[Show abstract][Hide abstract] ABSTRACT: This phase I/II study determined the recommended dose of FOLFIRI (irinotecan, infusional 5-fluorouracil and leucovorin) for Japanese patients with advanced colorectal cancer, and evaluated safety at the recommended dose in patients without the UDP-glucuronosyltransferase 1A1*28 allele which caused reduced enzyme expression.
The phase I part assessed the maximum tolerated dose of FOLFIRI to determine the recommended doses of irinotecan and infusional 5-fluorouracil. The doses were escalated from 150 to 180 mg/m(2) (irinotecan) and 2000 to 2400 mg/m(2) (5-fluorouracil). UDP-glucuronosyltransferase 1A1*6 and *28, and pharmacokinetics of irinotecan were observationally examined. In the phase II part, patients without the UDP-glucuronosyltransferase 1A1*28 allele received FOLFIRI at the recommended dose to evaluate safety.
Among 15 patients in the phase I part, dose-limiting toxicity (diarrhea) occurred in one patient who received 150 mg/m(2) irinotecan and 2400 mg/m(2) infusional 5-fluorouracil. The respective recommended doses were 180 and 2400 mg/m(2) for irinotecan and infusional 5-fluorouracil, without reaching the maximum tolerated dose. Twenty-five patients received FOLFIRI at the recommended doses. Grade 3 or 4 neutropenia occurred in 44%, and Grade 3 diarrhea in 4%.
This phase I/II study demonstrates that the recommended doses of irinotecan and infusional 5-fluorouracil in FOLFIRI for Japanese patients with advanced colorectal cancer who do not possess the UDP-glucuronosyltransferase 1A1*28 allele are 180 and 2400 mg/m(2), respectively. Toxicities occurring at the recommended doses are manageable in these patients.
Full-text · Article · Oct 2010 · Japanese Journal of Clinical Oncology
[Show abstract][Hide abstract] ABSTRACT: S-1 is an oral anticancer agent that combines tegafur, a prodrug of 5-fluorouracil (5-FU), and 5-chloro-2,4-dihydroxypyridine (CDHP), an inhibitor of dihydropyrimidine dehydrogenase. We examined the effects of aging on the pharmacokinetics of the components of S-1. The median area under the concentration-time curve (AUC) of active 5-FU did not significantly differ between 10 patients 75 years or older and 53 patients younger than 75 years (P = 0.598, Mann-Whitney U test). It is interesting to note that the median oral clearance of tegafur in patients 75 years or older was significantly lower than that in patients younger than 75 years (P = 0.011). Furthermore, the median AUC of CDHP was significantly higher in patients 75 years or older than in those younger than 75 years (P = 0.004). This effect was caused by reduced renal function in the elderly, because CDHP is excreted in the urine by glomerular filtration. The opposing effects of aging on the oral clearance of tegafur and the AUC of CDHP may offset each other, leading to unchanged systemic exposure of 5-FU.
No preview · Article · Jun 2009 · Drug metabolism and disposition: the biological fate of chemicals
[Show abstract][Hide abstract] ABSTRACT: To investigate the effects of genetic polymorphisms on morphine-induced adverse events in cancer patients.
We examined the relation of morphine-related adverse events to polymorphisms in UDP-glucuronosyltransferase (UGT) 2B7, ATP-binding cassette, sub-family B, number 1 (ABCB1), and μ-opioid receptor 1 genes in 32 Japanese cancer patients receiving oral controlled-release morphine sulfate tablets.
The T/T genotype at 1236 or TT/TT diplotype at 2677 and 3435 in ABCB1 was associated with significantly lower frequency of fatigue (grades 1-3) (P = 0.012 or 0.011, Fisher’s exact test). The UGT2B7*2 genotype was associated with the frequency of nausea (grades 1-3) (P = 0.023). The frequency of nausea was higher in patients without UGT2B7*2 allele than others. The diplotype at 2677 and 3435 in ABCB1 was associated with the frequency of vomiting (grades 1-3) (P = 0.011). No patient whose diplotype was consisted of no GC allele at 2677 and 3435 suffered from vomiting.
Our findings suggest that pharmacogenetics can be used to predict the risk of morphine-induced adverse events.
Full-text · Article · Jun 2009 · Cancer Chemotherapy and Pharmacology
[Show abstract][Hide abstract] ABSTRACT: S-1 is an oral anticancer agent that combines tegafur (FT) with 5-chloro-2,4-dihydroxypyridine (CDHP) and potassium oxonate. The recommended initial dose of S-1 is 120 mg/day for patients with a body surface area (BSA) of > or =1.5 m(2) in Japan.
We examined the effects of using this fixed dose on the pharmacokinetics of FT, CDHP, and active 5-fluorouracil (5-FU) on the basis of actual BSA. The pharmacokinetics was compared between patients with a BSA of 1.5-1.75 m(2) and those with a BSA of > or =1.75 m(2).
The median areas under the time-concentration curves (AUCs) of 5-FU and CDHP were significantly lower in patients with a BSA of > or =1.75 m(2) than in those with a BSA of 1.5-1.75 m(2) (P = 0.005 and 0.006, respectively; Mann-Whitney U-test). There was no difference between the groups in the median AUC of FT.
Systemic exposure to 5-FU is significantly lower in Japanese cancer patients with a large BSA of >1.75 m(2) who received the recommended fixed dose of S-1.
Full-text · Article · Apr 2009 · Annals of Oncology
[Show abstract][Hide abstract] ABSTRACT: ATP-binding cassette, sub-family C, number 2 (ABCC2) is involved in the biliary excretion of irinotecan and its metabolites, SN-38 and SN-38 glucuronide. Effects of the ABCC2 genotype on the pharmacokinetics (PK) of irinotecan and the metabolites were examined in Japanese patients with metastatic colorectal cancer receiving irinotecan plus infusional 5-fluorouracil/leucovorin (FOLFIRI). ABCC2 genotypes (-1549G>A, -1023G>A, -1019A>G, -24C>T, 1249G>A and 3972C>T) and haplotypes were analyzed for 67 patients with cancer. PK was also examined in a subset of 31 patients receiving FOLFIRI. Relationship between the ABCC2 genotypes or diplotypes and area under the time-concentration curve (AUC) of irinotecan and the metabolites normalized by irinotecan dose was analyzed. The lower AUC of irinotecan was seen in patients with A/A or G/A genotypes at 1249 of the ABCC2 gene than others (p=0.011, Mann-Whitney U teat). AUC of SN-38 in patients with A/A or G/A genotypes at -1023 was significantly lower than that in others (p=0.018). The haplotype I included -1023A (GAACGC) was the most frequent one with the allele frequency of 0.366. The AUC of SN-38 observed in patients with diplotypes harboring at least one haplotype I was lower than that observed in others (p=0.023). The haplotype IV consisted of 1249 (GGACAC) and was the fourth most frequent one with the allele frequency of 0.127. Patients with diplotypes carrying at least one haplotype IV showed lower AUC of irinotecan than others (p=0.011). Thus, ABCC2 genotype is one of the predictors of the variability of irinotecan PK in Japanese patients with metastatic colorectal cancer receiving FOLFIRI.
[Show abstract][Hide abstract] ABSTRACT: S-1 is an oral anticancer agent composed of tegafur (FT), 5-chloro-2,4-dihydroxypyridine (CDHP), and potassium oxonate. CDHP is added to prevent degradation of 5-fluorouracil (5-FU) by inhibiting dihydropyrimidine dehydrogenase. CYP2A6 is involved in the biotransformation of FT to 5-FU. Thus, we prospectively analyzed the effects of the CYP2A6 genotype, plasma level of CDHP, and patient characteristics on the pharmacokinetic (PK) variability of FT and 5-FU. Fifty-four Japanese patients with metastatic or recurrent cancers who received S-1 were enrolled. The CYP2A6 polymorphisms (*4A, *7, and *9) with deficient or reduced activity were analyzed. All subjects were classified into three groups according to their CYP2A6 genotype: wild type (*1/*1), one-variant allele (*1/any), or two-variant alleles (combination other than *1). The PK of FT, 5-FU, and CDHP were measured on day 1 of treatment. Multivariate regression analysis revealed that oral clearance of FT was associated with the CYP2A6 genotype (analysis of variance [ANOVA], P = 0.000838). The oral clearance of FT seen in patients with the two-variant alleles was significantly lower than those in wild type and the one-variant allele (95% confidence intervals 0.75-2.41 and 0.41-1.82, respectively; Tukey-Kramer test). The area under the time-concentration curve (AUC) of 5-FU was significantly correlated with the AUC of CDHP (ANOVA, P = 0.00126). The AUC of 5-FU and CDHP were inversely correlated with creatinine clearance (ANOVA, P = 0.0164 and P = 0.000762, respectively). Although the CYP2A6 variants are the cause of the PK variability of FT, the AUC of CDHP affected by renal function is the key determinant of the variability in the PK of 5-FU.
[Show abstract][Hide abstract] ABSTRACT: It has been reported that akathisia is a neurological side effect induced by antiemetic drugs and/or antipsychotics. Akathisia can occur in any area of the body, but respiratory akathisia is an unusual type of akathisia. Cases of respiratory akathisia in cancer patients taking antiemetic drugs have not previously been reported.
We report on a case of a cancer patient taking prochlorperazine as an antiemetic drug who experienced dyspnea accompanied by severe restlessness associated with respiration. By administration of biperiden, his restlessness in respiration and dyspnea promptly disappeared.
This finding led us to conclude that this cancer patient was experiencing respiratory akathisia.
Respiratory akathisia is uncommon. It is important for cancer patients that dyspnea induced by disease progression be ruled out as a cause of the respiratory restlessness. It is necessary to consider the possibility of akathisia in patients that complain of vague anxiety, chest discomfort, or dyspnea following antipsychotic medication.
Full-text · Article · Apr 2008 · Palliative and Supportive Care
[Show abstract][Hide abstract] ABSTRACT: Pharmacogenetic testing for UDP-glucuronosyltransferase (UGT) 1A1*28, a promoter variant of the UGT1A1 gene, is now carried out clinically to estimate the risk of irinotecan-associated toxicity. We studied the clinical significance of UGT1A1*6 and UGT1A1*27, two variants in exon 1 of the UGT1A1 gene that are found mainly in Asians. The study group comprised 46 Japanese patients who received various regimens of chemotherapy including irinotecan at doses from 50 to 180 mg/m(2). Pharmacogenetic relationships were explored between the UGT1A1 genotype and the ratio of the area under the plasma concentration-time curve (AUC) of the active metabolite of irinotecan (SN-38) to that of SN-38 glucuronide (SN-38G), used as a surrogate for UGT1A1 activity (AUC(SN-38)/AUC(SN-38G)). No patient was homozygous for UGT1A1*28, and none had UGT1A1*27. Two were heterozygous for UGT1A1*28. Two were homozygous and 15 heterozygous for UGT1A1*6, all of whom were wild type with respect to UGT1A1*28. Two patients were simultaneously heterozygous for UGT1A1*28 and UGT1A1*6, present on different chromosomes. The other 25 patients had none of the variants studied. The two patients simultaneously heterozygous for UGT1A1*28 and UGT1A1*6 and the two patients homozygous for UGT1A1*6 had significantly higher AUC(SN-38)/AUC(SN-38G) ratios than the others (P = 0.0039). Concurrence of UGT1A1*28 and UGT1A1*6, even when heterozygous, altered the disposition of irinotecan remarkably, potentially increasing susceptibility to toxicity. Patients homozygous for UGT1A1*6 should also be carefully monitored. UGT1A1 polymorphisms in the coding region of the UGT1A1 gene should be genotyped in addition to testing for UGT1A1*28 to more accurately predict irinotecan-related toxicity, at least in Asian patients.
[Show abstract][Hide abstract] ABSTRACT: We sequenced from 5'-franking region to intron 1 (to 337 bp downstream from exon 1) of the UDP-glucuronosyltransferase (UGT) 1A9 gene prepared from 55 Japanese cancer patients. Seven single nucleotide polymorphisms (SNPs) were found. Two of them were UGT1A9 -118(T)n (n=10) and UGT1A9*5, and four were reported SNPs in intron 1 of UGT1A9 gene (89540C>T, 89549G>A, 89616T>A and 89710A>C). A novel SNP (89587T>C) was found. The sequence is as follows: SNP, 050824FujitaK001; Gene Name, UGT1A9; Accession Number, AF297093; Length, 25 bases; 5'-CCTTCTTGAAGAT/CATGTATTTATAA-3'. Two patients were heterozygous for the mutant allele, resulting in the allele frequency of 1.82%.
Full-text · Article · Feb 2006 · Drug Metabolism and Pharmacokinetics
[Show abstract][Hide abstract] ABSTRACT: We sequenced exon 1 of the UDP-glucuronosyltransferase (UGT) 1A7 gene from 52 Japanese cancer patients. Four single nucleotide polymorphisms (SNPs) were found. Three of them caused UGT1A7*2 and UGT1A7*3. A novel SNP (98973G>C) causing amino acid substitution (Ser141Cys) was found. The sequence is as follows: SNP, 050824FujitaK002; Gene Name, UGT1A7; Accession Number, AF297093; Length, 25 bases; 5'-TAAAGGAGAGTTG/CTTTTGATGCAGT-3'. One out of 52 cancer patients was heterozygous for the variant allele, resulting in the allele frequency of 0.96%. The patient did not possess UGT1A7*2 or UGT1A7*3.
Full-text · Article · Feb 2006 · Drug Metabolism and Pharmacokinetics
[Show abstract][Hide abstract] ABSTRACT: Gefitinib (Iressa) is an anticancer drug that selectively inhibits tyrosine kinases of epidermal growth factor receptor. Gefitinib might affect CYP3A4-mediated metabolism, since the drug is a substrate of human CYP3A. In this study, we evaluated the effects of gefitinib on drug metabolism catalyzed by human CYP3A4. The effects of gefitinib on the CYP3A4-mediated formation of NPC (7-ethyl-10-(4-amino-1-piperidino)carbonyloxycamptothecin) and that of APC (7-ethyl-10-[4-N-(5-aminopentanoic acid)-1-piperidino]carbonyloxycamptothecin) from irinotecan were examined with the use of human liver and small intestinal microsomes. Gefitinib inhibited the formation of NPC in liver and small intestinal microsomes. The apparent intrinsic metabolic clearance (CL(int)) in the presence of 40 microM gefitinib was equivalent to about 26% of control in liver microsomes and 45% of control in small intestinal microsomes. Gefitinib stimulated the formation of APC by CYP3A4. CL(int) in the presence of 20 microM gefitinib with human liver microsomes was about 1.9 times higher than control. In human small intestinal microsomes, APC formation was enhanced by the addition of gefitinib at concentrations 20 microM or higher. CL(int) in the presence of 40 microM gefitinib was 2.8 times higher than control. Thus, we discovered that gefitinib inhibited the formation of NPC but stimulated the formation of APC from irinotecan.
Full-text · Article · Jan 2006 · Drug Metabolism and Disposition
[Show abstract][Hide abstract] ABSTRACT: Purpose: S-1, which is an oral anticancer agent comprised of tegafur (FT), 5-chloro-2,4-dihydroxipyridine (CDHP) and potassium oxonate, is one of the most widely prescribed agents in the treatment of gastric and colorectal cancer in Japan. CYP2A6 is involved in the bioactivation of FT to 5-FU. Dihydropyrimidine dehydrogenase which is responsible for the detoxification of 5-FU is inhibited by CDHP to increase plasma exposure of 5-FU. This study was designed to examine the contributions of CYP2A6 genotype, plasma CDHP levels, and patient's characteristics to the pharmacokinetics (PK) of FT and 5-FU. Methods: Forty Japanese patients with metastatic/recurrent cancers who received S-1 were enrolled. Polymorphisms in CYP2A6 (*4, *7 and *9) were analyzed. Genotypes were defined as wild type (*1/*1), one-variant alleles (*1/any) and two-variant alleles (combination other than *1). Plasma concentrations of FT, 5-FU, and CDHP were measured on treatment day 1. Multivariate regression analysis was used to identify possible associations of oral clearance (CL/F) of FT or the area under the time-concentration curve (AUC) for 5-FU with various factors, including CYP2A6 genotype, the AUC for CDHP, and patient's characteristics such as body surface area (BSA). Results: CL/F of FT was associated only with CYP2A6 genotype (analysis of variance [ANOVA], P=0.000891, R2=0.51). The CL/F of FT seen in patients with one- and two-variant alleles was significantly lower than that seen in wild type, respectively (Tukey-Kramer test). The AUC0-8 for 5-FU correlated with only the AUC0-inf for CDHP (ANOVA, P=0.00579, R2=0.44). The AUCs for 5-FU and CDHP correlated with creatinine clearance (ANOVA, P=0.0160, R2=0.14 and P=0.000560, R2=0.27, respectively). Conclusions: PK of FT is significantly affected by CYP2A6 genotype, whereas PK of 5-FU depends on CDHP exposure, indicating that the AUC for 5-FU depends largely on the activity of DPD, the rate-limiting drug-metabolizing enzyme involved in the detoxification of 5-FU. In addition, AUC for CDHP, which is correlated with creatinine clearance, is the critical factor to regulate AUC for 5-FU. Creatinine clearance should be considered to adjust the S-1 dose in the prescription of the drug.