Phase I study of irinotecan and doxifluridine for metastatic colorectal cancer focusing on the UGT1A1*28 polymorphism.
ABSTRACT Although individuals carrying the UGT1A1 allele *28 have an increased risk of severe toxicities associated with irinotecan, no phase I study has been conducted based on the polymorphism. This report presents the recommended doses of irinotecan for patients with the respective genotypes. Twenty-seven patients with advanced colorectal cancer were enrolled in this study, and the UGT1A1*28 polymorphism was genotyped before chemotherapy. One course of chemotherapy consisted of irinotecan infused once every 2 weeks at 70, 100, 120, and 150 mg/m(2) at dose levels 1, 2, 3, and 4, respectively, and doxifluridine was administered orally. This treatment continued for at least 12 weeks. The dose-limiting toxicity was determined as grade 3 hematological and non-hematological toxicities for the TA(6)/TA(6) (6/6) and TA(6)/TA(7) (6/7) genotypes. The pharmacokinetics of irinotecan, SN-38, and SN-38 glucuronide, was assessed at dose level 2. Eighteen and nine patients had the 6/6 and 6/7 genotypes, respectively. The maximum tolerated dose (MTD) was not observed up to dose level 4 in patients with the 6/6 genotype. In contrast, MTD was observed at dose level 2 (100 mg/m(2)) in patients with the 6/7 genotype. Patients with the 6/7 genotype had a significantly higher area under the plasma time-concentration curve (0-infinity) SN-38 (P = 0.022) and biliary index (P = 0.030) than those with 6/6. The recommended starting doses of biweekly irinotecan for phase II/III were 150 mg/m(2) for patients with the UGT1A1 6/6 genotype and 70 mg/m(2) for those with the 6/7 genotype, respectively. The gene polymorphism should be considered when determining the precise recommended doses to be administered in phase I studies.
[show abstract] [hide abstract]
ABSTRACT: To investigate into the diversity of UGT1A1 polymorphism across three different districts in Japan and highlight genetic differences among the population in Japan. We enrolled 50 healthy volunteers from each of the Yamaguchi (western part of Japan), Kochi (southern part of Japan) and Akita (northern part of Japan) prefectures. Blood samples (7 mL) were collected from each participant and stored in EDTA for subsequent genotyping by fragment size analysis, direct sequencing and TaqMan assay of UGT1A1*28, UGT1A7*3/UGT1A9*22 and UGT1A1*93/UGT1A1*6/UGT1A1*27/UGT1A1*60/UGT1A7 (-57), respectively. The only statistically significant differences in allele polymorphisms among the group examined were for UGT1A1*6. The Akita population showed more UGT1A1*6 heterozygosity (P = 0.0496). Our study revealed no regional diversity among UGT1A1, UGT1A7 or UGT1A9 polymorphisms in Japan.World journal of gastrointestinal oncology. 07/2012; 4(7):170-5.
Article: A genotype-directed phase I-IV dose-finding study of irinotecan in combination with fluorouracil/leucovorin as first-line treatment in advanced colorectal cancer.[show abstract] [hide abstract]
ABSTRACT: Infusional fluorouracil/leucovorin (FU/LV) plus irinotecan (FOLFIRI) is one of the standard first-line options for patients with metastatic colorectal cancer (mCRC). Irinotecan is converted into 7-ethyl-10-hydroxycamptothecin (SN-38) by a carboxylsterase and metabolised through uridine diphosphate glucuronosyl transferase (UGT1A1). The UGT1A1*28 allele has been associated with the risk of developing severe toxicities. The present trial was designed to define the maximum tolerated dose according to UGT1A1 genotype. This report focuses on the results of tolerance to different escalated doses of FOLFIRI first-line of chemotherapy. Patients undergoing first-line treatment for mCRC and eligible for treatment with FOLFIRI were classified according to UGT1A1 genotype. A total of 94 patients were eligible for dose escalation of irinotecan. The starting dose of biweekly irinotecan was 180 mg m(-2) for the *1/*1, 110 mg m(-2) for the *1/*28 and 90 mg m(-2) for the *28/*28 genotypes. The dose of irinotecan was escalated to 450 mg m(-2) in patients with the *1/*1 genotype, to 390 mg m(-2) in those with the *1/*28 genotype and to 150 mg m(-2) in those with the *28/*28 genotype. Neutropenia and diarrhoea were the most common grade 3 or 4 toxicities. Our results demonstrated that the recommended dose of 180 mg m(-2) for irinotecan in FOLFIRI is considerably lower than the dose that can be tolerated for patients with the UGT1A1 *1/*1 and *1/*28 genotypes. The maximum tolerable dose (MTD) in patients with a high-risk UGT1A1 *28/*28 genotype is 30% lower than the standard dose of 180 mg m(-2).British Journal of Cancer 06/2011; 105(1):53-7. · 5.04 Impact Factor
Article: Association between UGT1A1*28 Polymorphisms and Clinical Outcomes of Irinotecan-Based Chemotherapies in Colorectal Cancer: A Meta-Analysis in Caucasians.[show abstract] [hide abstract]
ABSTRACT: BACKGROUND: Whether UGT1A1*28 genotype is associated with clinical outcomes of irinotecan (IRI)-based chemotherapy in Colorectal cancer (CRC) is an important gap in existing knowledge to inform clinical utility. Published data on the association between UGT1A1*28 gene polymorphisms and clinical outcomes of IRI-based chemotherapy in CRC were inconsistent. METHODOLOGYPRINCIPAL FINDINGS: Literature retrieval, trials selection and assessment, data collection, and statistical analysis were performed according to the PRISMA guidelines. Primary outcomes included therapeutic response (TR), progression-free survival (PFS) and overall survival (OS). We calculated odds ratios (OR) and hazard ratios (HR) with 95% confidence intervals (CI). Twelve clinical trials were included. No statistical heterogeneity was detected in analyses of all studies and for each subgroup. Differences in TR, PFS and OS for any genotype comparison, UGT1A1*28/*28 versus (vs) UGT1A1*1/*1 (homozygous model), UGT1A1*1/*28 vs UGT1A1*1/*1 (heterozygous model), and UGT1A1*28/*28 vs all others (recessive model, only for TR) were not statistically significant. IRI dose also did not impact upon TR and PFS differences between UGT1A1 genotype groups. A statistically significant increase in the hazard of death was found in Low IRI subgroup of the homozygous model (HR = 1.48, 95% CI = 1.06-2.07; P = 0.02). The UGT1A1*28 allele was associated with a trend of increase in the hazard of death in two models (homozygous model: HR = 1.22, 95% CI = 0.99-1.51; heterozygous model: HR = 1.13, 95% CI = 0.96-1.32). These latter findings were driven primarily by one single large study (Shulman et al. 2011). CONCLUSIONSSIGNIFICANCE: UGT1A1*28 polymorphism cannot be considered as a reliable predictor of TR and PFS in CRC patients treated with IRI-based chemotherapy. The OS relationship with UGT1A1*28 in the patients with lower-dose IRI chemotherapy requires further validation.PLoS ONE 01/2013; 8(3):e58489. · 4.09 Impact Factor