Reader TTS

ABSTRACT BACKGROUND: Pazopanib has shown clinical activity against multiple tumour types and is generally well tolerated. However, isolated elevations in transaminases and bilirubin have

been observed. This study examined polymorphisms in molecules involved in pharmacokinetic and pharmacodynamic pathways of pazopanib and their association with hepatic dysfunction. METHODS:

Twenty-eight polymorphisms in 11 genes were evaluated in pazopanib-treated renal cell carcinoma patients. An exploratory analysis was conducted in 116 patients from a phase II study; a

replication study was conducted in 130 patients from a phase III study. RESULTS: No polymorphisms were associated with alanine aminotransferase elevation. The Gilbert's

_uridine-diphosphoglucuronate glucuronosyltransferase_ 1A1 (_UGT1A1_) TA-repeat polymorphism was significantly associated with pazopanib-induced hyperbilirubinemia in the phase II study.

This association was replicated in the phase III study (_P_<0.01). Patients with TA6/TA6, TA6/TA7, and TA7/TA7 genotypes experienced median bilirubin increases of 0.31, 0.37, and 0.71 ×

upper limit of the normal range (ULN), respectively. Of the 38 patients with hyperbilirubinemia (⩾1.5 × ULN), 32 (84%) were either TA7 homozygotes (_n_=18) or TA7 heterozygotes (_n_=14). For

TA7 homozygotes, the odds ratio (95% CI) for developing hyperbilirubinemia was 13.1 (5.3–32.2) compared with other genotypes. CONCLUSIONS: The _UGT1A1_ polymorphism is frequently associated

with pazopanib-induced hyperbilirubinemia. These data suggest that some instances of isolated hyperbilirubinemia in pazopanib-treated patients are benign manifestations of Gilbert's

syndrome, thus supporting continuation of pazopanib monotherapy in this setting. SIMILAR CONTENT BEING VIEWED BY OTHERS DUTCH PHARMACOGENETICS WORKING GROUP (DPWG) GUIDELINE FOR THE

GENE–DRUG INTERACTION BETWEEN _UGT1A1_ AND IRINOTECAN Article 28 November 2022 EFFECT OF DRUG METABOLIZING ENZYMES AND TRANSPORTERS IN THAI COLORECTAL CANCER PATIENTS TREATED WITH

IRINOTECAN-BASED CHEMOTHERAPY Article Open access 10 August 2020 INTEGRATION OF DNA SEQUENCING WITH POPULATION PHARMACOKINETICS TO IMPROVE THE PREDICTION OF IRINOTECAN EXPOSURE IN CANCER

PATIENTS Article 26 October 2021 MAIN Pazopanib (Votrient, GlaxoSmithKline), recently approved by the United States Food and Drug Administration (FDA) for the treatment of patients with

advanced renal cell carcinoma (RCC) (GlaxoSmithKline, 2009), is an oral angiogenesis inhibitor targeting vascular endothelial growth factor receptors-1, -2, and -3; platelet-derived growth

factor receptors-_α_ and -_β_; and the stem cell factor receptor, c-kit (Sonpavde and Hutson, 2007). It is currently under clinical development for the treatment of multiple tumour types

(Altorki et al, 2008; Friedlander et al, 2008; Sleijfer et al, 2009; Taylor et al, 2009; Sternberg et al, 2010). Clinical meaningful efficacy was observed in pazopanib-treated patients with

RCC (Hutson et al, 2010; Sternberg et al, 2010). The safety profile of pazopanib was generally acceptable and tolerable. The most common adverse events were diarrhoea, hypertension, hair

colour changes, nausea, anorexia, and vomiting (Sternberg et al, 2010). Elevations of liver transaminases were the most common treatment-emergent laboratory abnormalities (Sternberg et al,

2010). Elevations in alanine aminotransferase (ALT) >3 × upper limit of the normal range (ULN) occurred in 18% of the pazopanib-treated RCC patients. Isolated elevations of total

bilirubin (TBL) >1.5 × ULN were seen in 17% of pazopanib-treated RCC patients. Elevations in liver enzymes were generally asymptomatic and reversible and concurrent elevations in both ALT

and bilirubin were rare. As the aetiology and mechanism of liver enzyme elevation in pazopanib-treated patients remain unknown, recommended management guideliness are based on analysis of

data from clinical trials. Treatment-associated elevations in transaminases and bilirubin have been reported with other tyrosine kinase inhibitors including sunitinib, lapatinib, and

erlotinib (Motzer et al, 2007; Loriot et al, 2008; Ryan et al, 2008), and the incidence varies with agent. It is possible that these treatment-associated elevations in liver enzymes observed

with tyrosine kinase inhibitors reflect overlapping on-target and off-target class effects; however, specific mechanisms remain to be elucidated. Abnormalities in clinical liver chemistry

measurements are important safety signals for liver injury and may lead to treatment discontinuation, thereby compromising the potential treatment benefit to the patient. Understanding the

underlying mechanisms of liver chemistry abnormalities may enable better interpretation and clinical management of these safety signals, and in appropriate circumstances, allow patients to

benefit from continued anticancer treatment. We sought to identify genetic markers in selected candidate genes involved in pazopanib metabolism and pharmacodynamics that may predict risk of

ALT and/or bilirubin elevation on treatment. Pazopanib is a substrate for p-glycoprotein and breast cancer-resistant protein, an inhibitor of the human uptake transporter OATP1B1, and an

inhibitor of uridine-diphosphoglucuronate glucuronosyltransferase 1A1 (UGT1A1). It is predominately metabolised by CYP3A4 with a minor contribution from CYP2C8 and CYP1A2. Functional

polymorphisms in these genes as well as in pazopanib target genes were evaluated using data from two clinical studies that evaluated the efficacy and safety of pazopanib in patients with

advanced metastatic RCC (Hutson et al, 2010; Sternberg et al, 2010). MATERIALS AND METHODS The protocol and informed consent forms were reviewed and approved by Institutional Review

Boards/Independent Ethics Committees according to local guidelines. Clinical studies were conducted in accordance with the Declaration of Helsinki. Written informed consent for participation

in the clinical studies was obtained from all patients, and an additional informed consent for pharmacogenetics (PGx) research was obtained for participation in the genetic study. PATIENTS

The phase II RCC study (VEG102616, Study 1) had 225 participants (Hutson et al, 2010) and the phase III RCC study (VEG105192, Study 2) had 435 participants (Sternberg et al, 2010). All

patients from Study 1 and 290 patients from Study 2 received pazopanib (800 mg daily); the remaining 145 patients in Study 2 were randomised to the placebo arm. To minimise the effect of

genetic heterogeneity among ethnic groups on the statistical analyses, the present PGx analyses were performed using the self-reported ‘white’ patients of European heritage, which

represented the largest subgroup in each of the clinical studies. There were 156 self-reported white patients in Study 1, of whom 116 provided written informed consent for genetic research

and had sufficient DNA for genotyping. There were 204 self-reported white patients in Study 2 who received pazopanib, of whom 130 provided written informed consent for genetic research and

had sufficient DNA for genotyping. The present PGx analysis population, therefore, consisted of data from the 116 white patients from Study 1 and 130 white patients from Study 2 who received

pazopanib and had genotypic data for at least one of the genetic markers evaluated (Figure 1). LIVER CHEMISTRY MEASUREMENTS Alanine aminotransferase and bilirubin measurements were

performed by local institutional laboratories. Both ALT and TBL values were converted to ULN by dividing the laboratory value by the institutional ULN. None of the patients from either study

had a baseline ALT level >3 × ULN or baseline bilirubin level >1.5 × ULN. GENETIC POLYMORPHISMS AND GENOTYPING Twenty-eight genetic polymorphisms in 11 genes involved in the

pharmacokinetics and pharmacodynamics of pazopanib were selected (Table 1). The selection was based on reported associations or assumed functional changes of the polymorphisms to the

expression or activity of the proteins. The DNA was extracted from blood using the Qiagen (Valencia, CA, USA) QiAmp DNA Blood kit. The _UGT1A1_ TA-repeat polymorphism (rs8175347) was

genotyped using the FDA-approved Third Wave Invader Assay, which called two alleles: the TA6 (*1) allele and the TA7 (*28) allele. In the rare instance when a patient had a TA-repeat number

that was not 6 or 7 (<1%), the genotype call for that patient was treated as missing data. The remaining polymorphisms were genotyped using Illumina (San Diego, CA, USA) GoldenGate

platform (Fan et al, 2003), a single base chain extension assay modified by GlaxoSmithKline (Research Triangle Park, NC, USA) (Taylor et al, 2001), TaqMan SNP Genotyping assays (Applied

Biosystems, Foster City, CA, USA; Livak et al, 1995), or sequencing. _IN VITRO_ UGT1A1 INHIBITION The activity of human UGT1A1 was measured in the absence and presence of pazopanib. Human

UGT1A1 Supersomes (BD Gentest, BD Biosciences, San Jose, CA, USA) were preincubated in duplicate for 5 min at 37°C in the presence of the pore-former alamethicin, the UGT1A1 substrate

7-hydroxy-4-(trifluoromethyl) coumarin (HFC), and pazopanib concentrations ranging from 0 to 250 _μ_ M. At the end of preincubation, the enzymatic reaction was initiated by adding the

cofactor uridine 5′-diphosphoglucuronic acid (UDPGA). The reaction was terminated after an additional 10 min by adding acetonitrile/acetic acid (94/6 [v/v]), followed by centrifugation to

sediment-precipitated protein. The production of the HFC metabolite 4-trifluoromethylumbelliferyl glucuronide (HFC-gluc) in each supernatant was quantified by HPLC-UV, and the half-maximal

inhibitory concentration (IC50) value for inhibition of UGT1A1 activity was determined. Incubations without pazopanib were performed in the presence and absence of UDPGA to confirm

production of the UDPGA-dependent glucuronide metabolite HFC-gluc. Incubations without probe substrate (HFC) were performed to determine any potential assay interference by pazopanib. The

IC50 of curcumin, a positive-control inhibitor, was determined in parallel incubations in which pazopanib was replaced with appropriate concentrations of curcumin. _IN VITRO_ OATP1B1

INHIBITION Inhibition of uptake of the OATP1B1 probe substrate [3H]-estradiol 17_β_-D-glucuronide ([3H]-EG) by pazopanib was measured using a stably transfected CHO cell line. The

CHO-OATP1B1 cells were cultured to confluency, trypsinised, and seeded into 24-well assay plates (Becton, Dickinson and Company, Franklin Lakes, NJ, USA) at a density of 70 000 cells cm–2 in

Dulbecco's Modified Eagle Medium (DMEM) with GlutaMAX, 10% (v/v) foetal bovine serum, 0.5% (v/v) penicillin/streptomycin 10 000 units ml–1, 0.1% (v/v) L-proline 50 mg ml–1, and 0.7%

(v/v) geneticin 50 mg ml–1. The cell monolayers were used 2 days after seeding and induced for at least 24 h before use with the addition of DMEM containing sodium butyrate (final

concentration, 5 mM). In the inhibition studies, CHO-OATP1B1 monolayers were preincubated (37°C) for 15–30 min in 1 ml of Dulbecco's Phosphate-Buffered Saline (DPBS) with the

appropriate concentration of pazopanib. Triplicate wells were used for each concentration of test compound. After removal of preincubation solution, 400 _μ_l of DPBS containing the

radiolabelled probe substrate and the appropriate concentrations of pazopanib was added to the wells and the cells were incubated at 37°C for 5 min. The solution was then removed and the

wells rinsed rapidly three times using 800 _μ_l cold (4°C) DPBS before solubilisation with 500 _μ_l of 1% (v/v) Triton X-100. Total radioactivity was determined by scintillation counting.

STATISTICAL ANALYSIS The data were analysed both as continuous variables in a quantitative trait analysis (QTA) and as discrete values according to predefined thresholds in a case–control

analysis. All analyses were performed in SAS version 9.1.3 (SAS Institute, Cary, NC, USA). The QTA was performed using an analysis of covariance model to assess the effect of genetic factors

on baseline, maximum on-treatment, and change from baseline (delta) values for ALT and TBL. In the analyses of maximum on-treatment ALT and maximum on-treatment TBL, baseline was included

in the model as a covariate. A log10-transformation was performed on the ALT and TBL values and a rank transformation was performed on the change-from-baseline values to correct for skewness

of the data. For case–control association analysis, a patient was defined as an ALT ‘case’ if one or more ALT measurements were ⩾3 × ULN during dosing with pazopanib. A patient was

classified as an ALT ‘control’ if all ALT measurements were within the normal range (⩽1 × ULN). A patient was defined as a TBL ‘case’ if one or more TBL measurements were ⩾1.5 × ULN during

exposure to pazopanib, and a TBL ‘control’ if all measurements were within the normal range (⩽1 × ULN). The effect of a genetic polymorphism on ALT or TBL was assessed using Fisher's

exact test. The initial exploratory analysis was performed using data from the phase II study (Study 1; VEG102616) and the replication analysis was conducted using data from the phase III

study (Study 2; VEG105192). Correction for multiple tests was not performed. Instead, a threshold of _P_<0.01 was used to determine statistical significance in each study. A marker was

‘replicated’ when it was identified to be statistically significant in Study 1 followed by replication in Study 2. For replicated markers, a combined analysis using data from both studies

was carried out to evaluate the overall effect. RESULTS Demographic and baseline characteristics for patients included in the present PGx investigation from Study 1 and Study 2 are shown in

Table 2. None of the patients included in the PGx analysis had a baseline ALT level >3 × ULN or baseline bilirubin level >1.5 × ULN. Exploratory analyses of the effects of the 28

genetic polymorphisms on maximum ALT and bilirubin were first examined using data from Study 1. None of the markers were significantly associated with maximum ALT (_P_<0.01), and three

markers in the _UGT1A1_ and _CYP1A2_ loci were significantly associated with maximum bilirubin (_P_<0.01). The markers from the _UGT1A1_ locus were the TA-repeat polymorphism

(_UGT1A1_*28) and the –3279T/G polymorphism (_UGT1A1_*60), and the marker from the _CYP1A2_ locus was the –163C/A polymorphism (Table 1). Replication analyses of the three significant TBL

markers identified in Study 1 were performed using data from Study 2. Only the TA-repeat polymorphism from the _UGT1A1_ gene was replicated (_P_<0.01). This polymorphism was not

associated with maximum ALT measurements in either study. Data from both studies were subsequently combined to determine the overall effect of the _UGT1A1_ TA-repeat polymorphism on

bilirubin levels. Of the 246 patients included in this PGx analysis, data for bilirubin and the _UGT1A1_ TA-repeat marker were obtained for 236 patients (Figure 1). Of the remaining 10

patients, 5 had missing _UGT1A1_ genotype data and 5 had missing log10-transformed maximum or baseline TBL data. As expected, a significant association between the _UGT1A1_ TA-repeat

polymorphism and maximum bilirubin was observed (_P_=1.6 × 10−6 and _P_=1.8 × 10−8 for the QTA and case–control analysis, respectively). The median values of maximum bilirubin were 0.75 ×

ULN, 0.87 × ULN, and 1.40 × ULN for patients with the TA6/TA6, TA6/TA7, and TA7/TA7 genotypes, respectively. Moreover, this polymorphism was significantly associated with bilirubin increases

from baseline (delta) during pazopanib treatment (_P_=4.5 × 10−5). The median bilirubin increases were 0.31 × ULN, 0.37 × ULN, and 0.71 × ULN for pazopanib-treated patients with the

TA6/TA6, TA6/TA7, and TA7/TA7 genotypes, respectively. Thus, the median on-treatment bilirubin increase for TA7 homozygotes was 2.3-fold greater than the increase observed for the TA6

homozygotes (Figure 2). Compared with the TA6/TA6 and TA6/TA7 genotypes, the odds ratio (95% confidence interval), positive predictive value, and negative predictive value for TA7/TA7

genotype were 13.1 (5.3–32.2), 0.49, and 0.90, respectively. The incidence of hyperbilirubinemia was 49% (18 of 37) for patients with the TA7/TA7 genotypes and 12% (14 of 113) for patients

with the TA6/TA7 genotypes (Figure 3). In contrast, pazopanib-related incidence of hyperbilirubinemia was only 7% (6 of 86) for patients with the TA6/TA6 genotype. Of the 38 cases of TBL

elevation, 32 patients (84%) were either TA7 homozygotes (_n_=18, 47%) or TA7 heterozygotes (_n_=14, 37%). The ability of pazopanib to inhibit the two major determinants of serum bilirubin

levels, UGT1A1 and OATP1B1, was measured. Pazopanib was shown to be a potent inhibitor of UGT1A1 as well as OATP1B1, with IC50 of 1.2 and 0.79 _μ_ M, respectively (Figure 4). DISCUSSION This

study shows that both maximum on-treatment bilirubin concentration and bilirubin increase from baseline were strongly associated with the _UGT1A1_ TA-repeat polymorphism. None of the

genetic markers evaluated were predictive of ALT elevation. Bilirubin is metabolised by UGT1A1 for elimination. The _UGT1A1_ genetic variant TA7 is known to cause reduced expression of

UGT1A1 (Bosma et al, 1995), and the TA7/TA7 (*28/*28) genotype predisposes individuals to Gilbert's syndrome, a benign form of episodic jaundice (Bosma et al, 1995; Raijmakers et al,

2000). This _UGT1A1_ TA-repeat polymorphism has also been reported to be associated with hyperbilirubinemia induced by several drugs, such as tranilast, nilotinib, and indinavir (Zucker et

al, 2001; Danoff et al, 2004; Singer et al, 2007). Pazopanib is a potent inhibitor of UGT1A1 activity _in vitro_, with an IC50 of 1.2 _μ_ M. Thus, this study suggests that pazopanib-induced

hyperbilirubinemia may be the result of inhibition of UGT1A1 activity combined with genetic defects of the _UGT1A1_ gene. This would presumably result in higher levels of unconjugated

hyperbilirubinemia, usually associated with a benign clinical course. It is possible that bilirubin elevation associated with other tyrosine kinase inhibitors such as sunitinib, lapatinib,

and erlotinib may also be related to _UGT1A1_ genotype. However, to our knowledge, data from genetic investigations for drug-induced hyperbilirubinemia for these compounds are not yet

available. We observed that 6 (16%) of the 38 patients who had isolated hyperbilirubinemia had the TA6/TA6 genotype, suggesting that additional factors may contribute to bilirubin elevation

in pazopanib-treated patients. Concurrent elevations of transaminases were not seen in these six patients. A recent genome-wide association study identified _OATP1B1_ (alternative symbol

_SLCO1B1_) as one of the top loci associated with bilirubin levels (Johnson et al, 2009). Genetic markers in the _OATP1B1_ gene were also evaluated in this study and were not found to be

associated with pazopanib-related bilirubin elevation. As pazopanib is also a potent inhibitor of OATP1B1 (_in vitro_), we cannot exclude the possibility that pazopanib-induced

hyperbilirubinemia may be the result of inhibition of both OATP1B1 and UGT1A1 activity combined with genetic defects of the _UGT1A1_ gene. The lack of association with genetic markers in the

_OATP1B1_ gene may stem from the fact that pazopanib inhibited hepatic uptake of bilirubin to the same level in both wild type and variant forms. Among the 246 patients evaluated in this

study, concurrent elevation of ALT and bilirubin was observed in one patient (0.4%). This patient was heterozygous (TA6/TA7) for the _UGT1A1_ TA-repeat polymorphism and had direct bilirubin

of 0.5 mg l–1, representing 22% of TBL (2.3 mg dl–1). Reduced UGT1A1 activity, both as a result of pazopanib inhibition of UGT1A1 and the genetic defect of the _UGT1A1_ gene, may have

contributed to the bilirubin elevation observed in this patient. Concurrent elevations in ALT and bilirubin levels after pazopanib treatment could indicate liver toxicity (Kaplowitz, 2006);

therefore, it is important to rule out this possibility to allow continued treatment. This is particularly important because continued anticancer treatment may allow for more favourable

clinical outcomes and should be feasible in patients with benign hyperbilirubinemia, as might be the case for most pazopanib-treated patients. It follows that, for each patient, the clinical

management of hepatotoxicity needs to be tailored according to the severity and impact of this adverse effect on the patient. In addition, the mechanisms involved in the observed elevation

in transaminases and bilirubin should also be considered. This study focused on data from trials evaluating pazopanib monotherapy in patients with RCC. The observed elevation in ALT or

bilirubin levels was not associated with liver metastasis for patients included in the present PGx analysis. The full implications of these findings for regimens combining pazopanib with

other agents are currently unknown. Clearly, it is important for clinicians to be aware of potential drug–drug interactions, particularly with compounds known to be metabolised and

eliminated predominantly through the UGT1A1 pathway. Therefore, concomitant administration of pazopanib and UGT1A1 substrates that have narrow therapeutic index should be undertaken with

caution. Pazopanib itself is not known to be subject to significant glucuronidation by UGT1A1. It is, therefore, unlikely that defective UGT1A1 would have a direct impact on the exposure of

pazopanib and, therefore, exposure-related toxicities. The practical implication of our finding is for clinicians to recognise that isolated hyperbilirubinemia in pazopanib-treated patients,

after exclusion of other causes such as haemolysis, seems to have a benign aetiology. Given the life-threatening nature of cancer and the benign clinical course of unconjugated

hyperbilirubinemia, the data do not call for population-based prospective _UGT1A1_ screening to exclude patients from pazopanib monotherapy. Bilirubin fractionation should be conducted in

patients who develop hyperbilirubinemia during pazopanib treatment, which could distinguish unconjugated hyperbilirubinemia from conjugated hyperbilirubinemia. The latter would require

further investigation. This may help to elucidate the nature of the bilirubin elevation and might enable differentiation of the risk of progression of drug-induced liver injury. A limitation

of this study is the lack of bilirubin fractionation data to allow full assessment between the _UGT1A1_ polymorphism and unconjugated bilirubin levels. REFERENCES * Aklillu E, Carrillo JA,

Makonnen E, Hellman K, Pitarque M, Bertilsson L, Ingelman-Sundberg M (2003) Genetic polymorphism of CYP1A2 in Ethiopians affecting induction and expression: characterization of novel

haplotypes with single-nucleotide polymorphisms in intron 1. _Mol Pharmacol_ 64 (3): 659–669 Article  CAS  Google Scholar  * Altorki N, Heymach J, Guarino M, Lee P, Felip E, Bauer T, Swann

S, Roychowdhury D, Ottesen LH, Yankelevitz D (2008) Phase II study of Pazopanib (GW786034) given preoperatively in stage i-ii non-small cell lung cancer (NSCLC): a proof-of-concept study.

_Ann Oncol_ 19 (suppl 8): viii89 Google Scholar  * Aono S, Yamada Y, Keino H, Hanada N, Nakagawa T, Sasaoka Y, Yazawa T, Sato H, Koiwai O (1993) Identification of defect in the genes for

bilirubin UDP-glucuronosyl-transferase in a patient with Crigler-Najjar syndrome type II. _Biochem Biophys Res Commun_ 197 (3): 1239–1244 Article  CAS  Google Scholar  * Bahadur N, Leathart

JB, Mutch E, Steimel-Crespi D, Dunn SA, Gilissen R, Houdt JV, Hendrickx J, Mannens G, Bohets H, Williams FM, Armstrong M, Crespi CL, Daly AK (2002) CYP2C8 polymorphisms in Caucasians and

their relationship with paclitaxel 6alpha-hydroxylase activity in human liver microsomes. _Biochem Pharmacol_ 64 (11): 1579–1589 Article  CAS  Google Scholar  * Bosma PJ, Chowdhury JR,

Bakker C, Gantla S, de Boer A, Oostra BA, Lindhout D, Tytgat GN, Jansen PL, Oude Elferink RP, Chowdhury NR (1995) The genetic basis of the reduced expression of bilirubin

UDP-glucuronosyltransferase 1 in Gilbert's syndrome. _N Engl J Med_ 333 (18): 1171–1175 Article  CAS  Google Scholar  * Dai D, Zeldin DC, Blaisdell JA, Chanas B, Coulter SJ, Ghanayem

BI, Goldstein JA (2001) Polymorphisms in human CYP2C8 decrease metabolism of the anticancer drug paclitaxel and arachidonic acid. _Pharmacogenetics_ 11 (7): 597–607 Article  CAS  Google

Scholar  * Danoff TM, Campbell DA, McCarthy LC, Lewis KF, Repasch MH, Saunders AM, Spurr NK, Purvis IJ, Roses AD, Xu CF (2004) A Gilbert's syndrome UGT1A1 variant confers susceptibility

to tranilast-induced hyperbilirubinemia. _Pharmacogenomics J_ 4 (1): 49–53 Article  CAS  Google Scholar  * Fan JB, Oliphant A, Shen R, Kermani BG, Garcia F, Gunderson KL, Hansen M, Steemers

F, Butler SL, Deloukas P, Galver L, Hunt S, McBride C, Bibikova M, Rubano T, Chen J, Wickham E, Doucet D, Chang W, Campbell D, Zhang B, Kruglyak S, Bentley D, Haas J, Rigault P, Zhou L,

Stuelpnagel J, Chee MS (2003) Highly parallel SNP genotyping. _Cold Spring Harb Symp Quant Biol_ 68: 69–78 Article  CAS  Google Scholar  * Friedlander M, Hancock KC, Benigno B, Rischin D,

Messing M, Stringer CA, Hodge JP, Ma B, Matthys G, Lager JJ (2008) Pazopanib (GW786034) is active in women with advanced epithelial ovarian, fallopian tube, and peritoneal cancers: results

of a phase II study. _Ann Oncol_ 19 (suppl 8): viii211 Google Scholar  * GlaxoSmithKline (2009) FDA approves GlaxoSmithKline's Votrient for advanced renal cell cancer.

www.gsk.com/media/pressreleases/2009/2009_pressrelease_10113.htm * Han XM, Ouyang DS, Chen XP, Shu Y, Jiang CH, Tan ZR, Zhou HH (2002) Inducibility of CYP1A2 by omeprazole _in vivo_ related

to the genetic polymorphism of CYP1A2. _Br J Clin Pharmacol_ 54 (5): 540–543 Article  CAS  Google Scholar  * Hutson TE, Davis ID, Machiels JP, De Souza PL, Rottey S, Hong B, Epstein RJ,

Baker KL, McCann L, Crofts T, Liu Y, Pandite L, Figlin RA (2010) Efficacy and safety of pazopanib in patients with metastatic renal cell carcinoma. _J Clin Oncol_ 28 (3): 475–480 Article 

CAS  Google Scholar  * Johnson AD, Kavousi M, Smith AV, Chen MH, Dehghan A, Aspelund T, Lin JP, van Duijn CM, Harris TB, Cupples LA, Uitterlinden AG, Launer L, Hofman A, Rivadeneira F,

Stricker B, Yang Q, O′Donnell CJ, Gudnason V, Witteman JC (2009) Genome-wide association meta-analysis for total serum bilirubin levels. _Hum Mol Genet_ 18 (14): 2700–2710 Article  CAS 

Google Scholar  * Jounaidi Y, Hyrailles V, Gervot L, Maurel P (1996) Detection of CYP3A5 allelic variant: a candidate for the polymorphic expression of the protein? _Biochem Biophys Res

Commun_ 221 (2): 466–470 Article  CAS  Google Scholar  * Kaplowitz N (2006) Rules and laws of drug hepatotoxicity. _Pharmacoepidemiol Drug Saf_ 15 (4): 231–233 Article  CAS  Google Scholar 

* Kerb R (2006) Implications of genetic polymorphisms in drug transporters for pharmacotherapy. _Cancer Lett_ 234 (1): 4–33 Article  CAS  Google Scholar  * Livak KJ, Marmaro J, Todd JA

(1995) Towards fully automated genome-wide polymorphism screening. _Nat Genet_ 9 (4): 341–342 Article  CAS  Google Scholar  * Loriot Y, Boudou-Rouquette P, Billemont B, Ropert S, Goldwasser

F (2008) Acute exacerbation of hemorrhagic rectocolitis during antiangiogenic therapy with sunitinib and sorafenib. _Ann Oncol_ 19 (11): 1975 Article  CAS  Google Scholar  * Mizuarai S,

Aozasa N, Kotani H (2004) Single nucleotide polymorphisms result in impaired membrane localization and reduced atpase activity in multidrug transporter ABCG2. _Int J Cancer_ 109 (2): 238–246

Article  CAS  Google Scholar  * Morisaki K, Robey RW, Ozvegy-Laczka C, Honjo Y, Polgar O, Steadman K, Sarkadi B, Bates SE (2005) Single nucleotide polymorphisms modify the transporter

activity of ABCG2. _Cancer Chemother Pharmacol_ 56 (2): 161–172 Article  CAS  Google Scholar  * Motzer RJ, Hutson TE, Tomczak P, Michaelson MD, Bukowski RM, Rixe O, Oudard S, Negrier S,

Szczylik C, Kim ST, Chen I, Bycott PW, Baum CM, Figlin RA (2007) Sunitinib versus interferon alfa in metastatic renal-cell carcinoma. _N Engl J Med_ 356 (2): 115–124 Article  CAS  Google

Scholar  * Nozawa T, Nakajima M, Tamai I, Noda K, Nezu J, Sai Y, Tsuji A, Yokoi T (2002) Genetic polymorphisms of human organic anion transporters OATP-C (SLC21A6) and OATP-B (SLC21A9):

allele frequencies in the Japanese population and functional analysis. _J Pharmacol Exp Ther_ 302 (2): 804–813 Article  CAS  Google Scholar  * Raijmakers MT, Jansen PL, Steegers EA, Peters

WH (2000) Association of human liver bilirubin UDP-glucuronyltransferase activity with a polymorphism in the promoter region of the UGT1A1 gene. _J Hepatol_ 33 (3): 348–351 Article  CAS 

Google Scholar  * Rodriguez-Antona C, Sayi JG, Gustafsson LL, Bertilsson L, Ingelman-Sundberg M (2005) Phenotype-genotype variability in the human CYP3A locus as assessed by the probe drug

quinine and analyses of variant CYP3A4 alleles. _Biochem Biophys Res Commun_ 338 (1): 299–305 Article  CAS  Google Scholar  * Ryan Q, Ibrahim A, Cohen MH, Johnson J, Ko CW, Sridhara R,

Justice R, Pazdur R (2008) FDA drug approval summary: lapatinib in combination with capecitabine for previously treated metastatic breast cancer that overexpresses HER-2. _Oncologist_ 13

(10): 1114–1119 Article  CAS  Google Scholar  * Schneider BP, Wang M, Radovich M, Sledge GW, Badve S, Thor A, Flockhart DA, Hancock B, Davidson N, Gralow J, Dickler M, Perez EA, Cobleigh M,

Shenkier T, Edgerton S, Miller KD (2008) Association of vascular endothelial growth factor and vascular endothelial growth factor receptor-2 genetic polymorphisms with outcome in a trial of

paclitaxel compared with paclitaxel plus bevacizumab in advanced breast cancer: ECOG 2100. _J Clin Oncol_ 26 (28): 4672–4678 Article  CAS  Google Scholar  * Singer JB, Shou Y, Giles F,

Kantarjian HM, Hsu Y, Robeva AS, Rae P, Weitzman A, Meyer JM, Dugan M, Ottmann OG (2007) UGT1A1 promoter polymorphism increases risk of nilotinib-induced hyperbilirubinemia. _Leukemia_ 21

(11): 2311–2315 Article  CAS  Google Scholar  * Sleijfer S, Ray-Coquard I, Papai Z, Le Cesne A, Scurr M, Schoffski P, Collin F, Pandite L, Marreaud S, De Brauwer A, van Glabbeke M, Verweij

J, Blay JY (2009) Pazopanib, a multikinase angiogenesis inhibitor, in patients with relapsed or refractory advanced soft tissue sarcoma: a phase II study from the European organisation for

research and treatment of cancer-soft tissue and bone sarcoma group (EORTC study 62043). _J Clin Oncol_ 27 (19): 3126–3132 Article  CAS  Google Scholar  * Sonpavde G, Hutson TE (2007)

Pazopanib: a novel multitargeted tyrosine kinase inhibitor. _Curr Oncol Rep_ 9 (2): 115–119 Article  CAS  Google Scholar  * Sternberg CN, Davis ID, Mardiak J, Szczylik C, Lee ES, Wagstaff J,

Barrios CH, Salman P, Gladkov OA, Kavina A, Zarba JJ, Chen M, McCann L, Pandite L, Roychowdhury D, Hawkins RE (2010) Pazopanib in locally advanced and/or metastatic renal cell carcinoma:

results of a randomized phase III trial. _J Clin Oncol_ 28 (6): 1061–1068 Article  CAS  Google Scholar  * Sugatani J, Yamakawa K, Yoshinari K, Machida T, Takagi H, Mori M, Kakizaki S,

Sueyoshi T, Negishi M, Miwa M (2002) Identification of a defect in the UGT1A1 gene promoter and its association with hyperbilirubinemia. _Biochem Biophys Res Commun_ 292 (2): 492–497 Article

  CAS  Google Scholar  * Tanimoto K, Yoshiga K, Eguchi H, Kaneyasu M, Ukon K, Kumazaki T, Oue N, Yasui W, Imai K, Nakachi K, Poellinger L, Nishiyama M (2003) Hypoxia-inducible factor-1alpha

polymorphisms associated with enhanced transactivation capacity, implying clinical significance. _Carcinogenesis_ 24 (11): 1779–1783 Article  CAS  Google Scholar  * Taylor JD, Briley D,

Nguyen Q, Long K, Iannone MA, Li MS, Ye F, Afshari A, Lai E, Wagner M, Chen J, Weiner MP (2001) Flow cytometric platform for high-throughput single nucleotide polymorphism analysis.

_Biotechniques_ 30 (3): 661–666, 668–669 Article  CAS  Google Scholar  * Taylor SK, Chia S, Dent S, Clemons M, Grenci P, Wang L, Oza AM, Ivy P, Pritchard K, Leighl N (2009) A phase II study

of GW786034 (pazopanib) in patients with recurrent or metastatic invasive breast carcinoma: results after completion of stage I: a trial of the Princess Margaret Hospital Phase II

Consortium. _J Clin Oncol_ 27 (15s): abstract 1133 * Wong M, Balleine RL, Collins M, Liddle C, Clarke CL, Gurney H (2004) CYP3A5 genotype and midazolam clearance in Australian patients

receiving chemotherapy. _Clin Pharmacol Ther_ 75 (6): 529–538 Article  CAS  Google Scholar  * Zucker SD, Qin X, Rouster SD, Yu F, Green RM, Keshavan P, Feinberg J, Sherman KE (2001)

Mechanism of indinavir-induced hyperbilirubinemia. _Proc Natl Acad Sci USA_ 98 (22): 12671–12676 Article  CAS  Google Scholar  Download references ACKNOWLEDGEMENTS We thank the investigators

and their patients who made this study possible. We acknowledge Leigh Ragone, Morlisa Dixon, Bo Zheng, Nan Bing, and Keith Nangle for their excellent technical support. We thank Melissa

Stutts, Vicki Goodman, Theresa Bryant, and Chris Abissi for their contribution in evaluating patients with potential hepatotoxicity; Lauren McCann and Shawn Liu for discussion of the

laboratory liver chemistry data. We are grateful to Rafael Amado, Pamela StJean, Matthew Nelson, Anne Marie Martin, and Howard Ball, and the GSK hepatotoxicity board, in particular Christine

Hunt and Beena Koshy, for their review and discussion of the data. Financial support for this study and medical editorial assistance was provided by GlaxoSmithKline Pharmaceuticals,

Philadelphia, Pennsylvania. We thank Jerome Sah, PhD, ProEd Communications, Inc., for his medical editorial assistance with this manuscript. AUTHOR INFORMATION AUTHORS AND AFFILIATIONS *

Genetics Division, GlaxoSmithKline, Research and Development, New Frontiers Science Park (North), Room H30-2-060, Third Avenue, Harlow, Essex, CM19 5AW, UK C-F Xu, B H Reck, Z Xue, L Huang, 

V E Mooser, L R Cardon & C F Spraggs * GlaxoSmithKline, Oncology Research and Development, 5 Moore Drive, 17.2266B, Research Triangle Park, 27709, NC, USA K L Baker, M Chen & L

Pandite * GlaxoSmithKline, Drug Metabolism and Pharmacokinetics, 709 Swedeland Road, King of Prussia, 19403, PA, USA E P Chen & H E Ellens Authors * C-F Xu View author publications You

can also search for this author inPubMed Google Scholar * B H Reck View author publications You can also search for this author inPubMed Google Scholar * Z Xue View author publications You

can also search for this author inPubMed Google Scholar * L Huang View author publications You can also search for this author inPubMed Google Scholar * K L Baker View author publications

You can also search for this author inPubMed Google Scholar * M Chen View author publications You can also search for this author inPubMed Google Scholar * E P Chen View author publications

You can also search for this author inPubMed Google Scholar * H E Ellens View author publications You can also search for this author inPubMed Google Scholar * V E Mooser View author

publications You can also search for this author inPubMed Google Scholar * L R Cardon View author publications You can also search for this author inPubMed Google Scholar * C F Spraggs View

author publications You can also search for this author inPubMed Google Scholar * L Pandite View author publications You can also search for this author inPubMed Google Scholar CORRESPONDING

AUTHOR Correspondence to C-F Xu. RIGHTS AND PERMISSIONS This work is licensed under the Creative Commons Attribution-NonCommercial-Share Alike 3.0 License. To view a copy of this license,

visit http://creativecommons.org/licenses/by-nc-sa/3.0/ Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Xu, CF., Reck, B., Xue, Z. _et al._ Pazopanib-induced hyperbilirubinemia

is associated with Gilbert's syndrome _UGT1A1_ polymorphism. _Br J Cancer_ 102, 1371–1377 (2010). https://doi.org/10.1038/sj.bjc.6605653 Download citation * Received: 18 November 2009

* Revised: 11 March 2010 * Accepted: 18 March 2010 * Published: 13 April 2010 * Issue Date: 27 April 2010 * DOI: https://doi.org/10.1038/sj.bjc.6605653 SHARE THIS ARTICLE Anyone you share

the following link with will be able to read this content: Get shareable link Sorry, a shareable link is not currently available for this article. Copy to clipboard Provided by the Springer

Nature SharedIt content-sharing initiative KEYWORDS * alanine aminotransferase * bilirubin * pazopanib * pharmacogenetics * renal cell carcinoma * _UGT1A1_