Oxaliplatin (LOHP) and 5-fluorouracil (5-FU) synergism in advanced colorectal cancer patients (ACRC)

Pemetrexed/Oxaliplatin for First-Line Treatment of Patients with Advanced Colorectal Cancer: A Phase II Trial of the National Surgical Adjuvant Breast and Bowel Project Foundation Research Program

BACKGROUND

Pemetrexed and oxaliplatin have clinical activity as single agents in colorectal cancer (response rates, 10%-17%). In this study, these drugs were used in combination as first-line therapy in a group of patients with metastatic colorectal cancer.

PATIENTS AND METHODS

Fifty-four evaluable patients were to receive pemetrexed (500 mg/m2) with folic acid and vitamin B12 supplementation and oxaliplatin (120 mg/m2) every 21 days for 6 cycles or until disease progression occurred. Patients with stable or responding disease could continue therapy beyond 6 cycles at the discretion of the investigator. Eligibility criteria included a diagnosis of untreated metastatic adenocarcinoma of the colon or rectum, measurable disease, Zubrod performance status <or=2, no adjuvant chemotherapy within 6 months, and >or=12 weeks life expectancy.

RESULTS

The confirmed clinical response rate (primary endpoint) was 29.6% (95% confidence interval [CI], 18%-48.6%), with 1 complete response and 15 partial responses. Median time to progression was 5.3 months (95% CI, 3.9-6.3 months), and median survival was 12.3 months (95% CI, 8.6-17 months). Grade 3/4 nadir neutropenia occurred in 33.3% of patients, and 3 patients experienced grade 3 febrile neutropenia or infection associated with grade 3/4 neutropenia. Grade 3/4 nadir thrombocytopenia was seen in 11.1% of patients. Only 4% of the patients developed grade 3/4 neurotoxicity.

CONCLUSION

This regimen of pemetrexed and oxaliplatin has activity in advanced colorectal cancer, and the toxicity profile suggests that escalation of the dose of pemetrexed in this combination may be possible.

Factors predicting for efficacy of oxaliplatin in combination with 5-fluorouracil (5-FU)+/-folinic acid (FA) in a compassionate-use cohort of 370 5-FU-resistant advanced colorectal cancer (CRC) patients

Univariate and multivariate analyses were performed on data from 370 5-fluorouracil (5-FU)-resistant advanced colorectal cancer patients treated with oxaliplatin (Eloxatin)/5-FU+/-folinic acid (FA) to identify prognostic factors for oxaliplatin-based treatment. The response rate was 14.6% (95% confidence interval (CI): 11.0-18.2%), median time to progression was 4.3 months (95% CI: 3.9-4.7), and median overall survival 9.7 months (95% CI: 8.5-10.8). Multivariate analysis indicated < 2 prior chemotherapy regimens, bi-weekly treatment administration schedule (versus tri-weekly) and continuous chronomodulated delivery (CCM) as significantly associated (P < 0.05) with a higher overall response rate. Performance status (PS) < 2, having only one involved organ, biweekly schedule and CCM were associated (P < 0.05) with a longer time to progression. Good PS, one involved organ, low alkaline phosphatase (AP) serum levels, bi-weekly schedule and CCM were significantly correlated with longer overall survival, while confirming the efficacy of oxaliplatin/5-FU+/-FA in this indication.

Oxaliplatin clinical activity: a review

Oxaliplatin (Eloxatin), a recently developed third-generation cisplatin analogue with a 1,2-diaminocyclohexane (DACH) carrier ligand, has displayed preclinical and clinical activity in a wide variety of tumour types. Synergistic with 5-FU in colorectal cancer (CRC), the combination has proven efficacy in 5-FU-resistant advanced disease and in previously untreated CRC, as demonstrated in controlled phase III trials, while evaluation in the adjuvant setting is ongoing. Due to its excellent safety profile, its unique mechanism of action and lack of cross-resistance with other active agents in CRC, oxaliplatin has also been combined with CPT-11 and Raltitrexed with promising results. Trials in pretreated and untreated advanced ovarian cancer (AOC), as a single agent or in combination with cisplatin, cyclophosphamide or paclitaxel, indicate a yet to be defined role in AOC and confirm its lack of cross-resistance with cis/carboplatin. Clinical investigations of single agent and combination therapies in breast, lung, prostate and germ-cell carcinomas, non-Hodgkin's lymphoma and malignant mesothelioma are being pursued. While the role of oxaliplatin in medical oncology is yet to be fully defined, it appears to be an important new anticancer agent.