Phase I study of gefitinib, oxaliplatin, 5-fluorouracil, and leucovorin (IFOX) in patients with advanced solid malignancies.

PURPOSE

Aphase 1 study of gefitinib in combination with oxaliplatin, 5-fluorouracil and leucovorin (IFOX)was conducted to evaluate the safety and feasibility of this regimen.

PATIENTS AND METHODS

Patients with advanced solid malignancies were treated with escalating doses of gefitinib (250 mg or 500 mg once daily) in combination with FOLFOX (oxaliplatin, 5-fluorouracil, and leucovorin). The initial dose of oxaliplatin was 70 mg/m2 with sequential dose escalation to 85 mg/m2.

RESULTS

Sixteen patients received a total of 138 14-day courses of daily gefitinib in combination with FOLFOX. Escalation of gefitinib from 250 mg/d to 500 mg/d with FOLFOX was well-tolerated. In addition, no severe toxicities precluded subsequent dose escalation of oxaliplatin from 70 mg/m2 to 85 mg/m2 at which no dose-limiting toxicity was seen. No further dose escalation was performed as this represented the oxaliplatin dose administered in the standard FOLFOX-4 regimen. The most predominant toxicity was diarrhea, which was well controlled with oral antidiarrheal agents. Four partial remissions occurred in patients with metastatic colorectal cancer.

CONCLUSIONS

Gefitinib as a 500 mg daily continuous dose was well tolerated in combination with full doses of FOLFOX-4.