Early dose reduction/delay and the efficacy of liposomal irinotecan with fluorouracil and leucovorin in metastatic pancreatic ductal adenocarcinoma (mPDAC): A post hoc analysis of NAPOLI-1.

BACKGROUND: Chemotherapy dose modification to manage adverse events is commonplace in clinical practice. This exploratory analysis evaluates the impact of liposomal irinotecan dose modification on overall survival (OS) and progression-free survival (PFS) in the NAPOLI-1 clinical trial (NCT01494506). METHODS: Analysis includes only patients enrolled under protocol version 2 who received at least the first 2 scheduled doses of study drug. Within the liposomal irinotecan +5 fluorouracil/leucovorin (5 FU/LV) arm, patients were grouped according to whether or not they had a dose modification within the first 6 weeks. Dose reduction was defined as any decrease from initial dose; dose delay was any dosing delay >3 days from target date. OS and PFS (Kaplan-Meier estimates) were compared within the liposomal irinotecan+5-FU/LV arm and between treatment arms. Unstratified hazard ratios (HRs) were calculated using Cox regression analysis. RESULTS: Of the 93 patients from the liposomal irinotecan+5 FU/LV arm included in the analysis, 53 experienced a dose modification (both delay and reduction, n = 30; delay only, n = 19; reduction only, n = 4). No apparent difference in median OS or PFS was observed between patients who did versus patients who did not have a dose modification (OS: 8.4 vs 6.7 months; HR, 0.89; PFS: 4.2 vs 3.1 months; HR, 0.74). CONCLUSION: An early dose reduction or delay of liposomal irinotecan+5-FU/LV in the first 6 weeks does not significantly impact OS or PFS compared to patients without dose modifications. This finding suggests that tolerability-guided dose modification of liposomal irinotecan does not adversely affect efficacy outcomes.

Phase I study of imalumab (BAX69), a fully human recombinant antioxidized macrophage migration inhibitory factor antibody in advanced solid tumours.

AIM: Preclinical evidence suggests that oxidized macrophage migration inhibitory factor (oxMIF) may be involved in carcinogenesis. This phase 1 study (NCT01765790) assessed the safety, tolerability, pharmacokinetics and antitumour activity of imalumab, an oxMIF inhibitor, in patients with advanced cancer using '3 + 3' dose escalation. METHODS: In Schedule 1, patients with solid tumours received doses from 1 to 50 mg/kg IV every 2 weeks. In Schedule 2, patients with metastatic colorectal adenocarcinoma, non-small-cell lung, or ovarian cancer received weekly doses of 10 or 25 mg/kg IV (1 cycle = 28 days). Treatment continued until disease progression, unacceptable toxicity, dose-limiting toxicity, or withdrawal of consent. RESULTS: Fifty of 68 enrolled patients received imalumab. The most common treatment-related adverse events (TRAEs) included fatigue (10%) and vomiting (6%); four grade 3 serious TRAEs (two patients) occurred. The dose-limiting toxicity was allergic alveolitis (one patient, 50 mg/kg every 2 weeks). The maximum tolerated and biologically active doses were 37.5 mg/kg every 2 weeks and 10 mg/kg weekly, respectively. Of 39 assessed patients, 13 had stable disease (≥4 months in 8 patients). CONCLUSIONS: Imalumab had a maximum tolerated dose of 37.5 mg/kg every 2 weeks in patients with advanced solid tumours, with a biologically active dose of 10 mg/kg weekly. Further investigation will help define the role of oxMIF as a cancer treatment target.

Quality-adjusted survival with combination nal-IRI+5-FU/LV vs 5-FU/LV alone in metastatic pancreatic cancer patients previously treated with gemcitabine-based therapy: a Q-TWiST analysis.

BACKGROUND: In the NAPOLI-1 Phase 3 trial, nal-IRI+5-fluorouracil and leucovorin (5-FU/LV) significantly improved median overall survival (6.1 vs 4.2 months, P=0.012) and progression-free survival (3.1 vs 1.5 months, P=0.0001) vs 5-FU/LV alone in metastatic pancreatic adenocarcinoma patients previously treated with gemcitabine-based therapy. This analysis evaluated between treatment differences in quality-adjusted time without symptoms of disease progression or toxicity (Q-TWiST). METHODS: Overall survival was partitioned into time with grade ⩾3 toxicity (TOX), disease progression (REL), and time without disease progression symptoms or grade ⩾3 toxicity (TWiST). Mean Q-TWiST was calculated by weighting time spent by a utility of 1.0 for TWiST and 0.5 for TOX and REL. In threshold analyses, utility for TOX and REL were varied from 0.0 to 1.0. RESULTS: Patients in nal-IRI+5-FU/LV (n=117) vs 5-FU/LV (n=119) had significantly more mean time in TWiST (3.4 vs 2.4 months) and TOX (1.0 vs 0.3 months) but similar REL (2.5 vs 2.7 months). In the base case, nal-IRI+5-FU/LV patients had 1.3 months (95% CI, 0.4-2.1; 5.1 vs 3.9) greater Q-TWiST (threshold analyses range: 0.9-1.6 months). CONCLUSIONS: Within NAPOLI-1, nal-IRI+5-FU/LV resulted in statistically significant and clinically meaningful gains in quality-adjusted survival vs 5-FU/LV alone.

The role of cancer nurses in cancer-related pain management in Europe.

Cancer pain is a common symptom in patients with cancer and can largely affect their quality of life. Pain management is important to minimize the impact of pain on daily activities. Cancer nurses are significantly involved in all steps of pain management and contribute to the success of therapy through their knowledge and expertise. While they generally play an important role in the screening, assessment, diagnosis, treatment and follow-up of patients and their (pain) symptoms, this varies from country to country in Europe. An important aspect is their role in educating patients and their families about what pain is, what impact it can have, how it can be treated pharmacologically or non-pharmacologically and what effects or problems can occur during treatment. While there is a great discrepancy between education and training opportunities for cancer nurses in different European countries, there is a continued need for education and training in pain management. Cancer is increasingly becoming a chronic disease, and the management of pain in cancer survivors will be crucial to maintain an adequate quality of life. With this, the crucial role of cancer nurses is becoming even more important.

Effects of mannose-binding lectin polymorphisms on irinotecan-induced febrile neutropenia.

OBJECTIVE: Mannose-binding lectin (MBL) is important in the innate immune response. MBL2 gene polymorphisms affect MBL expression, and genotypes yielding low MBL levels have been associated with an elevated risk for infections in hematological cancer patients undergoing chemotherapy. However, these reported associations are inconsistent, and data on patients with solid tumors are lacking. Here, we investigated the effects of MBL2 genotypes on irinotecan-induced febrile neutropenia in patients with solid tumors. PATIENTS AND METHODS: Irinotecan-treated patients were genotyped for the MBL2 gene. Two promoter (-550 H/L and -221 X/Y) and three exon polymorphisms (52 A/D, 54 A/B, and 57 A/C) were determined, together with known risk factors for irinotecan-induced toxicity. Neutropenia and febrile neutropenia were recorded during the first course. RESULTS: Of the 133 patients, 28% experienced severe neutropenia and 10% experienced febrile neutropenia. No associations were found between exon polymorphisms and febrile neutropenia. However, patients with the H/H promoter genotype, associated with high MBL levels, experienced significantly more febrile neutropenia than patients with the H/L and L/L genotypes (20% versus 13% versus 5%). Moreover, patients with the HYA haplotype encountered significantly more febrile neutropenia than patients without this high MBL-producing haplotype (16% versus 4%). In the subgroup with wild-type exon polymorphisms (A/A), patients with the high MBL promoter phenotype had the highest incidence of febrile neutropenia, regardless of known risk factors. CONCLUSION: Patients with high MBL2 promoter genotypes and haplotypes seem more at risk for developing febrile neutropenia. If confirmed, these preliminary findings may contribute to more individualized approaches of irinotecan treatment.

Liposomal irinotecan and 5-fluorouracil/leucovorin in older patients with metastatic pancreatic cancer - A subgroup analysis of the pivotal NAPOLI-1 trial.

OBJECTIVES: Pancreatic cancer is a highly lethal disease predominantly affecting older patients. Characterization of outcomes in these patients may help optimise treatment decisions. The global, phase 3 NAPOLI-1 trial (NCT01494506) demonstrated an overall survival (OS) benefit with liposomal irinotecan and 5-flurouracil/leucovorin (nal-IRI + 5-FU/LV) versus 5-FU/LV. This subgroup analysis explored impact of age on outcomes in NAPOLI-1 patients, and nal-IRI + 5-FU/LV efficacy and safety in older patients. MATERIALS AND METHODS: This exploratory, post-hoc analysis of the NAPOLI-1 trial included patients aged ≥eighteen years (no upper limit) with metastatic pancreatic adenocarcinoma that had progressed on gemcitabine-based therapy. Patients were stratified by age (cut-offs at 65, 70, and 75 years); OS and progression-free survival (PFS) were estimated by Kaplan-Meier analysis. RESULTS: Of 417 randomized patients, 192 (46%), 110 (26%) and 43 (10%) were aged ≥65, ≥70 and ≥ 75 years, respectively. Mortality risk and risk of disease progression were similar in older and younger patients independent of treatment (HRs for median [m]OS/mPFS comparisons were 0.88/0.95 [<65 versus ≥65 years], 0.89/0.88 [<70 versus ≥70 years] and 1.04/0.98 [<75 versus ≥75 years]; P > .25). Reduced mortality/morbidity risk with nal-IRI + 5-FU/LV in older subgroups was in line with the wider population. No additional toxicities with nal-IRI + 5-FU/LV were observed in older patients: 86% of patients ≥75 years versus 69% <75 years required a dose delay or reduction due to toxicities (43% versus 32% dose reductions). DISCUSSION: Results suggest that older patients with metastatic pancreatic adenocarcinoma that progressed on prior gemcitabine-based treatment can benefit from second-line therapy, supporting nal-IRI + 5-FU/LV treatment in older patients.

NAPOLI-1 phase 3 study of liposomal irinotecan in metastatic pancreatic cancer: Final overall survival analysis and characteristics of long-term survivors.

BACKGROUND: Liposomal irinotecan (nal-IRI) plus 5-fluorouracil and leucovorin (5-FU/LV) is approved for patients with metastatic pancreatic ductal adenocarcinoma (mPDAC) previously treated with gemcitabine-based therapy. This approval was based on significantly improved median overall survival compared with 5-FU/LV alone (6.1 vs 4.2 months; hazard ratio [HR], 0.67) in the global phase 3 NAPOLI-1 trial. Here, we report the final survival analysis and baseline characteristics associated with long-term survivors (survival of ≥1 year) in the NAPOLI-1 trial. PATIENTS AND METHODS: Patients with mPDAC were randomised to receive nal-IRI + 5-FU/LV (n = 117), nal-IRI (n = 151), or 5-FU/LV (n = 149) for the first 4 weeks of 6-week cycles. Baseline characteristics and efficacy in the overall population were compared with those in patients who survived ≥1 year. Through 16th November 2015, 382 overall survival events had occurred. RESULTS: The overall survival advantage for nal-IRI+5-FU/LV vs 5-FU/LV was maintained from the original nanoliposomal irinotecan with fluorouracil and folinic acid in metastatic pancreatic cancer after previous gemcitabine-based therapy (NAPOLI-1) analysis (6.2 vs 4.2 months, respectively; HR, 0.75; 95% confidence interval: 0.57-0.99). Median progression-free survival, objective response rate and disease control rate also favoured nal-IRI+5-FU/LV therapy. Estimated one-year overall survival rates were 26% with nal-IRI+5-FU/LV and 16% with 5-FU/LV. Baseline characteristics associated with long-term survival in the nal-IRI+5-FU/LV arm were Karnofsky performance status ≥90, age ≤65 years, lower CA19-9 levels, neutrophil-to-lymphocyte ratio ≤5 and no liver metastases. No new safety concerns were detected. CONCLUSIONS: The survival benefits of nal-IRI+5-FU/LV versus 5-FU/LV were maintained over an extended follow-up, and prognostic markers of survival ≥1 year were identified. CLINICAL TRIAL REGISTRATION NUMBER: NCT01494506.

Quality of life in metastatic pancreatic cancer patients receiving liposomal irinotecan plus 5-fluorouracil and leucovorin.

BACKGROUND: The NAPOLI-1 study (NCT01494506) reported that liposomal irinotecan plus 5-fluorouracil and leucovorin (nal-IRI+5-FU/LV) improved overall survival vs 5-FU/LV with manageable toxicity in patients with metastatic pancreatic adenocarcinoma previously treated with gemcitabine-based therapy. Yet, clinicians need treatment strategies that also maintain the patient's health-related quality of life (HRQOL). Here, we report the HRQOL data. METHODS: Patients completed the European Organisation for Research and Treatment of Cancer QOL core questionnaire C30 (EORTC QLQ-C30) at baseline, every 6 weeks, and at 30 days after discontinuation of study treatment. Patient-reported outcomes (PROs) were scored according to EORTC guidelines. nal-IRI+5-FU/LV HRQOL was compared with 5-FU/LV. The PRO population comprised intent-to-treat patients who completed baseline and at least one subsequent assessment on the EORTC QLQ-C30. Data were also analysed for missingness. RESULTS: Of 236 patients in the intent-to-treat population, 128 (54.2%) comprised the PRO population (71 in the nal-IRI+5-FU/LV arm; 57 the in 5-FU/LV arm). Of the remaining 108 patients (45.8%) not included in the PRO population, most progressed rapidly, making participation difficult. Median change from baseline was ≤10 points at weeks 6 and 12 in global health status or functional and symptom scale scores, except for fatigue, which deteriorated by 11.1 points with nal-IRI+5-FU/LV but did not change vs 5-FU/LV. The proportion of patients whose HRQOL improved or deteriorated was not significantly different between the arms. CONCLUSION: In the NAPOLI-1 study, HRQOL was maintained with nal-IRI+5-FU/LV in patients with metastatic pancreatic adenocarcinoma previously treated with a gemcitabine-based regimen, while survival was significantly extended.

Lifestyle habits as a contributor to anti-cancer treatment failure.

Lifestyle may have serious consequences for cancer treatment outcome, which is a fact that both physicians and patients are often not explicitly aware of, thereby unwillingly exposing the patient to possible danger. In certain cases, patient behaviour can lead to potentially life-threatening adverse events, whilst in other cases the clinical benefit of anti-cancer therapy can be diminished. In this review, we focus on the role of certain habits (like cigarette smoking, alcohol use and the use of complementary and alternative medicine) and discuss the effects they may have on anti-cancer medication. Also patient compliance to prescribed anti-cancer drugs is a factor frequently overlooked if treatment does not follow the expectations, which gains importance with the increasingly frequent prescription of oral anti-cancer agents.

Survival with nal-IRI (liposomal irinotecan) plus 5-fluorouracil and leucovorin versus 5-fluorouracil and leucovorin in per-protocol and non-per-protocol populations of NAPOLI-1: Expanded analysis of a global phase 3 trial.

BACKGROUND: In the phase 3 randomised NAPOLI-1 clinical study, a 45% increase in median overall survival (OS) was shown with liposomal irinotecan, 5-fluorouracil and leucovorin (nal-IRI+5-FU/LV) versus 5-FU/LV in patients with metastatic pancreatic cancer progressing after gemcitabine-based therapy. Here, we report data from a pre-specified, expanded analysis of outcomes in the per-protocol (PP) population. MATERIALS AND METHODS: The PP population comprised patients receiving ≥80% of planned treatment during the first 6 weeks, with no major protocol violations. A post-hoc analysis of the non-PP population was also performed. RESULTS: For PP patients, median OS was 8.9 (95% confidence interval: 6.4-10.5) months with nal-IRI+5-FU/LV (n = 66) vs 5.1 (4.0-7.2) months with 5-FU/LV (n = 71; unstratified hazard ratio [HR] 0.57, p = 0.011). For non-PP patients, it was 4.4 (3.3-5.3) months with nal-IRI+5-FU/LV (n = 51) vs 2.8 (1.7-3.2) months with 5-FU/LV (n = 48; unstratified HR 0.64, p = 0.0648). CONCLUSION: A statistically significant survival advantage was observed with nal-IRI+5-FU/LV vs 5-FU/LV in the PP patient population.

Medicinal cannabis in oncology.

In The Netherlands, since September 2003, a legal medicinal cannabis product, constituting the whole range of cannabinoids, is available for clinical research, drug development strategies, and on prescription for patients. To date, this policy, initiated by the Dutch Government, has not yet led to the desired outcome; the amount of initiated clinical research is less than expected and only a minority of patients resorts to the legal product. This review aims to discuss the background for the introduction of legal medicinal cannabis in The Netherlands, the past years of Dutch clinical experience in oncology practice, possible reasons underlying the current outcome, and future perspectives.

Association of enzyme and transporter genotypes with the pharmacokinetics of imatinib.

OBJECTIVE: Our objective was to explore the relationships between imatinib pharmacokinetics and 9 allelic variants in 7 genes coding for adenosine triphosphate-binding cassette transporters (ABCB1 and ABCG2) and enzymes (cytochrome P450 [CYP] 2C9, CYP2C19, CYP2D6, CYP3A4, and CYP3A5) of putative relevance for imatinib. METHODS: Imatinib transport in vitro was studied by use of human embryonic kidney 293 cells transfected with wild-type ABCG2 and an ABCG2 Q141K clone. Steady-state pharmacokinetics of imatinib was obtained in 82 patients with gastrointestinal stromal tumors treated with oral imatinib at doses ranging from 100 to 1000 mg/d. Genotyping was carried out via direct sequencing or restriction fragment length polymorphism-based techniques. RESULTS: Human embryonic kidney 293 cells transfected with ABCG2 Q141K exhibited greater drug accumulation in vitro in comparison with cells expressing wild-type ABCG2 (P = .028). However, pharmacokinetic parameters of imatinib in vivo were not statistically significantly different in 16 patients who were heterozygous for ABCG2 421C>A compared with 66 patients carrying the wild-type sequence (P = .479). The apparent oral clearance of imatinib was potentially reduced in individuals with at least 1 CYP2D6*4 allele (median, 7.78 versus 10.6 L/h; P = .0695). Pharmacokinetic parameters were not related to any of the other multiple-variant genotypes (P >or= .230), possibly because of the low allele frequencies. CONCLUSIONS: This study indicates that common genetic variants in the evaluated genes have only a limited impact on the pharmacokinetics of imatinib. Further investigation is required to quantitatively assess the clinical significance of homozygous variant ABCG2 and CYP2D6 genotypes in patients treated with imatinib.

Hepatic transport, metabolism and biliary excretion of irinotecan in a cancer patient with an external bile drain.

BACKGROUND: Irinotecan is metabolized by various enzymes, including carboxylesterases, cytochrome P450 3A isozymes (CYP3A) and uridine-diphosphate glucuronosyltransferase 1A isoforms (UGT1A). Here we report on the disposition of irinotecan and its metabolites in plasma, urine, bile and feces of a single cancer patient with an external bile drain. METHODOLOGY: Irinotecan (450 mg) was administered during a 90-minutes continuous infusion to a cancer patient with an external bile drain. Blood samples were collected up to 55 hours after infusion, while bile, feces and urine were collected during six consecutive days after administration. Samples were analyzed using high-performance liquid chromatography (HPLC)-assays with fluorescence detection. RESULTS: Plasma pharmacokinetics were characterized by a relatively slow clearance of irinotecan and a relatively high exposure to 7-ethyl-10-[4-N-(5-aminopentanoic acid)-1-piperidino] carbonyloxycamptothecin (APC). Exposures to the other metabolites was within the normal range. Overall, 83.4% of the administered dose was recovered in the excreta, with the majority excreted during the first 24 hours. CONCLUSIONS: Enterohepatic recirculation is of minor importance for the plasma disposition of irinotecan and its metabolites. The high percentage of the dose recovered in urine, the relatively slow clearance of irinotecan and the preferential urinary over biliary excretion of APC in this particular patient are likely related to reduced functioning of ABC-transporters. Circumstantial evidence was found that APC is subject to further intestinal biotransformation indicating a role in the etiology of irinotecan-induced diarrhea. Since intra-luminal exposure to SN-38 in patients with an external bile drain is limited, neutropenia will be the dose-limiting toxicity. Based on presented data, although collected from only one patient, irinotecan therapy in patients with an external bile drain is feasible. No a priori dose adjustments are recommended, although in the absence of severe side-effects in previous courses, a higher dose may be considered.

Role of pharmacogenetics in irinotecan therapy.

In the treatment of advanced colorectal cancer, irinotecan has become one of the most important drugs, despite its sometimes unpredictable adverse effects. To understand why some patients experience severe adverse effects (diarrhea and neutropenia), while others do not, the metabolic pathways of this drug have to be unraveled in detail. Individual variation in expression of several phase I and phase II metabolizing enzymes and ABC-transporters involved in irinotecan metabolism and excretion, at least partly explains the observed pharmacokinetic interpatient variability. Although the difference in expression-level of these proteins to a certain amount is explained by physiologic and environmental factors, the presence of specific genetic determinants also does influence their expression and function. In this review, the role of genetic polymorphisms in the main enzyme-systems (carboxylesterase, cytochrome P450 3A, and uridine diphosphate-glucuronosyltransferase) and ABC-transporters (ABCB1, ABCC2, and ABCG2) involved in irinotecan metabolism, are discussed. Since at this moment the field of pharmacogenetics and pharmacogenomics is rapidly expanding and simultaneously more rapid and cost-effective screening methods are emerging, a wealth of future data is expected to enrich our knowledge of the genetic basis of irinotecan metabolism. Eventually, this may help to truly individualize the dosing of this (and other) anti-cancer agent(s), using a personal genetic profile of the most relevant enzymes for every patient.

Phase I pharmacokinetic, food effect, and pharmacogenetic study of oral irinotecan given as semisolid matrix capsules in patients with solid tumors.

PURPOSE: To characterize the maximum-tolerated dose, recommended dose, dose-limiting toxicities (DLT), pharmacokinetic profile, and food effect of orally administered irinotecan formulated as new semisolid matrix capsules. EXPERIMENTAL DESIGN: Irinotecan was given orally in fasted patients once daily for 5 consecutive days and repeated every 3 weeks. Patients were randomly assigned to take the drug along with a high-fat, high-calorie breakfast for the administration at day 1 of the first or second cycle. Dosages tested were 70 and 80 mg/m(2)/day. RESULTS: Twenty-five patients received 101 cycles of therapy (median two cycles, range 1-15). During the first cycle, grade 3 delayed diarrhea and grade 3 fever were the DLTs at the dosage of 80 mg/m(2)/day in three out of five patients. Hematologic and nonhematologic toxicities were mild to moderate. Exposure to the active metabolite SN-38 was relatively high compared with i.v. infusion, but no relevant accumulation was observed. Food had no significant effect on irinotecan pharmacokinetics. One confirmed partial remission and 10 disease stabilizations were observed in previously treated patients. No association was found between the UGT1A1*28 genotype and the risk of severe irinotecan-induced toxicity. CONCLUSIONS: For oral irinotecan, a dose of 70 mg/m(2)/day for 5 consecutive days every 3 weeks is recommended for further studies. Delayed diarrhea was the main DLT, similar to that observed with intravenously administered irinotecan. This study confirms that oral administration of irinotecan is feasible and may have favorable pharmacokinetic characteristics.

Post-gemcitabine therapy for patients with advanced pancreatic cancer - A comparative review of randomized trials evaluating oxaliplatin- and/or irinotecan-containing regimens.

A systematic review and critical evaluation of randomized trial evidence for oxaliplatin- or irinotecan-containing regimens in patients with advanced pancreatic cancer previously treated with gemcitabine has not yet been published. We conducted a comparative systematic review of randomized trials evaluating oxaliplatin- or irinotecan-based therapies in patients with advanced pancreatic cancer previously treated with gemcitabine to assess trial similarity and the feasibility of performing an indirect treatment comparison (ITC). Studies were identified through PubMed and key oncology conference abstracts. The following trials met our criteria: NAPOLI-1 (nanoliposomal irinotecan [nal-IRI] or nal-IRI+5-fluorouracil [5-FU]/leucovorin [LV] vs 5-FU/LV), CONKO-003 (oxaliplatin+5-FU/LV [OFF] vs 5-FU/LV), PANCREOX (oxaliplatin+5-FU/LV [mFOLFOX6] vs 5-FU/LV), and Yoo et al. (2009) (irinotecan+5-FU/LV [mFOLFIRI3] vs mFOLFOX). Fundamental differences were identified in study design (i.e., number of study sites, number of countries), patient (i.e., locally advanced vs metastatic disease, stratification variables, prior and subsequent treatments) and treatment (i.e., regimens, dose intensity) characteristics, and primary and secondary outcomes (i.e., primary vs secondary outcomes, overall survival [OS], progression-free survival [PFS]) among the 4 included trials. Our comparative review demonstrated significant dissimilarity across trials, which precluded conducting an ITC. In the absence of head-to-head nal-IRI- and/or oxaliplatin-based therapy trials, clinicians are advised to interpret these studies separately within the context of their individual patient population.

Flat-fixed dosing of irinotecan: influence on pharmacokinetic and pharmacodynamic variability.

PURPOSE: In a previous analysis, it was shown that body-surface area (BSA) is not a predictor of irinotecan pharmacokinetic parameters. Here, we prospectively evaluated the effects of administering a flat-fixed irinotecan dose to cancer patients, regardless of BSA. EXPERIMENTAL DESIGN: Twenty-six cancer patients (12 females) received a fixed irinotecan dose of 600 mg, given as a 90-min i.v. infusion. Plasma concentrations of irinotecan and its metabolites SN-38 (7-ethyl-10-hydroxycamptothecin) and SN-38G (SN-38 glucuronide) were measured during the first cycle and analyzed using nonlinear mixed-effect modeling. Data were compared with those obtained in 47 cancer patients (19 females) who received irinotecan at a BSA-normalized dose of 350 mg/m(2). RESULTS: The interindividual variability in irinotecan clearance (25.9% versus 25.1%; P = 0.93), in relative extent of conversion to SN-38 (47.8% versus 42.7%; P = 0.24), and in relative extent of SN-38 glucuronidation (71.2% versus 72.4%; P = 0.95) were not significantly different between the two dose groups. Variance differences in irinotecan-mediated hematological side effects were also similar between the 600 mg and 350 mg/m(2) groups (P > 0.14). CONCLUSIONS: These findings suggest that flat-fixed dosing of irinotecan does not result in increased pharmacokinetic/pharmacodynamic variability and could be safely used to supplant current dosing strategies based on BSA.

ABCG2 pharmacogenetics: ethnic differences in allele frequency and assessment of influence on irinotecan disposition.

PURPOSE: The ATP-binding cassette transporter ABCG2 (breast cancer resistance protein) is an efflux protein that plays a role in host detoxification of various xenobiotic substrates, including the irinotecan metabolite 7- ethyl-10-hydroxycamptothecin (SN-38). The ABCG2 421C>A polymorphism has been associated with reduced protein expression and altered function in vitro. The aim of this study was to evaluate the ethnic distribution and potential functional consequence of the ABCG2 421C>A genotype in cancer patients treated with irinotecan. EXPERIMENTAL DESIGN: ABCG2 genotyping was performed using Pyrosequencing on DNA from 88 American Caucasians, 94 African Americans, 938 Africans, and 95 Han Chinese, as well as in 84 European Caucasian patients treated with irinotecan undergoing additional blood sampling for pharmacokinetic studies. RESULTS: Significant differences in allele frequencies were observed between the given world populations (P < 0.001), the variant allele being most common in the Han Chinese population with a frequency as high as 34%. The mean area under the curve of irinotecan and SN-38 were 19,851 and 639 ng x hour/mL, respectively. The frequency of the variant allele (10.7%) was in line with results in American Caucasians. No significant changes in irinotecan pharmacokinetics were observed in relation to the ABCG2 421C>A genotype, although one of two homozygous variant allele carriers showed extensive accumulation of SN-38 and SN-38 glucuronide. CONCLUSIONS: The ABCG2 421C>A polymorphism appears to play a limited role in the disposition of irinotecan in European Caucasians. It is likely that the contribution of this genetic variant is obscured by a functional role of other polymorphic proteins.

Role of imatinib mesylate (Gleevec/Glivec) in gastrointestinal stromal tumors.

Gastrointestinal stromal tumors are soft tissue sarcomas of the gastrointestinal tract that originate from mesenchymal cells. Advances in the systemic therapy of gastrointestinal stromal tumors are highlighted by the rapid development and approval of the molecularly targeted therapy imatinib mesylate (Gleevec/Glivec). Mutations of the KIT gene are known to be present in most gastrointestinal stromal tumors and result in gain of function, with permanent activation of the expressed KIT receptor in the absence of binding of the stem cell factor ligand. Imatinib is the first rationally designed selective inhibitor of specific protein tyrosine kinases, including KIT. Inhibiting the downstream signaling of KIT switches the cell balance into apoptosis. Although complete responses have seldom been seen up until now, imatinib has proven to be extremely effective in the treatment of patients with unresectable and/or metastatic gastrointestinal stromal tumors.

Determination of irinotecan (CPT-11) and SN-38 in human whole blood and red blood cells by liquid chromatography with fluorescence detection.

An analytical method was developed for the anticancer agent irinotecan (CPT-11) and its main metabolite SN-38 in human whole blood and in red blood cells (RBCs). Sample pretreatment involved deproteinization of whole blood or plasma-diluted RBCs isolated by MESED instruments, with a mixture of aqueous perchloric acid and methanol (1:1, v/v). Separation was carried out using isocratic elution on a Hypersil ODS stationary phase, with detection at excitation and emission wavelengths of 355 and 515 nm, respectively. The lower limit of quantitation (LLQ) in blood was established at 5.00 ng/ml for both compounds, with values for within-run precision (WRP) and between-run precision (BRP) of less than 10%. The method is currently being applied to investigate the blood distribution of CPT-11 and SN-38 in cancer patients.