Cetuximab plus irinotecan in pretreated metastatic colorectal cancer patients: the ELSIE study.

AIM: To evaluate the efficacy and safety of cetuximab plus irinotecan in irinotecan-refractory metastatic colorectal cancer (mCRC) patients from South-East Asia and Australia. METHODS: In this open-label, phase II study, the main eligibility criteria were epidermal growth factor receptor-positive mCRC with progressive disease within 3 mo of an irinotecan-based regimen as the most recent chemotherapy. Patients received cetuximab 400 mg/m2 initially, then 250 mg/m2 every week, with the same regimen of irinotecan on which the patients had progressed (4 pre-defined regimens allowed). The primary objective was evaluation of progression-free survival (PFS) at 12 wk. Secondary objectives included a further investigation of PFS, and an assessment of the overall response rate (ORR), duration of response, time to treatment failure (TTF), overall survival and the safety profile. RESULTS: One hundred and twenty nine patients were enrolled from 25 centers in the Asia-Pacific region and of these 123 received cetuximab plus irinotecan. The most common recent irinotecan regimen used was 180 mg/m2 every 2 wk which had been used in 93 patients (75.6%). The PFS rate at 12 wk was 50% (95% confidence interval (CI, 41-59) and median PFS time was 12.1 wk (95% CI: 9.7-17.7). The ORR was 13.8% (95% CI: 8.3-21.2) and disease control rate was 49.6% (95% CI: 40.5-58.8). Median duration of response was 31.1 wk (95% CI: 18.0-42.6) and median overall survival was 9.5 mo (95% CI, 7.5-11.7). The median TTF was 11.7 wk (95% CI: 9.1-17.4). Treatment was generally well tolerated. The most common grade 3/4 adverse events were diarrhea (13.8%), neutropenia (8.9%), rash (5.7%) and vomiting (5.7%). CONCLUSION: In patients from Asia and Australia, this study confirms the activity and safety of cetuximab plus irinotecan observed in previous studies in Europe and South America.

Pharmacokinetic profile of cetuximab (Erbitux) alone and in combination with irinotecan in patients with advanced EGFR-positive adenocarcinoma.

This trial assessed pharmacokinetic interactions between cetuximab and irinotecan. Patients were placed in either in group A (irinotecan 350 mg/m2/3 weeks and 400 mg/m2 cetuximab at week 2 then 250 mg/m2/week) or group B (cetuximab weekly starting week 1 then irinotecan starting week 4). Patient plasma or serum samples from each treatment arm were analysed using HPLC and ELISA. Among 14 patients, compartmental model showed no significant differences in mean plasma AUC at week 1 versus week 4 for irinotecan (44,388 versus 39,800 microg/ml/h) and cetuximab (20,441 versus 23,363 microg/ml/h), respectively. Half-lifes (standard deviations) for irinotecan were 16.02 (+/-8.41) h at week 1 and 13.99 (+/-2.14) h at week 4, and for cetuximab 106 (+/-32) at week 3 and 111 (+/-30) h at week 4. Mean concentration-versus-time profiles either alone or in combination were superimposable for cetuximab and irinotecan. From this study, we conclude that there is no evidence of pharmacokinetic interaction between irinotecan and cetuximab.

Multicenter, phase II study of cetuximab in combination with carboplatin in patients with recurrent or metastatic nasopharyngeal carcinoma.

PURPOSE: To evaluate efficacy and toxicity of cetuximab plus carboplatin in recurrent or metastatic nasopharyngeal carcinoma (NPC) resistant to platinum treatment. PATIENTS AND METHODS: A multicenter, open-label, single-arm, phase II study in patients with epidermal growth factor receptor-expressing NPC who progressed on or within 12 months after termination of platinum-based chemotherapy for recurrent or metastatic disease. Cetuximab was administered at an initial dose of 400 mg/m2 followed by weekly doses of 250 mg/m2. Carboplatin area under the curve 5 was administered every 3 weeks up to a maximum of eight cycles. RESULTS: Sixty patients were enrolled (46 males, 14 females; median age, 44.5 years; range, 23 to 64 years), and all patients were included in the intent-to-treat and safety analyses. Of the 59 patients assessable for efficacy, there were seven partial responses (11.7%), 29 patients (48.3%) with stable disease, and 23 patients (38.3%) with progressive disease, giving an overall response rate of 11.7% (95% CI, 4.8% to 22.6%). The median time to progression was 81 days in all patients and was longest in the group of patients with a confirmed response (173 days). The median overall survival time was 233 days in all patients. Six patients (10%) experienced serious treatment-related adverse events. Grade 3 or 4 toxicities occurred in 31 patients (51.7%); of these patients, only 19 (31.7%) were considered to have toxicity related to cetuximab. CONCLUSION: Cetuximab in combination with carboplatin demonstrates clinical activity and an acceptable safety profile in heavily pretreated patients with recurrent or metastatic NPC who had previously experienced treatment failure with platinum-based therapy.

Cetuximab monotherapy and cetuximab plus irinotecan in irinotecan-refractory metastatic colorectal cancer.

BACKGROUND: The epidermal growth factor receptor (EGFR), which participates in signaling pathways that are deregulated in cancer cells, commonly appears on colorectal-cancer cells. Cetuximab is a monoclonal antibody that specifically blocks the EGFR. We compared the efficacy of cetuximab in combination with irinotecan with that of cetuximab alone in metastatic colorectal cancer that was refractory to treatment with irinotecan. METHODS: We randomly assigned 329 patients whose disease had progressed during or within three months after treatment with an irinotecan-based regimen to receive either cetuximab and irinotecan (at the same dose and schedule as in a prestudy regimen [218 patients]) or cetuximab monotherapy (111 patients). In cases of disease progression, the addition of irinotecan to cetuximab monotherapy was permitted. The patients were evaluated radiologically for tumor response and were also evaluated for the time to tumor progression, survival, and side effects of treatment. RESULTS: The rate of response in the combination-therapy group was significantly higher than that in the monotherapy group (22.9 percent [95 percent confidence interval, 17.5 to 29.1 percent] vs. 10.8 percent [95 percent confidence interval, 5.7 to 18.1 percent], P=0.007). The median time to progression was significantly greater in the combination-therapy group (4.1 vs. 1.5 months, P<0.001 by the log-rank test). The median survival time was 8.6 months in the combination-therapy group and 6.9 months in the monotherapy group (P=0.48). Toxic effects were more frequent in the combination-therapy group, but their severity and incidence were similar to those that would be expected with irinotecan alone. CONCLUSIONS: Cetuximab has clinically significant activity when given alone or in combination with irinotecan in patients with irinotecan-refractory colorectal cancer.