A Phase I/II Study of Docetaxel, Oxaliplatin, and Fluorouracil (D-FOX) Chemotherapy in Patients with Untreated Locally Unresectable or Metastatic Adenocarcinoma of the Stomach and Gastroesophageal Junction

Background: A randomized phase III study established docetaxel, cisplatin, and 5-fluorouracil (DCF) as one of the standard treatments for patients with untreated advanced gastric cancer (AGC). However, DCF use is limited due toxicity. With the purpose to evaluate a less toxic regimen, we conducted a single arm, phase I/II trial of modified DCF (oxaliplatin, 5-fluorouracil, and docetaxel [D-FOX]) for untreated AGC patients. The primary objective of the phase I study was to determine the maximum tolerated dose of docetaxel and for the phase II study was to assess the progression-free survival (PFS) at 6 months and overall survival (OS). Patients and Methods: We enrolled a total of 98 patients with AGC. Docetaxel and oxaliplatin were administered intravenously on day 1 and 5-fluorouracil was infused starting on day 1 over 48 hours. Cycles were repeated every 2 weeks and patients were monitored for toxicities. Kaplan-Meir curve was used to estimate unadjusted OS and PFS. Results: The maximum tolerated dose of docetaxel was 50 mg/m². In total, 24 (45%) patients experienced grade 2 adverse events, 22 (41%) experienced grade 3, and 1 (1.9%) experienced grade 4 toxicity. The median PFS in the phase II portion of the study was approximately 6.5 (95% confidence interval, 5.5-9.5) months and the median OS was 11.1 (95% confidence interval, 9.4-18.8) months. Conclusions: D-FOX administered every 2 weeks is a well-Tolerated and active regimen in untreated AGC patients.