Phase II trial of irinotecan in patients with metastatic colorectal carcinoma

90Y microsphere (TheraSphere) treatment for unresectable colorectal cancer metastases of the liver: response to treatment at targeted doses of 135-150 Gy as measured by [18F]fluorodeoxyglucose positron emission tomography and computed tomographic imaging

PURPOSE

The purpose of this phase II study was to determine the safety and efficacy of TheraSphere treatment (90Y microspheres) in patients with liver-dominant colorectal metastases in whom standard therapies had failed or were judged to be inappropriate.

MATERIALS AND METHODS

Twenty-seven patients with unresectable hepatic colorectal metastases were treated at a targeted absorbed dose of 135-150 Gy. Safety and toxicity were assessed according to the National Cancer Institute's Common Toxicity Criteria, version 3.0. Response was assessed with use of computed tomography (CT) and was correlated with response on [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET). Survival from first treatment was estimated with use of the Kaplan-Meier method.

RESULTS

Tumor response measured by FDG PET imaging exceeded that measured by CT imaging for the first (88% vs 35%) and second (73% vs 36%) treated lobes. Tumor replacement of 25% or less (vs >25%) was associated with a statistically significant increase in median survival (339 days vs 162 days; P = .002). Treatment-related toxicities included mild fatigue (n = 13; 48%), nausea (n = 4; 15%), and vague abdominal pain (n = 5; 19%). There was one case of radiation-induced gastritis from inadvertent deposition of microspheres to the gastrointestinal tract (n = 1; 4%). Three patients (11%) experienced ascites/pleural effusion after treatment with TheraSphere as a consequence of liver failure in advanced-stage metastatic disease. With the exception of these three patients whose sequelae were not considered to be related to treatment, all observed toxicities were transient and resolved without medical intervention.

CONCLUSION

TheraSphere administration appears to provide stabilization of liver disease with minimal toxicity in patients in whom standard systemic chemotherapy regimens have failed.

A phase II study of FOLFIRI-3 (double infusion of irinotecan combined with LV5FU) after FOLFOX in advanced colorectal cancer patients

In advanced colorectal cancer previously treated with oxaliplatin, efficacy of irinotecan-based chemotherapy is poor and the best regimen is not defined. We designed FOLFIRI-3 and conducted a phase II study to establish its efficacy and safety in advanced colorectal cancer patients previously treated with FOLFOX. FOLFIRI-3 consisted of irinotecan 100 mg m⁻² as a 60-min infusion on day 1, running concurrently with leucovorin 200 mg m⁻² as a 2-h infusion on day 1, followed by 46-h continuous infusion of 5-fluorouracil (5FU) 2000 mg m⁻², and irinotecan 100 mg m⁻² repeated on day 3, at the end of the 5FU infusion, every 2 weeks. Sixty-five patients entered the study. The intent-to-treat objective response rate was 23% (95% CI 13–33%). Disease was stable in 37% of patients, progressed in 26% and was not assessable in 14%. From the start of FOLFIRI-3, median progression-free survival was 4.7 months and median survival 10.5 months. Main toxicities (% of patients) were grade 3–4 diarrhoea 23% and grade 4 neutropenia 11%. FOLFIRI-3 is a promising regimen achieving high response rate and progression-free survival in patients previously treated with FOLFOX with a moderate toxicity.

Irinotecan in combination with thalidomide in patients with advanced solid tumors: a clinical study with pharmacodynamic and pharmacokinetic evaluation

PURPOSE

Recent clinical studies have demonstrated a reduction of irinotecan (CPT-11) gastrointestinal toxicities when the CPT-11 is administered in combination with thalidomide in patients with diagnosis of colorectal cancer. The main purpose of this study was to investigate possible interactions between CPT-11 pharmacokinetics and thalidomide to explain the previously described gastrointestinal toxicity reduction.

METHODS

In our clinical trial, advanced cancer patients were treated with CPT-11 on a dose of 350 mg/m2 at day 1 every 3 weeks. Only at the first cycle, CPT-11 was administered in association with thalidomide on a dose of 400 mg/day given from day 1 to day 14. From the second cycle, the treatment was continued with irinotecan alone at the same dose. Pharmacokinetics analysis of irinotecan and its metabolites, SN-38 and SN-38-glucuronide, were performed at the first and second cycle.

RESULTS

A total of 19 patients entered the study. The pharmacokinetic analysis were performed on 16 patients. Pharmacokinetic data suggested a decreased metabolism of irinotecan into SN-38 and SN-38-glucuronide when it was administered with thalidomide. Indeed, area under the time-concentration curve (AUC) of SN-38 was significantly lower at the first cycle than the second cycle (0.99+/-0.45 hxmicrog/ml vs 1.34+/-0.65, respectively, P=0.027) whereas AUC of irinotecan and SN-38-glucuronide were higher at first cycle than second cycle (34.53+/-11.38 hxmicrog/ml vs. 28.42+/-12.23 hxmicrog/ml, P=0.064 and 2.39+/-1.21 h(microg/ml vs. 1.86+/-1.11 hxmicrog/ml, P=0.018, respectively).

CONCLUSIONS

Our study demonstrates a significant decreased metabolism of CPT-11 into the active metabolite SN-38 when CPT-11 is administered in association with thalidomide. These observations strongly suggest an interaction of thalidomide with CPT-11 metabolism and, at least in part, it might explain the previously described improvement in tolerability.

A phase I dose-finding clinical pharmacokinetic study of an oral formulation of irinotecan (CPT-11) administered for 5 days every 3 weeks in patients with advanced solid tumours

BACKGROUND

Oral administration of irinotecan (CPT-11) should allow sustained exposure to the drug without the inconvenience of intravenous delivery and with fewer side-effects.

PATIENTS AND METHODS

The present phase I trial of CPT-11, administered orally as a powder-filled capsule for 5 consecutive days every 3 weeks at doses ranging from 30 to 90 mg/m(2)/day, was conducted in 47 patients for whom a satisfactory standard treatment option was no longer available (24 males/23 females; median age 51 years, range 26-85). Tumour types included melanoma (11), colorectal (4), urinary tract (3), lung/pleura (4), thyroid (3), liver (3), gallbladder (2), cervix/uterus (3), breast (2), pancreas (2), carcinoma and other cancer types (10).

RESULTS

A total of 171 cycles were administered (median 3, range 1-11). Dose limiting toxicities (DLTs) occurred during the first cycle in five of 31 patients in the dose-escalation part of the study: one patient at the 50 mg/m(2)/day dose level (diarrhoea grade 4); one patient at the 80 mg/m(2)/day dose level (prolonged neutropenia grade 4 and diarrhoea grade 3); and three patients at the 90 mg/m(2)/day dose level (diarrhoea, vomiting and neutropenia). The 80 mg/m(2)/day dose level was expanded, as a feasibility study, to include 16 additional patients, five of whom had received extensive prior pelvic irradiation. A further three patients in this cohort experienced DLTs, two of whom had received extensive prior pelvic irradiation. One patient died on study day 15 during the first cycle of oral CPT-11 following grade 3 diarrhoea, febrile neutropenia and a necrotic enterocolitis. Overall the grade 3/4 toxicities in 47 patients were asthenia (19%), anorexia (17%), neutropenia (14.9 %), diarrhoea (13%), nausea (12.7%), vomiting (8.5%) and thrombocytopenia (8.5%). Partial responses were observed in two melanoma patients and disease stabilisation was noted in 17 (36.1%) patients. Pharmacokinetic parameters were recorded for 46 patients.

CONCLUSIONS

At the maximum tolerated dose, defined as 80 mg/m(2)/day for 5 days every 3 weeks, oral CPT-11 was shown to be well tolerated and safe with few of the haematological toxicities associated with the intravenous formulation.

Single-agent irinotecan for recurrent/metastatic colorectal cancer: a retrospective analysis

OBJECTIVE

To evaluate the efficacy, toxicity and factors affecting the survival rate of patients treated with irinotecan.

SUBJECTS AND METHODS

Data from the medical records of 74 patients who had recurrent/metastatic colorectal cancer treated with single-agent irinotecan were analyzed.

RESULTS

The mean age for all the patients was 56 years (range 19-77). Forty-one (55%) and 33 (45%) patients had recurrent and/or metastatic colon cancer, respectively. All the patients were treated with irinotecan 350 mg/m(2) every 21 days. Grade 3-4 emesis, grade 3-4 diarrhea, grade 3-4 neutropenia and severe early cholinergic events developed in 7, 15, 7 and 1.3% of patients, respectively. One patient died due to acute renal failure. The overall response rate was 14% (complete response 5%, partial response 9%); 61% had stable response while another 25% had progressive disease. Patients with multiple metastatic foci, patients < or =50 years of age and patients with peritonitis carcinomatosa were shown to have worse outcomes than others. The median duration of response was 16.7 months. The median progression-free survival and overall survival were 4 and 14 months, respectively.

CONCLUSION

The data show that irinotecan was useful in the treatment of recurrent/metastatic colorectal cancer with acceptable toxicity.

Novel Single Nucleotide Polymorphism of UGT1A7 Gene in Japanese

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.

A phase II trial of irinotecan in patients with previously untreated advanced esophageal and gastric adenocarcinoma

Chemotherapy options for esophagogastric adenocarcinoma remain limited. Irinotecan has demonstrated broad activity in a variety of epithelial malignancies. Forty-six patients with previously untreated, measurable, unresectable, or metastatic esophagogastric adenocarcinoma were enrolled. Patients received irinotecan (125 mg/m2 intravenously over 90 min weekly) for 4 consecutive weeks followed by a 2-week rest. Forty-three patients received at least one treatment and were evaluable for response and toxicity. One complete and five partial responses were observed, for an overall response rate of 14% (95% CI, 4-24%). Median survival for all 43 patients was 6.4 months (95% CI, 4.6-8.2 months). Grade 3 to 4 toxicity included 10 patients (23%) with neutropenia, 13 patients (30%) with late diarrhea, 6 patients (14%) with vomiting, and 6 patients (14%) with fatigue. We conclude that although single-agent irinotecan is an active agent for esophagogastric adenocarcinoma, the schedule utilized in this trial is associated with moderate toxicity. When used as a single-agent, a tri-weekly schedule may be preferable for this patient population.

Pulmonary toxicity from novel antineoplastic agents

BACKGROUND

The pulmonary side-effects induced by novel antineoplastic agents have not been well characterized.

METHODS

To further investigate this topic, relevant English and non-English language studies were identified through Medline. For our search we used the generic names of novel cytotoxic or non-cytotoxic antineoplastic agents and the key phrases pulmonary/lung toxicity, dyspnea, pneumonitis, acute lung injury, acute respiratory distress syndrome and alveolar damage. The references from the articles identified were reviewed for additional sources. Abstracts from International Meetings were also included. Furthermore, information was obtained from the Pneumotox website, which provides updated knowledge on drug-induced respiratory disease as well as from pharmaceutical websites.

RESULTS

Most novel antineoplastic drugs may induce pulmonary toxicity, which involves mainly the parenchyma, and less frequently the airways, pleura or the pulmonary circulation. Furthermore, a subset of these agents impairs pulmonary function tests. The exact incidence of lung toxicity remains unclear. The most common patterns consist of dyspnea without further details and infiltrative lung disease (ILD), denoting changes in the interstitium or alveoli. The diagnosis is one of exclusion. ILD is usually benign and responds to appropriate treatment; however, fatalities have been reported.

CONCLUSIONS

Clinicians should be aware of the potential of most novel antineoplastic agents to cause lung toxicity. A high index of suspicion is required if these are combined with other cytotoxic drugs or radiation.

Phase I/II Dose-Escalation Study of Pemetrexed plus Irinotecan in Patients with Advanced Colorectal Cancer

BACKGROUND

Pemetrexed and irinotecan have demonstrated antitumor activity as single agents in lung, pancreatic, breast, and colorectal cancer (CRC). The distinct mechanisms of action and patterns of resistance displayed by pemetrexed and irinotecan make them attractive agents for combination therapy.

PATIENTS AND METHODS

This phase I/II, nonrandomized, open-labeled, single-arm study was composed of 3 segments. The initial phase II portion of the study enrolled 23 patients with advanced CRC who had received 1 previous dose of 5-fluorouracil (5-FU)-based chemotherapy for advanced disease. Because of poorer than anticipated efficacy, a phase I dose-escalation study using vitamin supplementation (n = 12) was added to the original protocol. The phase II dose-escalation portion of the study enrolled 36 patients (64% with previous oxaliplatin-based therapy) who received pemetrexed 500 mg/m2 followed by irinotecan 300 mg/m2 on day 1, every 21 days.

RESULTS

For the 35 evaluable patients in the phase II dose-escalation study, the objective response rate was 11.4% (95% confidence interval, 3.2%-26.7%); there was 1 patient with a complete response, 3 with partial responses, and 17 with stable disease. Three of four responders had received previous oxaliplatin-based combination therapy. Grade 3/4 hematologic toxicities included leukopenia (5.6%), anemia (2.8%), and thrombocytopenia (2.8%). Grade 3/4 nonhematologic toxicities included diarrhea (11.1%), increased aminotransferase levels (8.3%), nausea (8.3%), febrile neutropenia (5.6%), vomiting (5.6%), and reduced creatinine clearance (2.8%).

CONCLUSION

Pemetrexed plus irinotecan appears to be at least as active as FOLFIRI (leucovorin/5-FU/irinotecan) for second-line therapy of CRC following 5-FU-based combination chemotherapy. Further studies are warranted.

Effect of p53 Status and STAT1 on Chemotherapy-Induced, Fas-Mediated Apoptosis in Colorectal Cancer

We investigated the role of p53 and the signal transducer and activator of transcription 1 (STAT1) in regulating Fas-mediated apoptosis in response to chemotherapies used to treat colorectal cancer. We found that 5-fluorouracil (5-FU) and oxaliplatin only sensitized p53 wild-type (WT) colorectal cancer cell lines to Fas-mediated apoptosis. In contrast, irinotecan (CPT-11) and tomudex sensitized p53 WT, mutant, and null cells to Fas-mediated cell death. Furthermore, CPT-11 and tomudex, but not 5-FU or oxaliplatin, up-regulated Fas cell surface expression in a p53-independent manner. In addition, increased Fas cell surface expression in p53 mutant and null cell lines in response to CPT-11 and tomudex was accompanied by only a slight increase in total Fas mRNA and protein expression, suggesting that these agents trigger p53-independent trafficking of Fas to the plasma membrane. Treatment with CPT-11 or tomudex induced STAT1 phosphorylation (Ser727) in the p53-null HCT116 cell line but not the p53 WT cell line. Furthermore, STAT1-targeted small interfering RNA (siRNA) inhibited up-regulation of Fas cell surface expression in response to CPT-11 and tomudex in these cells. However, we found no evidence of altered Fas gene expression following siRNA-mediated down-regulation of STAT1 in drug-treated cells. This suggests that STAT1 regulates expression of gene(s) involved in cell surface trafficking of Fas in response to CPT-11 or tomudex. We conclude that CPT-11 and tomudex may be more effective than 5-FU and oxaliplatin in the treatment of p53 mutant colorectal cancer tumors by sensitizing them to Fas-mediated apoptosis in a STAT1-dependent manner.

In vitro and in vivo irinotecan-induced changes in expression profiles of cell cycle and apoptosis-associated genes in acute myeloid leukemia cells

OBJECTIVE

To study irinotecan (CPT-11)-induced changes in expression profiles of genes associated with cell cycle control and apoptosis in myeloid leukemia cells in vitro and in vivo.

METHODS

HL60 cells were exposed to clinically achievable concentrations of 7-ethyl-10-hydroxycamptothecin (SN-38), the active metabolite of CPT-11, and blood sampled from patients with acute myeloid leukemia and chronic myeloid leukemia in myeloid blast transformation treated with CPT-11. Gene expression changes were studied by cDNA microarray and correlated with biological responses by studying DNA distributions by flow cytometry.

RESULTS

cDNA microarray analysis showed down-regulation and up-regulation of specific cell cycle-associated genes, consistent with loss of S-phase cells and temporary delay of G(1)-S-phase transition seen by flow cytometry. Flow cytometry showed that cells in S phase during SN-38 exposure underwent apoptosis, whereas cells in G(2)-M and G(1) were delayed in G(1) and entered S phase only 6 to 8 hours after drug removal, consistent with the observed changes in gene expression. Proapoptotic changes in gene transcription included down-regulation of antiapoptotic genes and up-regulation of proapoptotic genes. Many gene expression changes observed following in vitro SN-38 exposure were also seen following in vivo administration of 10 or 15 mg/m(2) CPT-11; notably, proapoptotic changes included reduced transcription of survivin pathway-associated genes and increased transcription of death receptor 5.

CONCLUSION

CPT-11-induced changes in gene expression profiles in vitro and in vivo are consistent with temporary delay in G(1)-S transition and enhanced responsiveness to apoptosis, both of which may contribute to the synergistic interactions of this drug with antimetabolites.

Prognostic impact of race and ethnicity in the treatment of colorectal cancer

Numerous advances in the treatment of patients who have metastatic disease have improved colorectal cancer management, including new chemotherapeutic agents and combinations and targeted agents that modulate the efficacy of chemotherapy. Recent advances in the administration of irinotecan and oxaliplatin, in combination with 5-FU/LV, plus the addition of targeted agents bevacizumab and cetuximab have afforded steady increases in response rates and survival. Ongoing studies are evaluating the optimal sequencing and combinations of the agents described and the efficacy of new combinations in metastatic and adjuvant settings. Because the number of African-American patients in most clinical trials in colorectal cancer has been low, it is imperative that method increase participation so that new research developments reach all segments of the population.

Benefit-risk assessment of irinotecan in advanced colorectal cancer

Irinotecan exerts its cytotoxic activity through inhibition of the nuclear enzyme topoisomerase I. It has been approved in most countries worldwide for treatment of patients with advanced colorectal cancer (CRC). Activity is seen in previously untreated patients and in patients refractory to fluorouracil treatment, whether it is given alone or in combination with other cytotoxic drugs. Irinotecan was first developed in patients refractory to fluorouracil. Activity in terms of tumour responses and patient benefit was seen in several phase II trials that used either a weekly or a three-weekly schedule. In two randomised trials (irinotecan vs best supportive care, and irinotecan vs an infused fluorouracil-based regimen), irinotecan prolonged median survival by approximately 2.5 months without any deterioration in quality-of-life. It was later studied in previously untreated patients with advanced CRC in combination with fluorouracil/folinic acid (leucovorin). In three large randomised trials, median time to tumour progression was prolonged by approximately 2.5 months and overall survival by about 2.5 months compared with fluorouracil/folinic acid alone. Tumour responses were also seen more frequently in the irinotecan arm (35-40% vs 20%). Again, quality-of-life scores were not deteriorated by the addition of irinotecan. Irinotecan has many acute adverse effects. The most prominent and dose limiting being diarrhoea and neutropenia. With irinotecan monotherapy, diarrhoea was seen in 80% of patients and severe grade 3 to 4 diarrhoea occurred in 30-40% of the patients. The severity of diarrhoea can be diminished by preventive actions. Less risk of diarrhoea is generally seen when irinotecan is combined with fluorouracil. Neutropenia is generally short-lived, but may be severe if diarrhoea is also present. This has been noticed particularly when irinotecan has been given in combination with a bolus fluorouracil/folinic acid regimen. Other toxicities include acute cholinergic-like symptoms, nausea and vomiting, and alopecia. In spite of these adverse effects, irinotecan has been accepted as an important first-line treatment for patients with advanced CRC, in combination with, preferably, an infused fluorouracil-based regimen, and has been approved for use as monotherapy in the second-line indication.

Phase II trial of fortnightly irinotecan (CPT-11) in the treatment of colorectal cancer patients resistant to previous fluoropyrimidine-based chemotherapy

INTRODUCTION

This phase II study investigated the anti-tumour activity and toxicity of CPT-11 (250 mg/m2 i.v. infusion over 60 minutes) administered every 2 weeks as second-line chemotherapy in patients with advanced colorectal cancer (CRC).

MATERIAL AND METHODS

Patients (n = 63) with histology diagnosis of advanced CRC and proven resistance to previous fluoropyrimidine therapy were enrolled.

RESULTS

A total of 510 CPT-11 cycles were administered, with a mean of 8 cycles per patient (range: 1-32). The median relative dose intensity was 93%. Partial response (PR) was obtained in 11 patients (17.5%; 95%CI: 8.1%-26.7%) and 29 patients (46.0%) showed stable disease (clinical benefit of 63.5%). The median duration of response was 6.8 months (95%CI: 6.1-7.5 months), median survival was 8.8 months (95%CI: 6.3-11.5 months) and median time to disease progression was 4.5 months (95%CI: 3.9-5.0 months). Overall, this schedule of CPT-11 chemotherapy was well tolerated by the patient. Neutropenia was the most frequent grade 3/4 haematological toxicity (20.6% of patients and 4.1% of cycles). Neutropenia with concurrent fever or infection occurred in 7 patients (11.1%). Late onset diarrhoea was the most frequent grade 3/4 non-haematological toxicity (19.0% of patients and 2.3% of cycles). Other, lower-incidence, toxicities were anaemia, fever, infection, mucositis, nausea and vomiting. There were no toxic deaths.

CONCLUSIONS

We found that CPT-11, administered as 250 mg/m2 i.v. infusion over 60 minutes every 2 weeks, was active and well tolerated schedule in the second-line chemotherapy of advanced CRC patients. This bi-weekly scheme could be used as an alternative to the weekly or the every-three-week schedule as well as in combined therapies with other chemotherapeutic agents for the treatment of advanced, metastatic, CRC.

Gene expression profiling of the irinotecan pathway in colorectal cancer

The exact mechanism responsible for large variation of response to chemotherapy remains unclear. This study profiled the gene expression for the entire irinotecan pathway to provide insights into individualized cancer therapy. The RNA expressions of 24 irinotecan pathway genes were measured in paired tumor and normal tissues from 52 patients with Dukes' C colorectal cancer using a real-time quantitative reverse transcription-PCR assay. The relative expression levels across the 24 pathway genes varied considerably, with a 441-fold range from highest to lowest expression levels for the tumor tissues and a 934-fold range for the normal tissues. Interpatient variability was also quite large, with a 33.6 median fold change in the tumor tissue genes and a 30.1 median fold change in the normal tissue genes. Six of the 24 irinotecan pathway genes had dramatically lower expression levels in the tumor samples than did the genes in the normal tissues (median range, 1.28-4.39 folds; P = 0.001-0.029). Eight genes had significantly higher levels (median range, 1.35-2.42 folds; P = 0.001-0.011). Using hierarchical clustering, three gene clusters and three patient groups were observed with high similarity indices by the RNA expressions in colorectal tumors. The three patient groups had no unique clinical pathologic features but could be differentiated by the statistically significant differences in RNA expression level of seven genes. Our study indicates that gene expression profiling could be valuable for predicting tumor response to chemotherapy and for tailoring therapy to individual cancer patients.

Phase II study of irinotecan, 5-fluorouracil and leucovorin as first-line therapy for advanced colorectal cancer

BACKGROUND

We evaluated the efficacy and tolerability of a modified biweekly irinotecan, 5-fluorouracil and leucovorin regimen (modified Douillard regimen) as the first-line therapy in patients with advanced colorectal cancer.

METHODS

A total of 80 patients (41 male, 39 female) with recurrent or metastatic colorectal cancer were enrolled between April 2001 and December 2003. The treatment cycle consisted of irinotecan 150 mg/m(2) as a 90 min infusion on day 1, leucovorin 20 mg/m(2) intravenous bolus, immediately followed by a 48 h continuous infusion of 5-fluorouracil 3000 mg/m(2) on day 1. The primary end-point was response rate, and the secondary end-points were time to progression and toxicity profile.

RESULTS

An overall objective response rate of 38.7% [95% confidence interval (CI) 27.84-49.66%] was achieved. The median time to progression was 6.1 months (95% CI 4.63-7.57 months) and the median overall survival time was 20.2 months (95% CI 15.50-24.90 months). The median duration of follow-up for patients was 16.9 months. The toxicity profile was more favorable than for the conventional Douillard regimen.

CONCLUSION

We conclude that the modified Douillard regimen may be a practical and more tolerable treatment option in patients with advanced colorectal cancer.

Phase III study of weekly high-dose infusional fluorouracil plus folinic acid with or without irinotecan in patients with metastatic colorectal cancer: European Organisation for Research and Treatment of Cancer Gastrointestinal Group Study 40986

PURPOSE

To demonstrate that adding irinotecan to a standard weekly schedule of high-dose, infusional fluorouracil (FU) and leucovorin (folinic acid [FA]) can prolong progression-free survival (PFS).

PATIENTS AND METHODS

Four hundred thirty patients with measurable or assessable metastatic colorectal cancer were randomly assigned to receive either FA 500 mg/m(2) as a 2-hour infusion and FU 2.6 g/m(2) by intravenous 24-hour infusion, both administered weekly for 6 weeks, followed by a 2-week rest (Arbeitsgemeinschaft für Internistische Onkologie [AIO] arm, n = 216), or a similar schedule but with FU 2.3 or 2.0 g/m(2) preceded by irinotecan 80 mg/m(2) administered over 30 minutes (experimental group, n = 214).

RESULTS

The median PFS time in the experimental group was 8.5 months (95% CI, 7.6 to 9.9 months) compared with 6.4 months (95% CI, 5.3 to 7.2 months) in the AIO arm (P < .0001). The median overall survival time was increased from 16.9 to 20.1 months (P = .2779). The objective response rate was 62.2% (95% CI, 55.0% to 69.5%) in the experimental group and 34.4% (95% CI, 27.5% to 41.3%) in the AIO arm (P < .0001).

CONCLUSION

The addition of irinotecan to the standard AIO FU/FA regimen was associated with a highly significant improvement in PFS and response rate and was well tolerated. The results of this study confirm that irinotecan in combination with high-dose infusional FU/FA is a reference first-line treatment.

The irinotecan/5-fluorouracil combination induces apoptosis and enhances manganese superoxide dismutase activity in HT-29 human colon carcinoma cells

BACKGROUND

We examined whether induction of apoptosis and Mn-superoxide dismutase (Mn-SOD) and Cu,Zn-superoxide dismutase (Cu,Zn-SOD) activities were involved in the greater cytotoxicity of the irinotecan (CPT-11)/5-fluorouracil (5-FU) combination for human colon cancer cells when compared to both drugs alone.

METHODS

HT-29 and SNU-C4 human colon carcinoma cell lines were treated with 5-FU and CPT-11, then apoptosis was evaluated by flow cytometry and SOD activities were determined by polyacrylamide gel electrophoresis.

RESULTS

Enhanced apoptosis of HT-29 cells was observed with all treatments containing 5-FU in SNU-C4 cells; however, in HT-29 cells, apoptosis was enhanced only with the CPT-11/5-FU combination. In the SNU-C4 cell line, none of the treatments exerted a significant effect on Cu,Zn-SOD or Mn-SOD activity. However, in HT-29 cells, the CPT-11/5-FU combination enhanced Mn-SOD activity when compared to cells treated with CPT-11 alone. Nevertheless, the combined treatment did not interfere with Cu,Zn-SOD activity.

CONCLUSION

Treatment with the CPT-11/5-FU combination may promote in HT-29 cell apoptosis by enhancing Mn-SOD activity.

Optimisation of irinotecan dose in the treatment of patients with metastatic colorectal cancer after 5-FU failure: results from a multinational, randomised phase II study

Although irinotecan 350 mg m⁻² is a standard option for relapsed/refractory advanced colorectal cancer, there is some evidence that suggests that a higher dose may be more effective, with acceptable tolerability, following 5-fluorouracil (5-FU). This study assessed the optimal dosing strategy for irinotecan, along with treatment efficacy and safety. A total of 164 patients with metastatic colorectal cancer progressing after failure on 5-FU or raltitrexed received either 350 mg m⁻² irinotecan (Group A; n=36) or 250, 350 or 500 mg m⁻², according to individual patient tolerance (Group B; n=62) or based on risk factor optimisation (Group C; n=66). There were no complete responses. There was a trend towards a higher overall response rate in Group B (13%) than in Groups A (8%) and C (9%). Tumour control growth rate was high in all three groups: 58% in group A, 60% in Group B and 50% in Group C. A total of 34% of patients in Group B and 9% in Group C were able to receive a dose of 500 mg m⁻². Median duration of response and time to progression were significantly longer in Groups A and B compared with Group C. No significant between-group differences for any adverse events were seen, although there was a small trend towards better tolerability in Group B. Individual dose escalation based on patient tolerance may allow more patients to receive a higher irinotecan dose without causing additional toxicity and can be an appropriate patient management strategy.

The novel highly lipophilic topoisomerase I inhibitor DB67 is effective in the treatment of liver metastases of murine CT-26 colon carcinoma

Colorectal carcinoma occurs in 1 of 20 individuals in most developed countries. The relapse after resection with metastatic liver disease is a major cause of death. 7-t-Butyldimethylsilyl-10-hydroxycamptothecin (DB67) has been incorporated into liposomes allowing for intravenous (i.v.) administration. A preclinical efficacy study of liposomal DB67 was performed using the colon carcinoma CT-26 cell line. The therapeutic dose for DB67 and liposomal DB67 was found to be 7 mg/kg per day using the qdx5/1 schedule. The results are compared with those obtained with irinotecan. The treatment with liposomal DB67 administered intravenously was more effective in reducing the weight and volume of primary spleen tumors and the weight and extent of liver metastases than free DB67 or liposomal DB67 administered intraperitoneally, but less effective than irinotecan. When the primary tumor was resected, treatment with liposomal DB67 administered intravenously was more effective in reducing the weight and extent of liver metastases than DB67 or liposomal DB67 administered intraperitoneally, and irinotecan. DB67 showed a higher accumulation in spleen and liver after its i.v. administration in liposomal form compared with its free or liposomal form administered intraperitoneally. DB67 and liposomal DB67 are more effective than irinotecan in the treatment of liver metastases after resection of the primary tumor.

Phase I clinical and pharmacokinetic trial of docetaxel and irinotecan administered on a weekly schedule

BACKGROUND

Docetaxel and irinotecan are synergistic agents with a broad spectrum of activity but overlapping myelosuppression. The study was designed to maintain dose intensity while limiting myelosuppression. The objectives of this study were to determine the maximal tolerated dose (MTD) of the combination of docetaxel and irinotecan administered weekly for four consecutive weeks every 42 days, to describe toxicities of this regimen, and to perform a pharmacokinetic analysis to evaluate changes in drug disposition as a function of dose as well as repeated dosing.

METHODS

Adult patients with advanced solid tumors were treated with docetaxel followed by irinotecan. Doses of 30/50, 35/50, 35/66, 30/57, 30/65, 30/80 mg/m(2), respectively, were studied. Pharmacokinetics of docetaxel, irinotecan and SN-38 in plasma were determined on days 1 and 22 by a high-performance liquid chromatography (HPLC) assay.

RESULTS

A total of 35 patients were treated. The MTD was docetaxel 30 mg/m(2) plus irinotecan 65 mg/m(2). Diarrhea was the dose-limiting toxicity; myelosuppression and other non-hematological toxicities were uncommon and mild. There were no significant differences in pharmacokinetic parameters between day 1 and day 22 (n=20). Five objective responses (breast, stomach and unknown primary) were observed among 30 evaluable patients. In addition, eight patients achieved stable disease.

CONCLUSIONS

The combination of weekly docetaxel and irinotecan is a well tolerated regimen and should be explored in phase II trials. This schedule maintains dose intensity and has limited myelosuppression.

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.

Prevention of Irinotecan-Induced Diarrhea by Oral Sodium Bicarbonate and Influence on Pharmacokinetics

Alkalization of the intestinal tract by oral administration of sodium bicarbonate has been reported to be a promising method for preventing delayed diarrhea, a dose-limiting toxicity in patients receiving chemotherapy with irinotecan hydrochloride. However, it is feared that this method may adversely affect the pharmacokinetics of irinotecan by inhibiting its intestinal absorption and that of its active metabolites. We compared the pharmacokinetics and toxicity of irinotecan with and without oral alkalization in a cross-over study that enrolled 10 colorectal cancer patients. We found that alkalization did not decrease the blood levels of irinotecan and its active metabolite. In fact, the area under concentration versus time curves (AUCs) of irinotecan and 7-ethyl-10-hydroxycamptothecin glucuronide (SN-38G) were statistically equivalent both with and without oral alkalization. Also, the AUC of SN-38 with alkalization was statistically equivalent or larger than that without alkalization. Oral alkalization reduced the incidence of diarrhea and gastrointestinal symptoms, and these adverse effects were not worsened by long-term administration. These results suggest that oral alkalization can control diarrhea and gastrointestinal toxicity without decreasing the blood levels of irinotecan and its active metabolites, thus improving the tolerability of long-term chemotherapy without reducing efficacy.

Proteasomal Degradation of Topoisomerase I Is Preceded by c-Jun NH2-Terminal Kinase Activation, Fas Up-Regulation, and Poly(ADP-Ribose) Polymerase Cleavage in SN38-Mediated Cytotoxicity against Multiple Myeloma

Topoisomerase I inhibitors are effective anticancer therapies and have shown activity in hematologic malignancies. Here we show for the first time that SN38, the potent active metabolite of irinotecan, induces c-Jun NH(2)-terminal kinase activation, Fas up-regulation, and caspase 8-mediated apoptosis in multiple myeloma (MM) cells. Proteasomal degradation of nuclear topoisomerase I has been proposed as a resistance mechanism in solid malignancies. SN38-induced proteasomal degradation of topoisomerase I was observed during SN38-mediated cytotoxicity against MM.1S myeloma cell line but occurred after c-Jun NH(2)-terminal kinase activation, Fas up-regulation, and poly(ADP-ribose) polymerase cleavage and failed to protect cells from apoptosis. Differential toxicity was observed against MM cells versus bone marrow stromal cells, and SN38 inhibited adhesion-induced up-regulation of MM cell proliferation when MM cells adhere to bone marrow stromal cells. In addition, SN38 directly inhibited constitutive and inducible interleukin 6 and vascular endothelial growth factor secretion by bone marrow stromal cells. Synergy was observed when SN38 was used in combination with doxorubicin, bortezomib, as well as poly(ADP-ribose) polymerase inhibitor NU1025 and Fas-activator CH11. These findings have clinical significance, because identification of downstream apoptotic signaling after topoisomerase I inhibition will both elucidate mechanisms of resistance and optimize future combination chemotherapy against MM.

Randomised phase 2 trial of SIR-Spheres plus fluorouracil/leucovorin chemotherapy versus fluorouracil/leucovorin chemotherapy alone in advanced colorectal cancer

PURPOSE

Selective internal radiation therapy (SIRT) with SIR-Spheres(R) is a new technique for selectively targeting high doses of radiation to tumours within the liver. The primary objectives of this randomised trial were to compare the response rate, time to progressive disease (PD), and toxicity of a regimen of systemic fluorouracil/leucovorin chemotherapy versus the same chemotherapy plus a single administration of SIR-Spheres in patients with advanced colorectal liver metastases. The trial was designed to presage a larger trial that would have survival as the primary outcome.

PATIENTS AND METHODS

Twenty-one patients with previously untreated advanced colorectal liver metastases, with or without extrahepatic metastases, were randomised into the study.

RESULTS

Using RECIST criteria, the response rate for 11 patients receiving the combination treatment was significantly greater than for 10 patients receiving chemotherapy alone (First Integrated Response; 10 PR, 1 SD vs. 0 PR, 6 SD, 4 PD, P < 0.001 and Best Confirmed Response; 8 PR, 3 SD vs. 0 PR, 6 SD, 4 PD P < 0.001). The time to PD was greater for patients receiving the combination treatment (18.6 months vs. 3.6 months, P < 0.0005). Median survival was significantly longer for patients receiving the combination treatment (29.4 months vs. 12.8 months, P = 0.02). One patient in the combination arm died from chemotherapy induced neutropenic sepsis after the fourth chemotherapy cycle. There were more Grade 3 and 4 toxicity events in patients receiving the combination treatment. There was no difference in quality-of-life over a 3 month period between the two treatments when rated by patients (P = 0.96) or physicians (P = 0.98).

CONCLUSIONS

This small phase 2 randomised trial demonstrated that the addition of a single administration of SIR-Spheres to a regimen of systemic fluorouracil/leucovorin chemotherapy significantly increased both treatment related response, time to PD, and survival with acceptable toxicity. The combination of SIR-Spheres plus systemic chemotherapy is now the subject of ongoing trials to further define patient benefit.

Phase I dose-escalation trial of irinotecan with continuous infusion 5-FU first line, in metastatic colorectal cancer

This single-centre phase I trial was designed to determine the maximum tolerated dose of irinotecan and the recommended dose to use in combination with a fixed dose of 5-fluorouracil (5-FU) administered as a protracted venous infusion, for the first-line treatment of metastatic colorectal cancer (CRC). Tolerability and efficacy were secondary end points. In all, 22 patients, median age 57 years, were treated with escalating, weekly doses of irinotecan (50, 75, 100 and 85 mg m⁻²) in combination with 250 mg m⁻² 5-FU administered as a continuous infusion. All patients had measurable disease. The combination was well tolerated up to an irinotecan dose of 75 mg m⁻². However, three out of five patients at the 100 mg m⁻² irinotecan dose level had their dose reduced due to multiple grade 2 toxicities, and eventually one patient stopped treatment due to grade 3 diarrhoea and multiple grade 2 toxicities. Subsequent patients were recruited at an irinotecan dose level of 85 mg m⁻². The overall response rate was 55%, comprising one complete and 11 partial responses (PRs). Six patients also achieved sustained stable disease (SD), giving a clinical benefit (complete response/PR/SD) response of 82%. The median duration of response was 238 days (8.5 months) and median time to progression was 224 days (8.0 months). Two patients who achieved PRs underwent partial hepatectomies. Thus, irinotecan (85 mg m⁻²) combined with a continuous infusion of 5-FU (250 mg m⁻²) is an active and well-tolerated regimen for the treatment of metastatic CRC. It represents an effective treatment for patients who require close supervision and support, throughout their initial exposure to chemotherapy for this disease, and this dose combination was recommended for an ongoing phase II study.

Phase I study of an oral formulation of irinotecan administered daily for 14�days every 3�weeks in patients with advanced solid tumours

A phase I study was conducted with oral irinotecan given daily for 14 days every 3 weeks in 45 patients with solid tumours to establish the maximum tolerated dose (MTD), toxicity, preliminary antitumour response and pharmacokinetics. Irinotecan was administered orally as a powder-filled capsule at doses ranging from 7.5 to 40 mg/m2 per day. Tumours were predominantly colorectal (30) together with 10 other gastrointestinal, 2 breast, 2 small cell lung and 1 ovarian. All but three patients had received prior chemotherapy. The median number of administered cycles was 3 (range 1-19). Gastrointestinal toxicities (grade 3 nausea, grade 3/4 vomiting and diarrhoea) and one incidence of grade 3 asthenia were dose limiting. There were no grade 3/4 haematological toxicities. The MTD was 30 mg/m2 per day. There were two documented partial responses, one in a patient with cancer of the small intestine and the other in a patient with colon cancer. Stable disease was seen in 16 patients (35.5%). Peak concentrations of irinotecan and metabolite SN-38 were reached within 2.0-2.4 h. The metabolic ratio of SN-38 AUC to irinotecan AUC was 0.17+/-0.10 (mean+/-SD). The dose recommended for phase II studies is 30 mg/m2 per day administered daily for 14 days every 3 weeks.

Multicentre phase II study of bifractionated CPT-11 with bimonthly leucovorin and 5-fluorouracil in patients with metastatic colorectal cancer pretreated with FOLFOX

This multicentre phase II study was designed to evaluate the antitumour activity and toxicity of bifractionated camptothecin (CPT-11) and 5-fluorouracil/ leucovorin (5-FU/LV) in the treatment of patients with metastatic colorectal cancer (MCC) who had been pretreated with 5-FU/LV-oxaliplatin (FOLFOX regimen). In all, 35 patients were enrolled in a two-stage trial. Treatment consisted of two daily doses of CPT-11, 90 mg m2 administered over 90 min, followed by LV, 200 mg m2 administered over 2 h plus 5-FU 400 mg m2 as a bolus and 600 mg m2 as a 22-h continuous infusion administered with disposable pumps as outpatient therapy. Toxicity was closely monitored. Response was evaluated by computed tomography scans every 8 weeks. All 35 patients were assessable for toxicity and response to treatment. Seven patients had a partial response, giving an overall response rate of 20%; 11 patients had stable disease (31.4%) and 17 progressed (48.5%). The median progression-free survival was 7.1 months and median survival was 14 months. A total of 10 patients (30%) experienced grade 3-4 toxicity, including nausea (15%), diarrhoea (12%) and neutropenia (15%), while seven patients (21%) had grade 2 alopecia. The bifractionated bimonthly schedule of CPT-11 plus 5-FU/LV showed substantial antitumour activity and was well tolerated in this group of patients with a poor prognosis, pretreated with the FOLFOX regimen.

A phase I, dose-finding study of irinotecan (CPT-11) short i.v. infusion combined with fixed dose of 5-fluorouracil (5-FU) protracted i.v. infusion in adult patients with advanced solid tumours

PURPOSE

Irinotecan (CPT-11) and 5-fluorouracil (5-FU) are effective cytotoxic agents in the treatment of solid tumours. Continuous i.v. infusion (CI) of 5-FU is significantly more active and better tolerated than bolus i.v. 5-FU. This phase I pharmacokinetic and clinical study evaluated escalating CPT-11 doses administered every 3 weeks combined with a fixed dose of 5-FU CI over 14 days to find the maximum tolerated dose (MTD) of this combined chemotherapy.

PATIENTS AND METHODS

Patients with solid tumours showing failure with previous standard treatment or for whom no established curative therapy existed received CPT-11 i.v. over 90 min (six dose levels were evaluated: 150, 175, 200, 250, 300 and 350 mg/m(2)) plus a fixed dose of 5-FU CI 250 mg/m(2) per day over 14 days. If the MTD was not reached at CPT-11 level 6, then 5-FU was increased to 300 mg/m(2). In step 2, 5-FU was administered as a true protracted infusion at the recommended dose found during step 1. In step 3, the recommended dose of CPT-11 was divided and administered in a weekly schedule for 4 weeks combined with a fixed dose of 5-FU CI 250 mg/m(2), and then followed by 2-5 weeks rest.

RESULTS

Neutropenia and diarrhoea were the main toxicities, leading to early termination of infusion in three of six patients in level 7. Therefore, CPT-11 350 mg/m(2) + 5-FU 250 mg/m(2) CI over 14 days was identified as the recommended dose. In step 2, CPT-11 dose had to be reduced to 300 mg/m(2) due to toxicity. The weekly schedule of CPT-11 75 mg/m(2) + 5-FU 250 mg/m(2) CI was feasible with only one patient experiencing severe diarrhoea. No interactions were found in the kinetics parameters of CPT-11 or 5-FU for the different dose levels studied.

CONCLUSION

CPT-11 300 mg/m(2) + 5-FU 250 mg/m(2) protracted infusion is the recommended dose for phase II trials, neutropenia and diarrhoea being the dose-limiting toxicities.

A randomised phase II multicentre trial of irinotecan (CPT-11) using four different schedules in patients with metastatic colorectal cancer

The purpose of this phase II trial was to compare the efficacy, safety and pharmacokinetics of four irinotecan schedules for the treatment of metastatic colorectal cancer. In total, 174 5-fluorouracil pretreated patients were randomised to: arm A (n=41), 350 mg m(-2) irinotecan as a 90-min i.v. infusion q3 weeks; arm B (n=38), 125 mg m(-2) irinotecan as a 90-min i.v. infusion weekly x 4 weeks q6 weeks; arm C (n=46), 250 mg m(-2) irinotecan as a 90-min i.v. infusion q2 weeks; or arm D (n=49), 10 mg m(-2) day(-1) irinotecan as a 14-day continuous infusion q3 weeks. No significant differences in efficacy across the four arms were observed, although a shorter time to treatment failure was noted for arm D (1.7 months; P=0.02). Overall response rates were in the range 5-11%. Secondary end points included median survival (6.4-9.4 months), and time to progression (2.7-3.8 months) and treatment failure (1.7-3.2 months). Similarly, there were no significant differences in the incidence of grade 3-4 toxicities, although the toxicity profile between arms A, B, and C and D did differ. Generally, significantly less haematologic toxicity, alopecia and cholinergic syndrome were observed in arm D; however, there was a trend for increased gastrointestinal toxicity. Irinotecan is an effective and safe second-line treatment for colorectal cancer. The schedules examined yielded equivalent results, indicating that there is no advantage of the prolonged vs short infusion schedules.

Phase II study of irinotecan (CPT-11) administered every 2 weeks as treatment for patients with colorectal cancer resistant to previous treatment with 5-fluorouracil-based therapies: comparison of two different dose schedules (250 and 200 mg/m2) according to toxicity prognostic factors

Our objective was to assess the antitumoral activity and toxicity of irinotecan (CPT-11) 60-min i.v. infusion every 2 weeks as second-line monotherapy of advanced colorectal cancer. Two doses were studied (250 and 200 mg/m) according to the risk of developing toxicity. Two groups of patients were studied: high-risk group (HR, 200 mg/m, n = 45; Karnofsky score 60-80% and/or the record of prior pelvic irradiation) and low-risk-group (LR, 250 mg/m, n = 51; Karnofsky score >80% and without prior pelvic irradiation). The mean number of cycles per patient was 7: 6.6 (HR group) and 8.3 (LR group). Median RDI was 0.96. The overall response rate was 8.9% [95% confidence interval (CI) 2.5-21.2%; HR group] and 15.7% (95% CI 7.0-28.5%; LR group), respectively. The LR group showed two complete responses and a higher percentage of stable disease (56.9 versus 33.3% in HR group). The median survival was 7.1 months (95% CI 5.2-8.9 months, HR group) and 11.7 months (95% CI 8.4-15.1 months, LR group). The median time to disease progression was 3.2 months (95% CI 1.0-5.4 months, HR group) and 5.3 months (95% CI 3.8-6.7 months, LR group). Both CPT-11 treatments were well tolerated. Grade 3/4 toxicity incidence was low, e.g. granulocytopenia (7% of patients in HR group and 9% in LR group) and delayed diarrhea (18% of patients in HR group and 14% in LR group). We conclude that the treatment of patients with the adjusted dose of CPT-11 according to prognostic factors for toxicity resulted in the improved toxicity profile, but showed poorer efficacy outcome. Therefore, the dose reduction in patients with low performance and treated with radiotherapy needs further investigation to provide some new insights on the benefit:risk ratio of such treatment.

Topoisomerase I Inhibitors in the Treatment of Gastrointestinal Cancer: From Intravenous to Oral Administration

This article reviews the current status of the topoisomerase I (top I) inhibitors in the treatment of gastrointestinal (GI) malignancies. We focus on oral drug administration, the mode of administration that is generally preferred by patients with cancer. However, the great majority of the studies have been performed with intravenous (I.V.) administration. The most extensively investigated GI malignancy in phase I/II studies is colorectal cancer (CRC), for which I.V. irinotecan is currently approved in the United States and Europe. We discuss the activity and efficacy of irinotecan as a single agent in CRC and in combination regimens. Also, results obtained with monotherapy and in combination treatment in other GI malignancies such as esophageal, gastric, and pancreatic cancer are discussed. Few phase I studies have been performed with oral irinotecan and its clinical activity has not yet been fully determined. Several top I inhibitors are discussed, including topotecan, 9-aminocamptothecin, rubitecan, exatecan, and lurtotecan. None of these agents, given orally or intravenously, have shown activity in CRC similar to that of I.V. irinotecan. However, several agents show promising results in other GI malignancies, eg, rubitecan and exatecan in pancreatic cancer. A complicating factor in the oral administration of the top I inhibitors is the often encountered low and variable oral bioavailability. This can partly be explained by the high affinity for the drug efflux pumps BCRP (ABCG2) and P-glycoprotein, which are highly expressed in the epithelial apical membrane of the GI tract. A novel approach to improve the oral bioavailability of the top I inhibitors by temporary blockade of the drug transporter BCRP is described.

Phase II study of irinotecan, 5-fluorouracil, and leucovorin in relapsed or metastatic colorectal cancer as first-line therapy

BACKGROUND

The purpose of this study was to assess the efficacy and toxicity of biweekly irinotecan plus 5-fluorouracil (FU) and leucovorin (LV) in patients with relapsed or metastatic colorectal cancer.

MATERIALS AND METHODS

Between March 2002 and May 2004, 24 patients with histologically confirmed relapsed or metastatic colorectal cancer were enrolled in this study. One chemotherapy cycle consisted of irinotecan 180 mg/m(2) on days 1 and 15; 5-FU 400 mg/m(2) bolus IV with 600 mg/m(2) by a 22 hour intravenous infusion on days 1, 2, 15 and 16; and leucovorin 20 mg/m(2) on days 1, 2, 15 and 16, every 4 weeks.

RESULTS

The median age of the 24 was 57.5 years (range, 38 approximately 69). Their metastatic sites included: the liver (62.5%), lung (20.8%), peritoneum (16.7%), lymph node (12.5%), ovary (8.3%) and pelvis/vagina (8.3%). Twenty-two patients were evaluable for a response. Six and 7 patients achieved partial responses and stable diseases, respectively. The overall response rate was 27.3% (95% Confidence interval; 10.3 approximately 44.5%). The median follow-up duration for surviving patients was 14.7 months (range, 1.7 approximately 26.5). Median overall survival (OS) and 1-year OS rates were 19 months and 86.3%, respectively. Median response duration and median progression free survival were 7.47 and 5.57 months, respectively. A total of 83 cycles (median 4 cycles) were administered. The main non-hematologic toxicities were nausea/vomiting (44.5%/18.1%) and diarrhea (8.4%). The most common hematologic toxicity was NCI grade I/II anemia (31.3%) and grade I/II neutropenia was 10.8%. There was no life-threatening toxicity.

CONCLUSION

The results suggested that irinotecan, 5-FU and leucovorin combination chemotherapy in a biweekly schedule is a practical and tolerable treatment option in patients with advanced colorectal cancer.

ZD9331 as Second- or Third-Line Therapy in Patients With Advanced Colorectal Cancer

This study investigated the efficacy and tolerability of ZD9331 as second- or third-line treatment for patients with advanced colorectal cancer (aCRC). One hundred patients were recruited to the study: 45 in group 1 (failed first-line 5-FU-based regimen) and 55 in group 2 (failed first-line 5-FU-based regimen and second-line irinotecan). Patients received ZD9331 as a 30-minute intravenous infusion on days 1 and 8 of a 3-week cycle, and treatment continued until disease progression (PD) or withdrawal. After a median of 4 cycles of treatment, there were no objective responses in group 1 (N = 37), 25 (67.6%) patients had a best overall response of stable disease (SD), and 12 (32.4%) had PD. After a median of 3 cycles of treatment, there were 2 (4.5%) partial responses in group 2 (N = 44), 21 (47.7%) patients had a best overall response of SD, 20 (45.4%) had PD, and 1 (2.3%) had clinical progression. At data cut-off, 59.5% and 77.3% of patients in groups 1 and 2, respectively, had PD. The main adverse events were neutropenia (69%), fatigue (53%), nausea (46%), and diarrhea (40%), and most (72.3%) were grade I/II. ZD9331 demonstrated minimal antitumor activity, and manageable toxicity, in the second- or third-line treatment of aCRC.

Immunohistochemical study of DNA topoisomerase I, DNA topoisomerase II alpha, p53, and Ki-67 in oral preneoplastic lesions and oral squamous cell carcinomas

Human DNA topoisomerase I (topo I) is the molecular target of the camptothecin group of anticancer drugs. Laboratory studies have shown that the cellular response to topo I-targeted drugs depends on the topo I expression and DNA replication rate and the apoptotic pathway activity. In this study, we tested potential indicators of the sensitivity of topo I-targeted drugs in 36 cases of oral squamous cell carcinoma (OSCC). Formalin-fixed, paraffin-embedded tissue sections were immunostained with monoclonal antibodies against Ki-67, p53, and topo I, and with polyclonal antibodies against DNA topoisomerase II-alpha (topo II-alpha). These markers were also tested in 18 epithelial hyperplastic lesions and 18 mild dysplasias. Immunostaining was quantified by the percentage of stained nuclei in each sample (the labeling index); 200 immunoreactive epithelial nuclei were counted per case for each antibody. The results support the possibility of using topo II-alpha staining for assessing the proliferative activity. High expression of topo II-alpha and topo I in OSCCs suggests that they may serve as potential indicators of sensitivity to topo I inhibitors. However, the apoptotic pathway assessed by p53 immunostaining was found to be uninformative. Analysis of the relationship between immunohistochemical results and clinical and pathologic parameters (the T and N stages and differentiation) showed that only the differentiation parameter correlated with the topo I expression rate. Thus, significant increase in the topo I expression in the poorly differentiated OSCCs suggests their higher sensitivity to drug treatment.

Phase I/II study of first-line irinotecan combined with 5-fluorouracil and folinic acid Mayo Clinic schedule in patients with advanced colorectal cancer

BACKGROUND

This multicentre phase I/II study was designed to determine the maximum tolerated dose of irinotecan when combined with 5-fluorouracil and folinic acid according to the Mayo Clinic schedule and to evaluate the activity of this combination as first-line therapy in patients with advanced colorectal cancer.

METHODS

Sixty-three patients received irinotecan (250 or 300 mg/m2, 30- to 90-minute intravenous infusion on day 1), immediately followed by folinic acid (20 mg/m2/day) and 5-fluorouracil (425 mg/m2, 15-minute bolus infusion) days 1 to 5, every four weeks.

RESULTS

Diarrhoea was dose limiting at 300 mg/m2 irinotecan in combination with 5-fluorouracil and folinic acid, and this was determined to be the maximum tolerated dose. Grade 3-4 neutropenia was the most frequently reported toxicity. The recommended dose of irinotecan for the phase II part of the study was 250 mg/m2. The response rate for the evaluable patient population was 36% (13/36), and 44% (16 patients) had stable disease (including 19% of minor response). For the intention-to-treat population, the response rate was 29% (14/49) and 35% (17 patients) stable disease (including 14% of minor response). The median time to progression was 7.0 months and the median survival was 12.0 months. Grade 3-4 non-haematological drug-related toxicities included delayed diarrhoea, stomatitis, fatigue, and nausea/vomiting. There were three deaths due to septic shock that were possibly or probably treatment-related.

CONCLUSIONS

This regimen of irinotecan in combination with the Mayo Clinic schedule of bolus 5-fluorouracil/folinic acid every four weeks showed activity as first-line therapy in patients with advanced colorectal cancer. In keeping with other published results of studies using bolus 5-fluorouracil combined with irinotecan, the use of this regimen is limited by a relatively high rate of grade 3-4 neutropenia, and the combination of irinotecan and infusional 5-fluorouracil / folinic acid should remain the regimen of first choice.

Dose-finding study of weekly 24-h continuous infusion of 5-fluorouracil associated with alternating oxaliplatin or irinotecan in advanced colorectal cancer patients

PURPOSE

To determine maximum tolerated dose, safety and efficacy of weekly 24 h infusional 5-fluorouracil (5-FU) combined alternately with oxaliplatin and irinotecan.

PATIENTS AND METHODS

Advanced colorectal carcinoma patients in first- or second-line chemotherapy received increasing doses of 5-FU (weekly 24 h continuous intravenous infusion without leucovorin) on days 1, 8, 15 and 22, irinotecan days 1 and 15; and oxaliplatin days 8 and 22, every 35 days.

RESULTS

Thirty-four patients received 175 cycles. The median age was 64 years (range 47-78). Eighteen per cent of patients had the primary tumor in the rectum, with a median of one disease site (range one to three), and liver involvement in 88% and lung in 38%. Six (18%) patients had chemotherapy for prior advanced disease. The most frequent grade 3-4 toxicity was neutropenia (41% of patients), but the regimen was well tolerated clinically, with febrile neutropenia in two patients and grade 4 neutropenia lasting >7 days in one; grade 3-4 diarrhea, nausea and vomiting in 6% of patients; grade 3-4 peripheral neuropathy in 9% of patients. Seventeen patients had a partial response (50%; 95% confidence interval 33%-67%), 13 had stable disease and one had progressive disease. Five patients underwent metastatic surgical resection after tumor shrinkage. Median response duration was 14 months (range 4.7-29.2+) and median time to progression was 11.3 months (range 1.1+-30.7+).

CONCLUSIONS

This combination three-drug regimen is feasible and well tolerated without toxicity overlap. Preliminary antitumor activity compares well with standard double combinations, with an unusually long median time to progression. The recommended dose is 5-FU 3000 mg/m(2), weekly for 4 weeks, irinotecan 100 mg/m(2) days 1 and 15, oxaliplatin 80 mg/m(2) days 8 and 22. Further assessment of antitumor activity and safety is warranted.

New systemic frontline treatment for metastatic colorectal carcinoma

Options for first-line chemotherapy in patients with metastatic colorectal carcinoma have broadened considerably with the introduction of irinotecan and oxaliplatin. Furthermore, the oral fluoropyrimidine capecitabine has demonstrated efficacy in Phase III trials and recently was approved for first-line treatment in Europe and the United States. Capecitabine yielded similar median times to disease progression and median survival rates compared with bolus 5-fluorouracil (5-FU)/leucovorin (LV) (Mayo Clinic/North Central Cancer Treatment Group regimen), with superior and similar response rates, respectively. However, its role as a first-line, single-agent substitute for intermittent infusional 5-FU/LV remains to be defined. The addition of irinotecan or oxaliplatin to 5-FU/LV resulted in improved response rates and progression-free survival in large, randomized trials; moreover, irinotecan-containing regimens resulted in improved overall survival. Prevalent regimens of irinotecan/5-FU/LV and oxaliplatin/5-FU/LV have been compared in two randomized Phase III trials. One study demonstrated the statistical superiority of oxaliplatin/infusional 5-FU/LV over irinotecan/bolus 5-FU/LV in terms of response, time to disease progression, and median survival; however, those advantages may have been attributable to infusional administration or to major differences in second-line therapy. A randomized Phase III study comparing irinotecan and oxaliplatin in combination with the same infusional 5-FU/LV regimens and crossover in case of disease progression showed equivalent efficacy for both schedules in the first-line setting, but the irinotecan combination proved beneficial in terms of safety. New molecular targeted agents, such as angiogenesis-modulating compounds (e.g., bevacizumab) and epidermal growth factor receptor inhibitors (e.g., cetuximab), are under clinical investigation. This review updates current systemic frontline treatments and future perspectives for patients with advanced colorectal carcinoma.

Phase I/II trial of irinotecan plus high-dose 5-fluorouracil (TTD regimen) as first-line chemotherapy in advanced colorectal cancer

BACKGROUND

We conducted a phase I/II study of weekly irinotecan [30 min intravenous (i.v.) infusion] combined with 5-fluorouracil (5-FU 3 g/m(2) weekly 48 h i.v. infusion, TTD regimen) as first-line chemotherapy for patients with advanced colorectal cancer (CRC).

PATIENTS AND METHODS

The maximum tolerated dose (MTD) and the dose-limiting toxicity (DLT) in the treatment of gastrointestinal solid tumors (in phase I), and the antitumor activity and toxicity of the recommended phase I dose (in phase II) were determined.

RESULTS

Diarrhea was the DLT, and irinotecan 80 mg/m(2) plus 5-FU 3 g/m(2) was the recommended phase I dose. In phase II, the confirmed response rate was 44% [95% confidence interval (CI) 29% to 59%] and the median overall survival was 23.8 months. However, grade 3/4 diarrhea affected 59% of patients and led to withdrawal of three patients. A second cohort of patients studied using the same schedule but with a reduced 5-FU starting dose of 2.25 g/m(2) showed improved tolerance (the incidence of grade 4 diarrhea decreased from 28% to 11% and overall grade 3/4 diarrhea to 56%, with no patient withdrawals) but the confirmed response rate was 28% (95% CI 14% to 45%) and median overall survival was 17.2 months.

CONCLUSIONS

We found weekly irinotecan 80 mg/m(2) plus TTD regimen (5-FU 2.25 g/m(2) given as 48-h i.v. infusion) to be a feasible and active combined chemotherapy for the first-line treatment of advanced colorectal cancer.

Continuous infusion of hepatic arterial irinotecan in pretreated patients with colorectal cancer metastatic to the liver

BACKGROUND

Irinotecan is an active drug in colorectal cancer. In patients with liver metastases, hepatic arterial infusion of irinotecan could theoretically result in higher exposure to the drug. In order to determine the efficacy of hepatic arterial irinotecan we conducted a phase II study in pretreated patients with liver metastases of colorectal cancer.

PATIENTS AND METHODS

Patients with measurable liver metastases of colorectal cancer with World Health Organization performance status (WHO PS) <2 were treated with a 5-day continuous infusion of hepatic arterial irinotecan every 3 weeks at a dose of 20 mg/m(2)/day.

RESULTS

Of the 25 patients included, 22 were evaluable for response. Three of 22 patients (13.6%) had a partial response, nine (40.9%) had stable disease and 10 (45.4%) had progressive disease. No complete responses were observed. Median time to progression was 2.8 (range 1.2-23.8) months. Major toxicities were vomiting and diarrhea. There was no major hematological toxicity.

CONCLUSIONS

Five-day continuous hepatic arterial infusion of irinotecan 20 mg/m(2)/day has low activity in patients with liver metastases of colorectal cancer previously treated by chemotherapy.

Randomized multicenter Phase II trial of two different schedules of irinotecan combined with capecitabine as first-line treatment in metastatic colorectal carcinoma

BACKGROUND

The aim of the current randomized Phase II study was to investigate the efficacy and safety of capecitabine combined with irinotecan as first-line treatment in metastatic colorectal carcinoma (CRC).

METHODS

A total of 140 patients received capecitabine at a dose of 1250 mg/m(2) twice daily on Days 2-15 and irinotecan at a dose of either 300 mg/m(2) on Day 1 (Arm A) or 150 mg/m(2) on Days 1 and 8 (Arm B) every 3 weeks. During the course of the study, enrollment was continued using lower doses of capecitabine (1000 mg/m(2) twice daily) and irinotecan (Arm A: 240 mg/m(2); Arm B: 120 mg/m(2)) to improve the safety profile of the combinations.

RESULTS

Efficacy was evaluable in 134 patients (68 in Arm A, 66 in Arm B). Objective responses were observed in 46% of the patients (8% complete response [CR]), including 47% in Arm A (9% CR; 38% partial response [PR]) and 44% in Arm B (8% CR; 36% PR). The median progression-free survival was 8.3 months in Arm A and 7.6 months in Arm B. Among the first 52 patients treated with the higher doses, the most frequent Grade 3-4 adverse event was diarrhea (27%). The lower doses adopted in the subsequent 88 patients led to better diarrhea control, particularly in Arm A, and significant reductions in the incidence of all-grade hand-foot syndrome and abdominal pain.

CONCLUSIONS

The capecitabine and irinotecan combination was a highly active first-line therapy in metastatic CRC. An acceptable safety profile was observed after dose reduction, particularly when irinotecan was administered on 1 day.

Management of Colorectal Cancer in Elderly Patients

The treatment of colorectal cancer has evolved dramatically over the last 15 years. Advances in surgery, radiotherapy and chemotherapy have enabled oncologists to cure more patients and offer improved quality of life to patients not amenable to cure. Specific knowledge of colorectal cancer care of the elderly, while lagging behind the treatment of younger patients, is beginning to emerge. Informed by recent trials, the approach towards elderly patients is shifting towards more aggressive treatment and multimodal therapy. Surgeons are operating on the elderly with greater frequency, less operative mortality and greater success; 5-year survival following potentially curative surgery has risen from 50% to 67%.Research of adjunctive therapy for colorectal cancer is enrolling more elderly patients, and with this has come an understanding of the role of chemotherapeutic agents in the treatment of the elderly, used individually and within multi-drug regimens. This research offers insight into how the elderly respond to chemotherapy, informing clinicians on anticipated benefits and toxicities of treatment. Fluorouracil-based regimens, which have long been the standard adjuvant chemotherapy, have been shown to offer benefits to the elderly compared with those not receiving adjuvant chemotherapy (71% versus 64% 5-year survival), and to cause similar toxicities as seen in younger patients. The role of novel chemotherapeutic agents in the treatment of elderly patients with colorectal cancer is also emerging, with studies finding that irinotecan, in combination with a fluorouracil-based regimen, can offer a further survival benefit of over 2 months compared with fluorouracil alone. While newer agents such as capecitabine, oxaliplatin, raltitrexed and tegafur/uracil (UFT) have been focused upon by clinical researchers, data on their use in the elderly remain unconvincing. Not only are we approaching a clearer understanding of the effectiveness of cancer care among the elderly, but research is also beginning to identify the cost effectiveness of both standard and emerging chemotherapeutic agents. Cost effectiveness of fluorouracil-based regimens, depending on delivery strategy, use of modulating agents and stage of cancer vary from US dollars 2000 per quality-adjusted life-year (QALY) to US dollars 20200 per QALY (1992 values). Irinotecan therapy has not been fully investigated from the perspective of cost effectiveness; the figure of US dollars 10000 per QALY (1998 values) for irinotecan monotherapy over fluorouracil regimens is likely an underestimate, while cost analysis of irinotecan and fluorouracil combination therapy has not yet been reported. Our understanding of cost effectiveness of other novel agents has lagged behind; further research on these agents is needed. Nonetheless, as the effects of these novel agents upon both outcomes and costs continue to be defined, both curative and palliative treatment of colorectal cancer in the elderly patient will become more sophisticated and effective.

Prevention of chemotherapy and radiation toxicity with glutamine

GOALS OF THE WORK

Malignancy produces a state of physiologic stress that is characterized by a relative deficiency of glutamine, a condition that is further exacerbated by the effects of cancer treatment. Glutamine deficiency may impact on normal tissue tolerance to antitumor treatment, and may lead to dose reductions and compromised treatment outcome. Providing supplemental glutamine during cancer treatment has the potential to abrogate treatment-related toxicity. We reviewed the available data on the use of glutamine to decrease the incidence and severity of adverse effects due to chemotherapy and/or radiation in cancer patients.

METHODS

We performed a search of the MEDLINE database during the time period 1980-2003, and reviewed the English language literature of both human and animal studies pertaining to the use of glutamine in subjects with cancer. We also manually searched the bibliographies of published articles for relevant references.

MAIN RESULTS

The available evidence suggests that glutamine supplementation may decrease the incidence and/or severity of chemotherapy-associated mucositis, irinotecan-associated diarrhea, paclitaxel-induced neuropathy, hepatic veno-occlusive disease in the setting of high dose chemotherapy and stem cell transplantation, and the cardiotoxicity that accompanies anthracycline use. Oral glutamine supplementation may enhance the therapeutic index by protecting normal tissues from, and sensitizing tumor cells to chemotherapy and radiation-related injury.

CONCLUSIONS

The role of glutamine in the prevention of chemotherapy and radiation-induced toxicity is evolving. Glutamine supplementation is inexpensive and it may reduce the incidence of gastrointestinal, neurologic, and possibly cardiac complications of cancer therapy. Further studies, particularly placebo-controlled phase III trials, are needed to define its role in chemotherapy-induced toxicity.

Phase I and pharmacokinetic study of two different schedules of oxaliplatin, irinotecan, Fluorouracil, and leucovorin in patients with solid tumors

PURPOSE

We sought to determine the maximum-tolerated dose (MTD) and evaluate the toxicities and clinical activity of two irinotecan (CPT-11), fluorouracil (FU), leucovorin (LV), and oxaliplatin schedules in patients with advanced solid tumors. Additionally, we investigated the effect of CPT-11 on oxaliplatin pharmacokinetics.

PATIENTS AND METHODS

Thirteen patients (cohort 1) received intravenous CPT-11 (infusion) and FU/LV (bolus) on days 1, 8, 15, and 22 and oxaliplatin (infusion) on days 1 and 15 every 6 weeks for a total 37 courses (median, three courses) at three dose levels. Twenty-two cohort 2 patients received intravenous CPT-11/oxaliplatin (infusion, day 1) and FU/LV (90-minute bolus infusion, days 2 to 5) every 3 weeks for a total of 122 courses (median, four courses) at three dose levels. Pharmacokinetic and neurotoxicity assessments were performed at the cohort 2 MTD.

RESULTS

Dose-limiting toxicity (DLT) seen in both cohorts at the starting dose required dose de-escalation. Cohort 1 DLT included diarrhea and neutropenia. In cohort 2, diarrhea, vomiting, dehydration, neutropenia, febrile neutropenia, and paresthesias were DLTs. Antitumor activity was seen in both cohorts. In cohort 2, the total platinum area under the curve of patients increased 17% in cycle 2 (P =.048), but objective neurotoxicity was not seen.

CONCLUSION

The toxicities resulting from the addition of oxaliplatin to CPT-11/FU/LV are significant but manageable. The MTDs for the weekly schedule are CPT-11 (75 mg/m2), oxaliplatin (50 mg/m2), FU (320 mg/m2), and LV (20 mg/m2); and, for the 3-weekly schedule, the MTDs are CPT-11 (175 mg/m2), oxaliplatin (85 mg/m2), FU (240 mg/m2), and LV (20 mg/m2). Second-cycle platinum accumulation raises the possibility for enhanced cumulative neurotoxicity with CPT-11/oxaliplatin combinations.

Capecitabine and irinotecan as first-line chemotherapy in patients with metastatic colorectal cancer: results of an extended phase I study

BACKGROUND

To define the maximum-tolerated dose (MTD) and to evaluate the dose-limiting toxicities (DLTs) of the combination of capecitabine and irinotecan in patients with metastatic colorectal cancer.

PATIENTS AND METHODS

Thirty-seven patients with measurable metastatic colorectal cancer with no prior chemotherapy for metastatic disease were treated at three dose levels (DLs). For the first two dose levels, irinotecan (70 mg/m(2)) was administered once a week for 6 weeks in combination with 2 weeks of capecitabine at 1000 mg/m(2) (DL1) or 1250 mg/m(2) (DL2) twice daily, starting on days 1 and 22. In the last dose escalation step, the dose of irinotecan was increased to 80 mg/m(2) (DL3). One cycle lasted 7 weeks.

RESULTS

In the subsequent phase I trial, 96 cycles of capecitabine and irinotecan were administered. At DL3, three out of six patients experienced DLTs (diarrhea, neutropenia, asthenia). In order to confirm the safety of the recommended dose, DL2 was extended to 15 patients. Five patients (33%) showed DLTs at this dose level, which was considered too high to embark on further clinical studies. Subsequently, the starting dose (DL1) was extended to a total of 16 patients, with diarrhea being the main toxicity. The overall response rate was 38% [95% confidence interval (CI) 21% to 58%], with a median response duration of 8.7 months (95% CI 6.4-11.5 months).

CONCLUSIONS

The recommended doses for further studies are irinotecan 70 mg/m(2) and capecitabine 1000 mg/m(2). The combination of capecitabine and irinotecan appears to have significant therapeutic efficacy with manageable toxicity.

A randomized phase II trial of irinotecan in combination with infusional or two different bolus 5-fluorouracil and folinic acid regimens as first-line therapy for advanced colorectal cancer

BACKGROUND

Three different therapeutic regimens of irinotecan (CPT-11) in combination with 5-fluorouracil (5-FU) and folinic acid (FA) were evaluated for efficacy and safety in the first-line therapy of advanced colorectal cancer.

PATIENTS AND METHODS

Patients were randomly assigned to receive intravenously either: CPT-11 125 mg/m(2), FA 20 mg/m(2) followed by 5-FU 500 mg/m(2) bolus, weekly for 4 weeks (arm A, Saltz regimen); or CPT-11 180 mg/m(2) day 1 then FA 200 mg/m(2) over 2 h and 5-FU 400 mg/m(2) bolus and 5-FU 600 mg/m(2) 22-h infusion on days 1 and 2, every 2 weeks (arm B, Douillard regimen); or CPT-11 350 mg/m(2) (days 1 and 43) alternating with FA 20 mg/m(2)/day followed by 5-FU bolus 425 mg/m(2)/day during 5 days (days 22-26) (arm C, Mayo Clinic regimen).

RESULTS

A total of 154 patients were included in the study (arm A, 51 patients; arm B, 53; arm C, 50). Overall response rates for the intention-to-treat populations were 33% [95% confidence interval (CI) 21% to 48%], 42% (95% CI 28% to 56%) and 30% (95% CI 18% to 45%) for arms A, B and C, respectively. Median times to progression were 6, 8 and 7 months for arms A, B and C, respectively. Median survival times were 15, 12 and 17 months for arms A, B and C, respectively. Overall response rates for the evaluable patient populations were 40% (95% CI 24% to 58%) in arm A, 44% (95% CI 29% to 60%) in arm B and 31% (95% CI 17% to 47%) in arm C. Neutropenia was the main serious adverse event in arms A (30% of patients) and C (22% of patients) but occurred in only 8% of patients in arm B. Delayed diarrhea was the main severe adverse event for the three regimens, from 15% to 22%.

CONCLUSION

All three regimens were highly active. The biweekly combination of CPT-11 and 5-FU/FA (arm B) was notable for its low incidence of grade 3/4 neutropenia. The incidence of grade 3/4 delayed diarrhea was equivalent for the three treatment arms.

Phase II study of irinotecan and mitomycin C in 5-fluorouracil-pretreated patients with advanced colorectal and gastric cancer

The aim of this phase II study was to investigate the tolerance and efficacy of a second-line irinotecan/mitomycin C combination in patients with advanced gastric or colorectal cancer, pretreated with 5-fluorouracil. Forty patients who had received 5-fluorouracil-based chemotherapy for advanced disease or adjuvant 5-fluorouracil treatment were enrolled. Chemotherapy consisted of irinotecan 125 mg/m2 and mitomycin C 5 mg/m2, given every 2 weeks. Treatment was continued until progression or limiting toxicity occurred. Five partial responses (12.5%), 22 cases of stable disease (55%) and 13 of progression (32.5%) were registered, giving an overall response rate of 12.5% [95% confidence interval (CI), 4.2-26.8%] and an overall control of tumor growth in 67.5% (95% CI, 50.8-81.4%) of patients. Median progression-free survival was 5 months, median survival time 8 months, and 1-year probability of survival was 21.6%. Diarrhea and neutropenia affected 25% and 12.5% of patients respectively, with only 7.5% experiencing grade 3-4 toxicity. There were no chemotherapy-related deaths or hospitalizations. This combination regimen was shown to be moderately effective with substantially lower toxicity than irinotecan monotherapy in 5-fluorouracil-pretreated patients with advanced gastric or colorectal cancer. It may represent an attractive option in patients at high risk for developing specific irinotecan toxicity.

Bimonthly leucovorin, infusion 5-fluorouracil, hydroxyurea, and irinotecan (FOLFIRI-2) for pretreated metastatic colorectal cancer

Irinotecan has shown activity in advanced colorectal cancer resistant to leucovorin and fluorouracil. Preclinical experiments on cell cultures and human tumor xenografts indicated potential synergy when combining irinotecan and fluorouracil. We designed a new regimen combining leucovorin, fluorouracil, irinotecan, and hydroxyurea (FOLFIRI-2) and conducted a phase II study to establish its efficacy and tolerance in advanced colorectal cancer refractory to fluorouracil and oxaliplatin. Treatment was repeated every 2 weeks and consisted of leucovorin 400 mg/m2 on day 1, immediately followed by 46 hours of continuous infusion of fluorouracil 2,000 mg/m2, irinotecan 180 mg/m2 on day 3, and hydroxyurea 1,500 mg the day before leucovorin, and on days 1 and 2. Treatment was continued until progression or limiting toxicity. Twenty-nine heavily pretreated patients entered the study. Five patients achieved an objective response (17%), and 12 obtained stabilization of disease or minor response (52%). Five patients failed to continue treatment (17%) because of toxicity or worsening condition. From the start of FOLFIRI-2 treatment, median progression-free survival was 4.1 months and median survival was 9.7 months. Grade III/IV National Cancer Institute-Common Toxicity Criteria toxicities were nausea 17%, diarrhea 31%, mucositis 14%, neutropenia 52%, and febrile neutropenia 14%. FOLFIRI-2 achieved a good rate of response and stabilization in heavily pretreated patients despite significant toxicity.