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

A phase I study of UGT1A1 *28/*6 genotype-directed dosing of irinotecan (CPT-11) in Korean patients with metastatic colorectal cancer receiving FOLFIRI

PURPOSE

A UGT1A1 genotype-directed dose escalation of irinotecan (CPT-11) was performed in patients with metastatic colorectal cancer receiving first-line FOLFIRI chemotherapy.

METHODS

Patients were genotyped for UGT1A1 and stratified according to the number of defective alleles (DA; *28 and *6). The irinotecan dose was escalated with a fixed dose of 5-fluorouracil and leucovorin in a standard 3 + 3 design.

RESULTS

In 43 enrolled patients, the maximum tolerated dose (MTD) was 300 mg/m² for the 1 DA group, while the MTD was not reached for the 0 DA group with 1 dose-limiting toxicity (DLT) at 330 mg/m² and for the 2 DA group with 0 DLT at 150 mg/m². Because of the risk of being exposed to unsafe doses, the trial was terminated before the MTD was reached in the 0 DA and 2 DA groups. The recommended doses were 300 (0 DA), 270 (1 DA) and 150 (0 DA) mg/m². The 2 DA group displayed 27% lower SN-38 exposure levels relative to the 0 and 1 DA groups (95% CI, 0.47-1.15).

CONCLUSIONS

The MTD of irinotecan differed according to the UGT1A1 genotype, and higher doses of irinotecan are feasible with sLV5FU2 compared to the present regulatory approved doses.

A phase II study of irinotecan, 5-fluorouracil and leucovorin for treatment in patients with previously untreated advanced colorectal cancer

PURPOSE

We prospectively conducted a non-randomized phase II trial to evaluate the efficacy and safety of combination irinotecan, leucovorin (LV) and 5-fluorouracil (FU) as a first-line regimen for treating patients with previously untreated advanced colorectal cancer (CRC).

MATERIALS AND METHODS

Twenty-six previously untreated patients with advanced, recurrent or metastatic CRC were enrolled in this study. The patients received either irinotecan 180 mg/m(2) on day 1 with LV bolus of 200 mg/m(2) and FU bolus of 400 mg/m(2), and this was followed by FU continuous infusion of 600 mg/m(2) on day 1 and day 2 (the FOLFIRI regimen), or they were treated with LV bolus of 400 mg/m(2) and FU bolus of 400 mg/m(2) followed by FU continuous infusion of 2,400 mg/m(2) for 46 hours (the simplified FOLFIRI regimen), and these treatments were repeated every 2 weeks until disease progression.

RESULTS

The objective response rate was 23.1% (6/26) respectively, for both treatments. The median time to progression was 5.3 months (range: 0.4 approximately 19.9), and the overall survival was 11.2 months (range: 0.5 approximately 52.3). The prognostic factor for longer survival was the Eastern Cooperative Oncology Group (ECOG) performance status (PS). The non-hematological toxicities were similar for both treatment groups, with more frequent grade >or=3 neutropenia being noted for the simplified FOLFIRI regimen.

CONCLUSION

The biweekly irinotecan based regimen was demonstrated to have a moderate antitumor activity with acceptable toxicity profiles, and the ECOG PS was the independent prognostic factor.

Irinotecan, continuous 5-fluorouracil, and low dose of leucovorin (modified FOLFIRI) as first line of therapy in recurrent or metastatic colorectal cancer

BACKGROUND

Irinotecan, in combination with 5-fluorouracil (5-FU) and a high dose of leucovorin (LV), known as FOLFIRI regimen, has shown activity in recurrent or metastatic colorectal cancer. Therefore, we evaluated the efficacy and safety of irinotecan, 5-FU and a low dose of LV (modified FOLFIRI) as a first line of therapy for patients with relapsed or metastatic colorectal cancer.

METHODS

Between January 2002 and October 2004, 44 patients with histologically confirmed recurrent or metastatic colorectal cancer were enrolled. The chemotherapy regimen schedule consisted of 180 mg/m2 of irinotecan being administered intravenously (i.v) on Day 1, 400 mg/m2 of 5-FU via i.v bolus with 600 mg/m2 of continuous infusion for 22 hrs on both Day 1 and 2, and 20 mg/m2 of leucovorin on both Day 1 and 2 , repeated every two weeks.

RESULTS

The overall response rate was 47.8%. Of the 40 evaluated patients, one had CR (2.3%) and 20 had PR (46.5%). Toxicities were mild and easily manageable. Three patients experienced 23 episodes of Grade 3/4 leukopenia., Only one patient developed Grade 3/4 diarrhea. None experienced Grade 3/4 thrombocytopenia.

CONCLUSION

Modified FOLFIRI with a low dose of LV is an effective and tolerable regimen for patients with recurrent or metastatic colorectal cancer.

Responsiveness of CPT-11 in respect to hMLH1 and hMSH2 protein expression in the primary colorectal cancer

PURPOSE

The aim of this study was to evaluate the responsiveness to CPT-11 with respect to hMLH1 and hMSH2 protein expressions in primary colorectal tumors.

MATERIALS AND METHODS

91 patients with colorectal cancer treated having undergone surgery and postoperative CPT-11-based adjuvant chemotherapy, between 1997 and 2002, were prospectively recruited. Tumor samples were immunohistochemically analyzed for the expressions of hMLH1, hMSH2, p53 and CEA proteins.

RESULTS

Of the 91 tumors, 6 (6.6%) and 4 (4.4%) showed loss of hMLH1 and hMSH2 protein expressions, respectively. The response rate of patients with tumors not expressing either hMLH1 or hMSH2 was higher than that of those expressing either of these proteins (p=0.026). Patients with tumors not expressing hMLH1 showed a significantly better response to CPT-11 (p=0.04). The responsiveness was not associated with the expressions of hMSH2, p53 or CEA. There were no correlations between drug toxicity and the expressions of hMLH1, hMSH2 or p53. The overall survival was better in patients responsive to CPT-11-based chemotherapy compared to non-responders.

CONCLUSION

The immunohistochemical determination of loss of hMLH1 and hMSH2 expressions may be used in determining the responsiveness to CPT-11-based chemotherapy. Our results suggest that hMLH1 protein expression may be a predictor for CPT-11 responsiveness in patients with colorectal cancer.