Purpose: To evaluate safety and pharmacokinetics and to establish the maximum tolerated dose of glufosfamide when administered in combination with gemcitabine in advanced solid tumors.
Methods: This Phase 1 dose-escalation study evaluated the combination of glufosfamide + gemcitabine in patients with advanced solid tumors. Cohorts of three to six patients were treated with glufosfamide doses from 1,500 to 4,500 mg/m(2) i.v. over 4 h on Day 1 and gemcitabine 1,000 mg/m(2) i.v. over 30 min on Days 1, 8 and 15 of every 28-day cycle. Detailed PK sampling was performed on days 1 and 8 of the first two cycles.
Results: Nineteen patients were enrolled. Two patients had dose-limiting toxicity: Grade 3 fatigue at 2,500 mg/m(2) and Grade 4 thrombocytopenia at 4,500 mg/m(2). Five patients completed six cycles and one patient remained on study for ten cycles. Two patients discontinued for adverse events. Grade 3/4 neutropenia and thrombocytopenia occurred in seven patients and five patients, respectively. The CrCL fell below 60 mL/min in two patients. There was one unconfirmed partial response and 10 of 19 (52.6%) patients had stable disease or better at 8 weeks and three patients had continuing stable disease at 24 weeks. Pharmacokinetic analyses suggest no interaction between glufosfamide and gemcitabine.
Conclusion: Phase I data indicate that full dose glufosfamide (4,500 mg/m(2)) can be given safely in combination with gemcitabine. A Phase II study in patients with pancreatic adenocarcinoma is ongoing.