To determine the maximum tolerated dose (MTD), toxicities, and suitable dose for weekly 1-h paclitaxel combined with weekly cisplatin and irinotecan to treat advanced gastrointestinal malignancies.
Thirty patients with metastatic or locally advanced (unresectable or recurrent) gastrointestinal solid tumors were enrolled on this single-center, phase I study. Patients were treated with paclitaxel given over 1h at 1 of 4 dose levels (40, 50, 65, or 80 mg/m2). Paclitaxel was followed by fixed doses of cisplatin (30 mg/m2) and irinotecan (50 mg/m2). All treatment was administered sequentially, once a week, in 6-week cycles (4 weeks on, 2 weeks off). Dose-limiting toxicity (DLT) was defined as a 2-week delay in treatment for grade 3 or 4 non-hematologic toxicity, neutropenic fever, a 1-week delay for grade 4 hematologic toxicity, or a 2-week delay for grade 3 hematologic toxicity.
Thirty patients were recruited; 28 patients were assessable for safety. Most of the patients (70%) had no prior chemotherapy. The primary first-cycle DLTs were neutropenia, diarrhea, and nausea. Paclitaxel at 65 mg/m2 was defined as the MTD. The most common grade 3–4 toxicities observed during all cycles were neutropenia (57%), febrile neutropenia (11%), diarrhea (29%), fatigue (29%), and nausea (18%). No patients had G-CSF (Neupogen, Amgen Inc., Thousand Oaks, CA) support. Responses were observed in gastric, esophageal, and pancreatic cancers.
Paclitaxel at 65 mg/m2, cisplatin (30 mg/m2), and irinotecan (50 mg/m2) given weekly can be safely administered to patients with solid tumor malignancies. To improve cumulative toxicities, a schedule modification was required (3-week cycle; 2-on, 1-off) Neutropenia was the most common DLT. This combination showed substantial activity, particularly in patients with gastric and esophageal adenocarcinoma, and phase II evaluation could be considered.