Purpose: BBR 3464 is a novel trinuclear platinum anticancer agent with a broad spectrum of preclinical antitumour activity. A phase I, open-label dose-escalating study was performed to determine the maximum tolerated dose (MTD) of BBR 3464 administered in combination with protracted venous infusional (PVI) 5-fluorouracil (5-FU) for up to six courses in patients with locally advanced and/or metastatic cancer.
Methods: Dose escalation was based on observation of toxicity at each dose level. BBR 3464 (0.6 mg/m(2) escalated to 0.75 mg/m(2)) was studied in combination with PVI 5-FU (200 mg/m(2) per day).
Results: Entered into the study were 14 patients. The most frequent toxicities were nausea, neutropenia, fatigue and diarrhoea. The protocol-defined MTD was not determined as 11/14 patients experienced grade 3 or 4 neutropenia that interrupted the planned administration of PVI 5-FU on day 15 (of 21). Although these events were not dose-limiting, as defined in the protocol, they imposed limitations on the dose of PVI 5-FU administered. Antitumour activity was observed: a partial response in one patient (7%) with invasive breast cancer. Stable disease was confirmed in three patients (21%). These four patients all completed the planned six courses of combined therapy.
Conclusions: In light of the lack of septic events associated with the recorded neutropenia, it may be possible to safely continue PVI 5-FU despite the grade 3 or 4 neutropenia or modify the PVI schedule and administer therapy on days 1-15 of the 21-day cycle, but these modifications were not considered in this study.