative standard error), and remarkably robust, allowing analysis at pH 7.4-9.5, T = 25-37 °C, in various buffers, and in the presence of 0.4-4 mg × L-1 serum albumin or 30% DMSO. It allows repeated measurements of bilirubinemia in murine models and small animals, fostering the 3Rs principle. The assay determines bilirubin in human plasma with a relative standard error of 6.7% at values that correlate and agree with the standard diazo method. Furthermore, it detects differences in human bilirubinemia related to sex and UGT1A1 polymorphisms, thus demonstrating its suitability for the uniform assessment of bilirubin at the nanoscale in translational and precision medicine.

Applied physiologically-based pharmacokinetic modeling to assess uridine diphosphate-glucuronosyltransferase-mediated drug-drug interactions for Vericiguat.

Vericiguat (Verquvo; US: Merck, other countries: Bayer) is a novel drug for the treatment of chronic heart failure. Preclinical studies have demonstrated that the primary route of metabolism for vericiguat is glucuronidation, mainly catalyzed by uridine diphosphate-glucuronosyltransferase (UGT)1A9 and to a lesser extent UGT1A1. Whereas a drug-drug interaction (DDI) study of the UGT1A9 inhibitor mefenamic acid showed a 20% exposure increase, the effect of UGT1A1 inhibitors has not been assessed clinically. This modeling study describes a physiologically-based pharmacokinetic (PBPK) approach to complement the clinical DDI liability assessment and support prescription labeling. A PBPK model of vericiguat was developed based on invitro and clinical data, verified against data from the mefenamic acid DDI study, and applied to assess the UGT1A1 DDI liability by running an in silico DDI study with the UGT1A1 inhibitor atazanavir. A minor effect with an area under the plasma concentration-time curve (AUC) ratio of 1.12 and a peak plasma concentration ratio of 1.04 was predicted, which indicates that there is no clinically relevant DDI interaction anticipated. Additionally, the effect of potential genetic polymorphisms of UGT1A1 and UGT1A9 was evaluated, which showed that an average modest increase of up to 1.7-fold in AUC may be expected in the case of concomitantly reduced UGT1A1 and UGT1A9 activity for subpopulations expressing non-wild-type variants for both isoforms. This study is a first cornerstone to qualify the PK-Sim platform for use of UGT-mediated DDI predictions, including PBPK models of perpetrators, such as mefenamic acid and atazanavir, and sensitive UGT substrates, such as dapagliflozin and raltegravir.

Distribution pattern of UGT1A6 and UGT2B7 gene polymorphism and its impact on the pharmacokinetics of valproic acid and carbamazepine: Prospective genetic association study conducted in Pakistani patients with epilepsy

BackgroundEthnic variation is one of the important factors in clinical practice that may affect the pharmacokinetics of drugs. The present study aims to determine the distribution pattern of UGT1A6 and UGT2B7 gene polymorphism and its possible impact on the metabolism of valproic acid (VPA) and carbamazepine (CBZ) in patients with epilepsy from Khyber Pakhtunkhwa region of Pakistan. Methods: After the enrollment of targeted patients, blood was collected for genotype analysis through Sanger sequencing. Plasma concentrations of VPA and CBZ were determined by reversed-phase high-performance liquid chromatography (HPLC) at the follow-up visit of third month from the initiation of therapy. The drug plasma levels were correlated with different genotypes of UGT1A6 and UGT2B7 to determine the impact of genetic polymorphism on the drug metabolism. Results: Of the total 178 epileptic patients, 120 subjects were prescribed VPA monotherapy while 58 subjects were given CBZ monotherapy. The mean age of the subjects was recorded as 26.1 ± 13.5 years with a predominance of the male gender. Generalized tonic-clonic (GTC) was the most prevalent type of seizure (82%) followed by partial seizure. Genotype analysis revealed that the frequency of homozygous and heterozygous variants of the targeted UGT genes were exceptionally high in the Khyber Pakhtunkhwa population compared to the ethnic groups of other countries. In UGT1A6-A552C and UGT1A6-A541G, AC and AG were the most prevalent genotypes with respective frequencies of 43.2% and 41.1% whereas, in UGT2B7-T161C and UGT2B7-G211T, TC and GG were the most prevalent genotypes with respective frequencies of 42.7% and 99.4%. In the VPA-treated group, the homozygous and heterozygous variants of UGT1A6-A552C and UGT1A6-A541G were significantly associated with lower drug plasma concentrations (p < 0.05). However, none of the genotypes of UGT2B7-T161C revealed any significant association with VPA plasma concentration (p greater than 0.05). In the CBZ-treated group, UGT gene polymorphisms were not recognized to cause alteration in the drug plasma concentrations (p greater than 0.05). Conclusion: The genetic polymorphisms of UGT1A6, but not UGT2B7 significantly affected the plasma levels of valproic acid. The chosen SNPs did not reveal a role in determining the plasma levels of carbamazepine.

Updated results of the phase 1 I-FLOAT trial: Safety and efficacy of combining genotype-guided irinotecan with 5FU, leucovorin, oxaliplatin and docetaxel (gFOLFOXIRITAX) in advanced upper GI cancers.

e16038 Background: 5FU, Oxaliplatin (ox), irinotecan (iri) and docetaxel (tax) are each active in upper GI cancers; however, combination of all 4 agents (FOLFOXIRITAX) has not been studied. UGT1A1 polymorphisms may predispose to Iri toxicity. We sought to determine the maximum tolerated dose (MTD) in the 1st month of therapy (tx) among each of the low (L), intermediate (I) and high (H) risk UGT1A1 genotype (UGT) groups. We report the updated results of the I-FLOAT trial. Methods: Previously untx’d advanced upper GI cancer patients (pts) with ECOG PS 0/1 received gFOLFOXIRITAX (+ trastuzumab if HER2+) with pegfilgrastim. 5FU 2400mg/m2 over 46 hrs, LV 400mg/m2, Ox 85mg/m2, and Tax 25mg/m2 were given IV Q14 days. UGT-L, I, and H risk groups received starting Iri dose levels (DL1) of 120, 105 and 45mg/m2, respectively; Iri doses were escalated in each UGT group by 15mg/m2 increments and Tax to DL2 of 37.5mg/m2 using a I3+3 novel design (Liu &amp; Ji. J Biopharm Stat 2020). Other endpoints included overall safety (thru up to 8 cycles before maintenance 5FU +/- Iri/tras), ORR (RECIST1.1) &amp; ctDNA response (&gt;50% decrease in highest MAF) by G360 (Guardant Health). Results: From 6/30/2020-1/1/2023, 27 pts (11F, 16M) enrolled: median age 51 (range 21-76); 9 ECOG PS 1, UGT-L:I:H with 6:18:3 pts; 12 esophageal, 6 gastric, 8 pancreatic, and 1 bile duct cancer; 3 pts HER2+; 22 metastatic, 5 locally advanced unresectable. The median (range) of albumin and neutrophil-to-lymphocyte ratio (NLR) were 3.9 mg/dL (3.2-4.7) and 4.06 (1.89-27.6), respectively; 81% (22/27) of pts had a NLR &gt; 2.88, a poor prognostic marker. Dose limiting toxicities (DLTs) were seen in 5 pts: one G3 diarrhea (UGT-H, DL1/DL1 Iri/Tax), two G3 sepsis not neutropenic (one UGT-I, DL2/DL2 Iri/Tax; and one UGT-I, DL3/DL1 Iri/Tax), one G3 fatigue (UGT-I DL2/DL2 Iri/Tax) and one G3 diarrhea and neutropenic fever (UGT-L DL4/DL1 Iri/Tax). MTD has not been reached in any UGT TAX DL1 cohorts to date; currently enrolling UGT-H Iri/Tax DL1/DL1, UGT-I DL4/DL1, &amp; UGT-L DL4/DL1. The most frequent any Gr tx related toxicities: diarrhea (78%), fatigue (74%), nausea (70%), neuropathy (67%), anorexia (52%), elevated LFT (48%), anemia (37%), vomiting (37%). Of evaluable pts across all cohorts, PR/CR was seen in 18/22 (82%) patients, with 2 (9%) SD and 2 (9%) PD for a disease control rate of 91%. Of evaluable pts, best ctDNA response was seen in 12/13 (92%). Conclusions: gFOLFOXIRITAX continues to demonstrate tolerability at initial DLs of Iri/Tax. Efficacy is promising and could be an aggressive approach in upper GI cancers with high relapse risk in curative-intent settings. Clinical trial information: NCT04361708 .