Clinical validation of a prognostic tool in a population of outpatients treated for incurable cancer undergoing anticancer therapy: PRONOPALL study.

BACKGROUND: In 2008, a study of the characteristics of hospitalised patients led to the development of a prognostic tool that distinguished three populations with significantly different 2-month survival rates. The goal of our study aimed at validating prospectively this prognostic tool in outpatients treated for cancer in terminal stage, based on four factors: performance status (ECOG) (PS), number of metastatic sites, serum albumin and lactate dehydrogenase. PATIENTS AND METHODS: PRONOPALL is a multicentre study of current care. About 302 adult patients who met one or more of the following criteria: life expectancy under 6 months, performance status ≥ 2 and disease progression during the previous chemotherapy regimen were included across 16 institutions between October 2009 and October 2010. Afterwards, in order to validate the prognostic tool, the score was ciphered and correlated to patient survival. RESULTS: Totally 262 patients (87%) were evaluable (27 patients excluded and 13 unknown score). Median age was 66 years [37-88], and women accounted for 59%. ECOG PS 0-1 (46%), PS 2 (37%) and PS 3-4 (17%). The primary tumours were: breast (29%), colorectal (28%), lung (13%), pancreas (12%), ovary (11%) and other (8%). About 32% of patients presented one metastatic site, 35% had two and 31% had more than two. The median lactate dehydrogenase level was 398 IU/l [118-4314]; median serum albumin was 35 g/l [13-54]. According to the PRONOPALL prognostic tool, the 2-month survival rate was 92% and the median survival rate was 301 days [209-348] for the 130 patients in population C, 66% and 79 days [71-114] for the 111 patients in population B, and 24% and 35 days for [14-56] the 21 patients in population A. These three populations survival were statistically different (P <0.0001). CONCLUSION: PRONOPALL study confirms the three prognostic profiles defined by the combination of four factors. This PRONOPALL score is a useful decision-making tool in daily practice.

Evaluation in usual practice of the bevacizumab-FOLFIRI combination for the first-line treatment of patients with unresectable metastatic colorectal cancer treated in 2006: focus on resected patients and oncogeriatrics: AVASTIN OUEST cohort of the Observatory of Cancer of the Brittany and Pays de la Loire Areas (Observatoire dédié au Cancer Bretagne / Pays de la Loire).

BACKGROUND: In 2006, bevacizumab, a targeted therapy agent was combined with FOLFIRI for the firstline treatment of patients with unresectable metastatic colorectal cancer. METHODS/RESULTS: A study on a homogenous series of 111 patients from the Brittany and Pays de la Loire areas who received bevacizumab-FOLFIRI as first-line treatment in 2006 showed the following results: 51 responses, 29 stabilisations, 21 progressions and 10 cases of toxicity prior to assessment. Median overall survival (OS) was 25.1 months and median progression-free survival was 10.2 months. Surgery secondary to treatment tripled median OS which reached 59.2 months in resected patients versus 18.8 months in unresected patients. Comparison of patients aged more or less than 70 years showed no differences in terms of benefits or risks. CONCLUSION: Bevacizumab-FOLFIRI could be administered as part of a routine care protocol to elderly patients previously evaluated by a geriatric assessment and validated by a multidisciplinary staff.

En 2006, bevacizumab-FOLFIRI représente la thérapie ciblée administrable dès la première ligne chez les patients porteurs d'un cancer colorectal métastatique non opérable. Une série homogène de 111 patients colligés en région Bretagne et Pays de la Loire ayant reçu du bevacizumab- FOLFIRI en première ligne en 2006 révèle les résultats suivants: 51 réponses, 29 stabilités, 21 progressions et 10 toxicités avant évaluation. La médiane de survie globale (OS) est de 25,1 mois et la médiane de survie sans progression (PFS) de 10,2 mois. Dans le cas d'une chirurgie secondaire, l'OS médian triple de 18,8 mois chez les patients non réséqués versus 59,2 mois ceux réséqués. En comparant les sujets âgés de plus et de moins de 70 ans, aucune différence n'a été mise en évidence en termes de bénéfice ou de risque. Bevacizumab-FOLFIRI pourrait être administré en pratique courante chez les personnes âgées sous couvert d'une évaluation gériatrique et d'une approche multidisciplinaire.

[Dihydropyrimidine dehydrogenase deficiency and toxicity to fluoropyrimidine]. / Déficits en dihydropyrimidine déshydrogénase et toxicité aux fluoropyrimidines.

Dihydropyrimidine dehydrogenase (DPD) is a key enzyme in the metabolic catabolism of fluoropyrimidines, such as 5-Fluorouracil and its oral prodrugs derivatives, including capecitabine and ftorafur (UFT, S1). Numerous genetic mutations have been identified in the DPD gene locus (DPYD), with a few variants having functional consequences on enzymatic activity. The allele frequency is 5% for heterozygoty and is 0.2% for homozygoty. It is correlated to the frequency of DPD activity deficiency that has been frequently reported to cause early severe, sometimes lethal fluoropyrimidine-related adverse events, regardless of the drug. Taking in account the wide and frequent use of fluoropyrimidines, both in advanced and adjuvant settings, it is clearly a problem of public healthcare that cannot be underestimated. We review in the present article the performances of assays that assess DPD and DPYD status, with an emphasis on their respective robustness and suitability for routine clinical applications. We show that DPD deficiency can be already detected primarily to treatment in practice and this detection could avoid life-threatening fluoropyrimidines toxic-side effects.

A phase III randomised trial of LV5FU2 + irinotecan versus LV5FU2 alone in adjuvant high-risk colon cancer (FNCLCC Accord02/FFCD9802).

BACKGROUND: This multicenter adjuvant phase III trial evaluated the addition of irinotecan to LV5FU2 in colon cancer patients at high risk of relapse. PATIENTS AND METHODS: A total of 400 patients with histologically proven primary colon cancer with postoperative N1 detected by occlusion/perforation or N2 were randomised to: A-LV5FU2 [leucovorin 200 mg/m(2), 2-h infusion, 5-fluorouracil (5-FU) 400 mg/m(2) bolus, 600 mg/m(2) 22-h continuous infusion, days 1 and 2] or B-LV5FU2 + IRI (irinotecan 180 mg/m(2) 90-min infusion day 1 + LV5FU2) fortnightly for 12 cycles. Primary end point was disease-free survival (DFS). RESULTS: Median follow-up was 63 months. Significantly more T4 tumours and 15 or more positive lymph nodes were observed in arm B. 5-FU relative dose intensity (RDI) was >0.80 for 94% and 77% in arms A and B, respectively (P < 0.001). Irinotecan RDI was >0.80 for 70% patients. There were more grades 3 and 4 neutropenia in arm B (4% versus 28%, P < 0.001). The 3-year DFS was 60% [95% confidence interval (CI) 53% to 66%] and 51% (95% CI 44% to 58) in arms A and B, respectively. No difference was observed [hazard ratio (HR) = 1.12, 95% CI 0.85-1.47, P = 0.42] even when adjusted for prognostic factors (adjusted HR = 0.98, 95% CI 0.74-1.31, P = 0.92). The 5-year overall survival (OS) was 67% (95% CI 59% to 73%) and 61% (95% CI 53% to 67%) in arms A and B, respectively. CONCLUSION: Adjuvant LV5FU2 + IRI compared with LV5FU2 alone in patients at high risk of relapse showed no improvement in DFS and OS.

Pharmacokinetic and pharmacogenetic determinants of the activity and toxicity of irinotecan in metastatic colorectal cancer patients.

This study aims at establishing relationships between genetic and non-genetic factors of variation of the pharmacokinetics of irinotecan and its metabolites; and also at establishing relationships between the pharmacokinetic or metabolic parameters and the efficacy and toxicity of irinotecan. We included 49 patients treated for metastatic colorectal cancer with a combination of 5-fluorouracil and irinotecan; a polymorphism in the UGT1A1 gene (TA repeat in the TATA box) and one in the CES2 gene promoter (830C>G) were studied as potential markers for SN-38 glucuronidation and irinotecan activation, respectively; and the potential activity of CYP3A4 was estimated from cortisol biotransformation into 6beta-hydroxycortisol. No pharmacokinetic parameter was directly predictive of clinical outcome or toxicity. The AUCs of three important metabolites of irinotecan, SN-38, SN-38 glucuronide and APC, were tentatively correlated with patients' pretreatment biological parameters related to drug metabolism (plasma creatinine, bilirubin and liver enzymes, and blood leukocytes). SN-38 AUC was significantly correlated with blood leukocytes number and SN-38G AUC was significantly correlated with plasma creatinine, whereas APC AUC was significantly correlated with plasma liver enzymes. The relative extent of irinotecan activation was inversely correlated with SN-38 glucuronidation. The TATA box polymorphism of UGT1A1 was significantly associated with plasma bilirubin levels and behaved as a significant predictor for neutropoenia. The level of cortisol 6beta-hydroxylation predicted for the occurrence of diarrhoea. All these observations may improve the routine use of irinotecan in colorectal cancer patients. UGT1A1 genotyping plus cortisol 6beta-hydroxylation determination could help to determine the optimal dose of irinotecan.

The influence of fluorouracil outcome parameters on tolerance and efficacy in patients with advanced colorectal cancer.

The purpose of this study was to determine simple genetic factors helpful to tailor 5-FU administration and determine strategy in first-line chemotherapy of advanced colorectal cancer. In 76 patients initially treated by 5-FU, thymidylate synthase, dihydropyrimidine dehydrogenase and methylene tetrahydrofolate reductase germinal polymorphisms, dihydrouracil/uracil plasma ratio and 5-FU plasma clearance were investigated and correlated for tolerance (10.5% grade 3 and 4 toxicity) and efficacy (32.9% objective response rate and 20 months median overall survival time). Toxicity was linked to performance status >2 (P=0.004), low UH2/U ratio, 2846 A>T, IVS 14+1G>A for DPD (P=0.031), and homozygoty C/C for MTHFR 1298 A>C (P=0.0018). The overall survival of the patients with a 3R/3R TS genotype associated with C/C for 677 C>T or A/A for 1298 A>C was statistically shorter (log-rank test P=0.0065). Genetic factors permit the tailoring of 5-FU treatment. They should occupy center stage in future clinical trials for specifically designing treatment for patients with a given biologic feature.

5-Fluorouracil-related severe toxicity: a comparison of different methods for the pretherapeutic detection of dihydropyrimidine dehydrogenase deficiency.

UNLABELLED: 5-Fluorouracil (5-FU)-related early toxicity, due to a metabolic deficiency, is rare but is potentially severe and even lethal (0.1%). It is due to dihydropyrimidine dehydrogenase (DPYD) gene polymorphism or some epigenetic factors. The detection of metabolic change could prevent severe toxicity, but until now it has not been carried out in clinical practice. PURPOSE: To find the simplest and most accurate pretherapeutic test to predict DPD deficiency in patients treated with 5-FU by comparing different approaches. RESULTS: Two hundred and fifty two French Caucasian patients treated by 5-FU infusion were studied. A two-step strategy, combining firstly SNP detection and uracil plasma measurement, followed, in cases where metabolic deficiency was suspected, by dihydrouracil/uracil ratio determination to confirm deficiency and to determine the optimum 5-FU dosage, appeared the best approach, with 83% and 82% sensitivity and specificity, respectively. CONCLUSION: These data support the future use of this approach, suitable to clinical practice, as screening test to identify DPD deficiency before 5-FU-based therapy.

Identification of a novel mutation in the dihydropyrimidine dehydrogenase gene in a patient with a lethal outcome following 5-fluorouracil administration and the determination of its frequency in a population of 500 patients with colorectal carcinoma.

OBJECTIVES: Life-threatening toxic side-effects following 5-FU exposure have been related to deficiency of dihydropyrimidine dehydrogenase (DPD), the rate-limiting enzyme in its catabolism. We presently report a new DPYD gene SNP in a Spanish woman who died from multivisceral 5-FU-induced toxicity. DESIGN AND METHODS: We looked for 22 known SNPs by Pyrosequecing. Then, we sequenced the whole 23 exons of DPYD, along with adjacent intronic sequences. PCR was carried out to determine whether or not exons were deleted in the DPYD. To determine whether the predicted stop codon indeed resulted in a truncated protein, a bacterial expression vector was employed to generate the predicted protein. 500 patients were genotyped to determine allele frequency. RESULTS: A novel mutation 464 T>A was identified in DPYD gene exon 5, resulting in the replacement of leucine 155 by a stop codon in the protein. We confirmed this mutation by Pyrosequencing and its involvement by a protein truncation test. We genotyped the patient's family and the allele frequency was 0.2%. CONCLUSION: The involvement of this variant in 5-FU life-threatening toxicity supports its inclusion in pretherapeutic genetic screening.

[Pharmacogenetics of anti-cancer drugs]. / Pharmacogénétique des anticancéreux.

Toxic side-effects of cytotoxic drugs is a stumbling-block of chemotherapy due to the fact that their therapeutic index is narrow. New approaches are necessary to individualize the treatments. Pharmacogenetic analysis is facilitated by easy access to the patient genome via simple blood samples, by the large number of known genes of interest coding for drugs targets or metabolism enzymes and by the fact that their polymorphism (SNP) is often known. Presently more focused on the prevention of toxic side-effects, pharmacogenetics already provides a good deal of confirmed data for clinical applications, such as the detection of dihydropyrimidine dehydrogenase deficiency by sequencing, or UGT1A1 7/7 genotype detection in Gilbert's syndrome for the prevention of 5-FU and irinotecan-induced severe toxicities. It must be emphasized that a SNP which is deleterious for enzyme activity is rarely a contraindication for the drug, provided that some precautions are taken and appropriate therapeutic advice is given by experts.

[Molecular pharmacogenetics in hospital laboratories in France: current data and future prospects]. / La pharmacogénétique moléculaire hospitalière en France: données actuelles et perspectives.

Molecular pharmacogenetic units have recently been established in several hospital laboratories in France. The clinical impact of these units is still limited and numerous problems of organizational, ethical, legal, technical, social and economical nature remain to be resolved. However, an increasing number of these units, a rise in their activities and an enlargement of their scope of application are foreseeable in the future. Ultimately, these units would significantly contribute to limit the public health problem caused by interindividual variabilities in drug effects. In view of these prospects, it seems essential that such hospital activity should be quickly recognised by the authorities and the various health sectors in France. It is also essential that the problems that arise from such pharmacogenetic activities should be considered by the authorities and would profit from the organization of a national network and from financial guarantees.

A Pharmacokinetic and Safety Study of Trebananib, an Fc-Fusion Peptibody, in Patients With Advanced Solid Tumors and Varying Degrees of Renal Dysfunction.

Clearance of trebananib (AMG 386), a 64-kD antiangiogenic peptibody, has been associated with estimated glomerular filtration rate (eGFR). We prospectively evaluated trebananib pharmacokinetics and safety/tolerability in advanced solid tumor patients with varying degrees of renal function. Patients were assigned to normal renal function, mild, moderate, or severe renal dysfunction cohorts based on eGFR, received trebananib 15 mg/kg i.v. weekly, and underwent week 1 and week 5 pharmacokinetic and weekly safety assessments. For 28 patients, trebananib clearance decreased from normal renal function (1.52 mL/hr/kg), to mild (1.20 mL/hr/kg), moderate (0.79 mL/hr/kg), and severe (0.53 mL/hr/kg) renal dysfunction (P ≤ 0.001). Treatment-related adverse events showed no association with clearance. Trebananib clearance was proportional to eGFR and unrelated to pretreatment protein excretion. These data confirm a role for renal clearance of a recombinant peptibody with molecular weight <69 kD and support a longer dosing interval for patients with severe renal dysfunction.

Gemcitabine combined with oxaliplatin in advanced pancreatic adenocarcinoma: final results of a GERCOR multicenter phase II study.

PURPOSE: Based on preclinical in vitro synergy data, this study evaluated the activity and toxicity of a gemcitabine/oxaliplatin combination in patients with metastatic and locally advanced pancreatic adenocarcinoma. PATIENTS AND METHODS: Previously untreated metastatic and locally advanced unresectable pancreatic adenocarcinoma patients were enrolled onto this multicenter phase II study. Patients received gemcitabine 1,000 mg/m(2) as a 10-mg/m(2)/min infusion on day 1 and oxaliplatin 100 mg/m(2) as a 2-hour infusion on day 2 every 2 weeks. Patients with metastatic disease were treated until evidence of progressive disease, whereas patients with locally advanced disease received six cycles in the absence of progression, followed when appropriate by concomitant radiochemotherapy. RESULTS: Among 64 eligible patients included in eight centers, 30 had locally advanced and 34 had metastatic disease. Response rate for the 62 patients with measurable disease was 30.6% (95% confidence interval, 19.7% to 42.3%), 31.0% for locally advanced and 30.3% for metastatic patients. Among 58 assessable patients, 40% had clinical benefit. Median progression-free survival and median overall survival (OS) were 5.3 and 9.2 months, respectively, with 36% of patients alive at 1 year. Median OS for patients with metastatic disease and locally advanced disease were 8.7 and 11.5 months, respectively. With 574 treatment cycles (median per patient, nine; range, zero to 27), grade 3/4 toxicity per patient was 11% for neutropenia and thrombocytopenia, 14% for nausea or vomiting, 6.2% for diarrhea, and 11% for peripheral neuropathy, with no toxic deaths. CONCLUSION: Palliative effects, response rate, and survival observed with this well-tolerated gemcitabine/oxaliplatin combination deserve additional evaluation. A comparative study of combination therapy versus gemcitabine alone is ongoing.

Correlation between uracil and dihydrouracil plasma ratio, fluorouracil (5-FU) pharmacokinetic parameters, and tolerance in patients with advanced colorectal cancer: A potential interest for predicting 5-FU toxicity and determining optimal 5-FU dosage.

PURPOSE: Patients with genetic fluorouracil (5-FU) catabolic deficiencies are at high risk for severe toxicity. To predict 5-FU catabolic deficiencies and toxic side effects, we conducted a prospective study of patients treated for advanced colorectal cancer by high-dose 5-FU. PATIENTS AND METHODS: Eighty-one patients were treated with weekly infusions of 5-FU and folinic acid. The initial 5-FU dose of 1,300 mg/m(2) was individually adjusted according to a dose-adjustment chart. Plasma concentrations of uracil (U) and its dihydrogenated metabolite, dihydrouracil (UH(2)), were measured before treatment, and the ratio of UH(2) to U was calculated. Pharmacokinetic and pharmacodynamic studies were conducted to look for a relationship between the ratio of UH(2) to U and 5-FU metabolic outcome and tolerance. RESULTS: The UH(2)-U ratios were normally distributed (mean value, 2.82; range, 0.35 to 7.13) and were highly correlated to (1) 5-FU plasma levels after the first course of treatment (r =.58), (2) 5-FU plasma clearance (r =.639), and (3) individual optimal therapeutic 5-FU dose (r =.65). Toxic side effects were observed only in patients with initial UH(2)-U ratios of less than 1.8. No adverse effects were noted in patients with UH(2)-U ratios of greater than 2.25. CONCLUSION: The UH(2)-U ratio, easily determined before treatment, could help to identify patients with metabolic deficiency and, therefore, a risk of toxicity.

Phase II study of oxaliplatin and fluorouracil in taxane- and anthracycline-pretreated breast cancer patients.

PURPOSE: Phase II study evaluating efficacy and safety of combined oxaliplatin/fluorouracil (5-FU) in taxane-pretreated advanced and metastatic breast cancer (ABC) patients. PATIENTS AND METHODS: Sixty-four taxane- and anthracycline-pretreated (within 6 months of study entry) women were treated with oxaliplatin 130 mg/m(2) (2-hour intravenous [IV] infusion), day 1, and 5-FU 1,000 mg/m(2)/d (continuous IV infusion) days 1 to 4, every 3 weeks. RESULTS: Median patient age was 51 years (range, 34 to 71 years), with a median of two involved organs (range, one to six organs), and metastases in the liver (70%), bone (47%), and lung (34%). Patients had a median of two prior chemotherapy regimens (range, one to six regimens), and 78% had previous hormonal therapy, with clinical taxane and anthracycline resistance in 53% and 34%, respectively. A total of 367 cycles were administered, with a median of six cycles/patient (range, one to 15 cycles). Sixty patients were assessable for response (World Health Organization criteria): 17 partial response, 26 stable disease, and 17 disease progression, giving an overall response rate of 27% (95% confidence interval, 16.3% to 39.1%), and 26% and 36% in taxane- and anthracycline-resistant populations, respectively, all responders having metastatic liver disease. Median time to progression was 4.8 months, and median overall survival was 11.9 months. Four treatment-related serious adverse events occurred, seven patients withdrew because of treatment-related toxicity. Hematotoxicity was prevalent but rarely severe, with grade 3-4 neutropenia, leukopenia, and thrombocytopenia in 34%, 19%, and 16% of patients, respectively, and a single episode of febrile neutropenia. One third of patients developed grade 2-3 peripheral neuropathy (oxaliplatin-specific scale), with grade 3 in only 8%. CONCLUSION: This oxaliplatin/5-FU combination is effective with an excellent safety profile in anthracycline/taxane-pretreated ABC patients, showing encouraging activity in patients with anthracycline/taxane-resistance or visceral disease.

Phase II study of oxaliplatin, fluorouracil, and folinic acid in locally advanced or metastatic gastric cancer patients.

PURPOSE: To evaluate the efficacy and safety of an oxaliplatin, fluorouracil (5-FU), and folinic acid (FA) combination in patients with metastatic or advanced gastric cancer (M/AGC). PATIENTS AND METHODS: Of the 54 eligible patients with measurable or assessable M/AGC, 53 received oxaliplatin 100 mg/m(2) and FA 400 mg/m(2) (2-hour intravenous infusion) followed by 5-FU bolus 400 mg/m(2) (10-minute infusion) and then 5-FU 3,000 mg/m(2) (46-hour continuous infusion) every 14 days. RESULTS: Patients (69% male, 31% female) had a median age of 61 years (range, 31 to 75 years), 89% had a performance status of 0 or 1, 70% had newly diagnosed disease, and 87% had metastatic disease. All had histologically confirmed adenocarcinoma. With a median of three involved organs, disease sites included the lymph nodes (67%), stomach (65%), and liver (61%). A median of 10 cycles per patient and 468 complete cycles were administered. Best responses in the 49 assessable patients were two complete responses and 20 partial responses, giving an overall best response rate of 44.9%. Eight patients underwent complementary treatment with curative intent (six with surgery and two with chemoradiotherapy). Median follow-up, time to progression, and overall survival were 18.6 months, 6.2 months, and 8.6 months, respectively. Grade 3/4 neutropenia, leukopenia, thrombocytopenia, and anemia occurred in 38%, 19%, 4%, and 11% of patients, respectively, and febrile neutropenia occurred in six patients (one episode each). Grade 3 peripheral neuropathy occurred in 21% of patients (oxaliplatin-specific scale). Seven patients withdrew because of treatment-related toxicity. CONCLUSION: This oxaliplatin/5-FU/FA regimen shows good efficacy and an acceptable safety profile in M/AGC patients, and may prove to be a suitable alternative regimen in this indication.

Randomized multicenter phase II study comparing a combination of fluorouracil and folinic acid and alternating irinotecan and oxaliplatin with oxaliplatin and irinotecan in fluorouracil-pretreated metastatic colorectal cancer patients.

PURPOSE: To assess antitumor activity and safety of two regimens in advanced colorectal cancer (CRC) patients with proven fluorouracil (5-FU) resistance in a randomized phase II study: 5-FU/folinic acid (FA) combined with alternating irinotecan (also called CPT-11) and oxaliplatin (FC/FO tritherapy), and an oxaliplatin/irinotecan (OC) combination. PATIENTS AND METHODS: Sixty-two patients were treated: arm FC/FO (32 patients) received, every 4 weeks, FA 200 mg/m(2) followed by a 400-mg/m(2) 5-FU bolus injection, then a 600-mg/m(2) continuous infusion of 5-FU on days 1 and 2 every 2 weeks administered alternately with irinotecan (180 mg/m(2) on day 1) and oxaliplatin (85 mg/m(2) on day 15). Arm OC (30 patients) received oxaliplatin 85 mg/m(2) and irinotecan 200 mg/m(2) every 3 weeks. RESULTS: In an intent-to-treat analysis, two partial responses lasting 10.7 and 16 months were observed with the tritherapy regimen, and seven (median duration, 11 months; range, 10.6 to 11.4 months) were observed with the bitherapy regimen. Median progression-free and overall survival times were 8.2 and 9.8 months, respectively, in the FC/FO arm and 8.5 and 12.3 months, respectively, in the OC arm. Main grade 3/4 toxicities were, respectively, neutropenia, 53% and 47%; febrile neutropenia, 13% and 3%; diarrhea, 19% and 10%; vomiting, 6% and 13%; and neurosensory toxicity, 3% and 3%. No treatment-related deaths occurred. CONCLUSION: The every-3-weeks OC combination is safe and active in advanced 5-FU-resistant CRC patients. The lower activity data seen with the tritherapy regimen may be related to the lower dose intensities of irinotecan and oxaliplatin in this schedule.

Long-term weekly treatment of colorectal metastatic cancer with fluorouracil and leucovorin: results of a multicentric prospective trial of fluorouracil dosage optimization by pharmacokinetic monitoring in 152 patients.

PURPOSE: A relationship between fluorouracil (5-FU) dose and response has been previously shown in advanced colorectal cancer. In a previous study with 5-FU stepwise dose escalation in a weekly regimen, and pharmacokinetic monitoring, we defined a therapeutic range for 5-FU plasma levels: 2,000 to 3,000 microg/L (area under the concentration-time curve at 0 to 8 hours [AUC0-8], 16 to 24 mg x h/L). The current study investigated 5-FU therapeutic intensification with individual dose adjustment in a multicentric phase II prospective trial. PATIENTS AND METHODS: Weekly high-dose 5-FU was administered by 8-hour infusion with 400 mg/m2 leucovorin. The initial dose of 5-FU (1,300 mg/m2) was adapted weekly according to 5-FU plasma levels, to reach the therapeutic range previously determined. RESULTS: A total of 152 patients entered the study from December 1991 to December 1994: 117 patients with measurable metastatic disease and 35 with assessable disease. Toxicity was mainly diarrhea (39%, with 5% grade 3) and hand-foot syndrome (30%, with 2% grade 3). Among 117 patients with measurable disease, 18 had a complete response (CR), 48 a partial response (PR), 35 a minor response (MR) and stable disease (SD), and 16 progressive disease (PD). Median overall survival time was 19 months. The 5-FU therapeutic plasma range was rapidly reached with a variable 5-FU dose in the patient population: mean, 1,803 +/- 386 mg/m2/wk (range, 950 to 3,396). Thirteen patients were immediately in the toxic zone, whereas 51 required a > or = 50% dose increase. CONCLUSION: Individual 5-FU dose adjustment with pharmacokinetic monitoring provided a high survival rate and percentage of responses, with good tolerance.

Clinical pharmacokinetics of oxaliplatin: a critical review.

Oxaliplatin (cis-[(1R,2R)-1,2-cyclohexanediamine-N,N'] oxalato(2-)-O,O'] platinum; Eloxatine) is a novel platinum coordination complex used for the treatment of metastatic colorectal carcinoma in combination with fluoropyrimidines. The objective of this review is to integrate the key data from multiple studies into a single, comprehensive overview of oxaliplatin disposition in cancer patients. The pharmacokinetics (PKs) of unbound platinum in plasma ultrafiltrate after oxaliplatin administration was triphasic, characterized by a short initial distribution phase and a long terminal elimination phase (t1/2, 252-273 h). No accumulation was observed in plasma ultrafiltrate after 130 mg/m2 every 3 weeks or 85 mg/m2 every 2 weeks. Interpatient and intrapatient variability in platinum exposure (area under the curve(0-48)) is moderate to low (33 and 5% respectively). In the blood, platinum binds irreversibly to plasma proteins (predominantly serum albumin) and erythrocytes. Accumulation of platinum in blood cells is not considered to be clinically significant. Platinum is rapidly cleared from plasma by covalent binding to tissues and renal elimination. Urinary excretion (53.8 +/- 9.1%) was the predominant route of platinum elimination, with fecal excretion accounting for only 2.1 +/- 1.9% of the administered dose 5 days postadministration. Tissue binding and renal elimination contribute equally to the clearance of ultrafilterable platinum from plasma. Renal clearance of platinum significantly correlated with glomerular filtration rate, indicating that glomerular filtration is the principal mechanism of platinum elimination by the kidneys. Clearance of ultrafilterable platinum is lower in patients with moderate renal impairment; however, no marked increase in drug toxicity was reported. The effect of severe renal impairment on platinum clearance and toxicity is currently unknown. Covariates such as age, sex, and hepatic impairment had no significant effect on the clearance of ultrafilterable platinum, and dose adjustment due to these variables is not required. Oxaliplatin undergoes rapid and extensive nonenzymatic biotransformation and is not subjected to CYP450-mediated metabolism. Up to 17 platinum-containing products have been observed in plasma ultrafiltrate samples from patients. These include several proximate cytotoxic species, including the monochloro-, dichloro-, and diaquo-diaminocyclohexane platinum complexes, along with several other noncytotoxic products. Oxaliplatin does not inhibit CYP450 isoenzymes in vitro. Platinum was not displaced from plasma proteins by a variety of concomitant medications tested in vitro, and no marked PK interactions between oxaliplatin, 5-fluorouracil, and irinothecan have been observed. These results indicate that the additive/synergistic antitumor activity observed with these agents is not due to major alterations in drug exposure, and the enhanced efficacy is likely to be mechanistically based. Together, these PK, biotransformation, drug-drug interaction analyses and studies in special patient populations provide a firm scientific basis for the safe and effective use of oxaliplatin in the clinic. These analyses also reveal that the pharmacological activity of oxaliplatin may be attributable, at least in part, to the unique pattern of platinum disposition observed in patients.

Cumulative pharmacokinetic study of oxaliplatin, administered every three weeks, combined with 5-fluorouracil in colorectal cancer patients.

The cumulative pharmacokinetic pattern of oxaliplatin, a new diamminecyclohexane platinum derivative, was studied in patients with metastatic colorectal cancer. Oxaliplatin was administered by i. v. infusion (130 mg/m2) over 2 h every 3 weeks, and 5-fluorouracil and leucovorin were administered weekly. A very sensitive method, inductively coupled plasma-mass spectrometry, allowed for the determination of total plasma and ultracentrifugable (UC) and RBC platinum levels on day 1, at 0, 2, and 5 h, and on days 8, 15, and 22. Sixteen patients underwent three or more courses, and six of them underwent six or more courses. The platinum concentration curves were quite similar from one course to another, with a high peak value 2 h after administration (day 1, Cmax = 3201 +/- 609 microgram/liter) and a rapid decrease (day 8, 443 +/- 99 microgram/liter). Cmax of both total and UC platinum levels in plasma remained unchanged throughout the treatment. The mean total platinum half-life in plasma was 9 days. We found residual levels of total platinum on day 22 (161 +/- 45 microgram/liter), but we observed no significant accumulation for the four first cycles (P = 0.57). In contrast, platinum accumulated significantly in RBCs after three courses (+91% at day 22 of the third cycle versus day 22 of the first cycle, P = 0.000018), and its half-life there was equivalent to that of RBCs. The patterns of UC and total platinum concentration curves were very similar and correlated significantly (P < 10(-6)) at all sampling times. The mean UC:total platinum ratio was 15% at day 1 and 5% at days 8, 15, and 22 in the 3-week treatment course. Unlike cisplatin, which rapidly accumulates in plasma as both free and bound platinum, oxaliplatin does not accumulate in plasma, but it does accumulate in RBCs, after repeated cycles at the currently recommended dose (130 mg/m2) and schedule of administration (every 3 weeks).

Dose and time dependencies of 5-fluorouracil pharmacokinetics.

OBJECTIVES: The purpose of this study was to examine the interpatient and intrapatient variability of the Michaelis-Menten plasma parameters of 5-fluorouracil administered according to a schedule combining a bolus of 400 mg/m2 followed by 22-hour infusion of 600 mg/m2 for 2 consecutive days. PATIENTS: A pharmacokinetic population approach was used to analyze the data from 21 patients with colorectal cancer. RESULTS: The 5-fluorouracil plasma concentrations versus time were best described by a two-compartment model with nonlinear elimination from the central compartment. The relationships between the pharmacokinetic parameters and patient characteristics were tested. On day 1 the mean values (with interindividual variability as expressed by the coefficient of variation) were 1390 mg x h(-1) (20%), and 5.57 mg x L(-1) (22%) for the maximum rate of elimination, and the half-saturating plasma concentration. The maximum rate of elimination was positively correlated to the body surface area and the percentage of liver involvement by metastatic disease determined by tomodensitometric examination. The model was successfully tested with independent data sets corresponding to other schedules. The analysis of this intrapatient variability showed that the half-saturating plasma concentration increased from day 1 to day 2, especially in the patients with low lymphocyte cell dihydropyrimidine dehydrogenase activity. CONCLUSION: The pharmacokinetic parameters obtained in this study would be useful to predict the 5-fluorouracil plasma concentrations following other schedules of administration of 5-fluorouracil and to study the possible pharmacokinetic interactions between 5-fluorouracil and other drugs.