Fluorouracil, leucovorin, and oxaliplatin with and without cetuximab in the first-line treatment of metastatic colorectal cancer

PURPOSE

This randomized study assessed whether the best overall response rate (ORR) of cetuximab combined with oxaliplatin, leucovorin, and fluorouracil (FOLFOX-4) was superior to that of FOLFOX-4 alone as first-line treatment for metastatic colorectal cancer. The influence of KRAS mutation status was investigated.

PATIENTS AND METHODS

Patients received cetuximab (400 mg/m(2) initial dose followed by 250 mg/m(2)/wk thereafter) plus FOLFOX-4 (oxaliplatin 85 mg/m(2) on day 1, plus leucovorin 200 mg/m(2) and fluorouracil as a 400 mg/m(2) bolus followed by a 600 mg/m(2) infusion during 22 hours on days 1 and 2; n = 169) or FOLFOX-4 alone (n = 168). Treatment was continued until disease progression or unacceptable toxicity. KRAS mutation status was assessed in the subset of patients with assessable tumor samples (n = 233).

RESULTS

The confirmed ORR for cetuximab plus FOLFOX-4 was higher than with FOLFOX-4 alone (46% v 36%). A statistically significant increase in the odds for a response with the addition of cetuximab to FOLFOX-4 could not be established (odds ratio = 1.52; P = .064). In patients with KRAS wild-type tumors, the addition of cetuximab to FOLFOX-4 was associated with a clinically significant increased chance of response (ORR = 61% v 37%; odds ratio = 2.54; P = .011) and a lower risk of disease progression (hazard ratio = 0.57; P = .0163) compared with FOLFOX-4 alone. Cetuximab plus FOLFOX-4 was generally well tolerated.

CONCLUSION

KRAS mutational status was shown to be a highly predictive selection criterion in relation to the treatment decision regarding the addition of cetuximab to FOLFOX-4 for previously untreated patients with metastatic colorectal cancer.

Cetuximab plus irinotecan in heavily pretreated metastatic colorectal cancer progressing on irinotecan: MABEL Study

PURPOSE

This large, multinational study aimed to confirm in a community practice setting the efficacy and safety of cetuximab plus irinotecan in patients with epidermal growth factor-expressing metastatic colorectal cancer (mCRC) who had recently failed an irinotecan-containing regimen.

PATIENTS AND METHODS

The primary objective was to determine the progression-free survival (PFS) rate at 12 weeks. The initial cetuximab dose was 400 mg/m(2) and was followed weekly by 250 mg/m(2); irinotecan (according to prestudy regimen) was given weekly (125 mg/m(2) weekly for 4 of 6 weeks), every 2 weeks (180 mg/m(2) each), or every 3 weeks (350 mg/m(2) each).

RESULTS

The intention-to-treat/safety population comprised 1,147 treated patients who received irinotecan weekly (n = 93); every 2 weeks (n = 670); every 3 weeks (n = 356); or another dose (n = 28). The PFS rate at 12 weeks was 61%, and the median survival was 9.2 months. Treatment was generally well tolerated. The most common treatment-related grades 3 to 4 adverse events were diarrhea (19%), neutropenia (10%), rash (7%), and asthenia (6%). The rate of grades 3 to 4 infusion-related reactions (IRRs; composite adverse event category) was 1% for patients who received both antihistamine and corticosteroid premedication. CONCLUSION Tolerability (except IRR incidence), PFS rate, and overall survival rate were in line with previous results. At 1%, the rate of IRRs in patients who received prophylactic premedication with both antihistamine and corticosteroid is lower than previously reported. MABEL clearly confirms in a community practice setting the efficacy and safety of cetuximab plus irinotecan in the treatment of mCRC.

Urgent need for a new staging system in advanced colorectal cancer

Despite recent advances in the medical treatment of metastatic colorectal cancer (mCRC), which include irinotecan- and oxaliplatin-based first-line regimens, the concept of planned sequential therapy involving three active agents during the course of a patient's treatment and the increasing use of targeted monoclonal antibodies, 5-year survival rates for patients with advanced CRC remain unacceptably low. For patients with CRC liver metastases, liver resection remains the only chance of cure, with 5-year survival rates ranging from 25% to 40%. However, 80% to 85% of patients with stage IV CRC have liver disease which is considered unresectable at presentation. The rapid expansion in the use of improved combination chemotherapy regimens plus or minus biologics, to render initially unresectable metastases resectable has increased the percentage of patients eligible for potentially curative surgery. However, the current staging criteria for CRC patients with metastatic disease do not reflect these recent changes or the fact that there is also a large variation in the survival of patients with stage IV CRC. For example the survival for a patient with a solitary, resectable liver metastasis is better than that for a patient with stage III disease. A new staging system is therefore needed that acknowledges both the improvements that have been made in surgical techniques for resectable metastases and the impact of modern chemotherapy on rendering initially unresectable CRC liver metastases resectable, while at the same time distinguishing between patients with a chance of cure at presentation and those for whom only palliative treatment is possible.

Cetuximab in combination with weekly 5-fluorouracil/folinic acid and oxaliplatin (FUFOX) in untreated patients with advanced colorectal cancer: a phase Ib/II study of the AIO GI Group

BACKGROUND

This two-part phase Ib/II study investigated the feasibility of administering cetuximab in combination with oxaliplatin and infusional 5-fluorouracil (5-FU)/folinic acid (FA) in a weekly schedule (AIO FUFOX protocol) as first-line treatment in patients with epidermal growth factor receptor-detectable advanced colorectal cancer.

PATIENTS AND METHODS

Cetuximab was administered weekly: 400 mg/m(2) initial dose, then 250 mg/m(2) and FUFOX: oxaliplatin 50 mg/m(2), FA 500 mg/m(2) and 5-FU as a 24-h infusion at either 1500 or 2000 mg/m(2) administered for 4 weeks followed by a 1-week rest (one cycle).

RESULTS

Dose-limiting toxicity (grade 3 diarrhea) occurred in 3 of 14 assessable patients receiving 5-FU at standard 2000 mg/m(2). This dose was administered to a further 25 patients. Cetuximab combined with FUFOX was generally well tolerated with the most common grade 3/4 adverse events being diarrhea (27%) and paresthesia (16%). The confirmed response rate for patients receiving 5-FU at standard 2000 mg/m(2) (N = 41) was 56%, with a median duration of 9.3 months. Median progression-free and overall survival times including all 49 patients were 8.1 (95% confidence interval 6.0-9.7) and 28.2 months, respectively. Cetuximab pharmacokinetics seemed not to be different for combination with FUFOX compared with cetuximab/irinotecan combinations.

CONCLUSION

This protocol is well tolerated and shows promising efficacy supporting further investigation.

Phase II trial of cetuximab in combination with fluorouracil, leucovorin, and oxaliplatin in the first-line treatment of metastatic colorectal cancer

PURPOSE

This phase II study investigated the efficacy and safety of cetuximab combined with standard oxaliplatin-based chemotherapy (infusional fluorouracil, leucovorin, and oxaliplatin [FOLFOX-4]) in the first-line treatment of epidermal growth factor receptor-expressing metastatic colorectal cancer (mCRC).

PATIENTS AND METHODS

The activity of cetuximab plus oxaliplatin was investigated in colon cancer cell lines and xenograft models. In the clinical study, patients with mCRC received on day 1 of a 14 day cycle, cetuximab (initial dose 400 mg/m(2) during week 1, then 250 mg/m(2) weekly) followed by FOLFOX-4 (oxaliplatin 85 mg/m(2) on day 1; leucovorin 200 mg/m(2) on days 1 and 2, followed by fluorouracil 400 mg/m(2) bolus then 600 mg/m(2) intravenous infusion during 22 hours on days 1 and 2).

RESULTS

The preclinical studies confirmed the supra-additive activity of cetuximab to oxaliplatin. In the clinical study, 43 patients were included, with a median age of 65 years (range, 43 to 78 years). Response rates (RRs) were 79% (unconfirmed) and 72% (confirmed), with 95% disease control. Median progression-free survival (mPFS) and median duration of response were 12.3 and 10.8 months, respectively. Ten patients (23%) underwent resection with curative intent of previously unresectable metastases. After a median follow-up of 30.5 months, median overall survival (mOS) was 30.0 months. Cetuximab did not increase the characteristic toxicity of FOLFOX-4 and was generally well tolerated.

CONCLUSION

Cetuximab in combination with FOLFOX-4 is a highly active first-line treatment for mCRC, showing encouraging RR, mPFS, and mOS values. The treatment resulted in a high resectability rate, which could potentially result in an improved cure rate. This combination is under phase III development.