Phase I trial and pharmacokinetics of gemcitabine in children with advanced solid tumors

To determine the maximum tolerated dose, toxicity, and pharmacokinetics of gemcitabine in children with refractory solid tumors.

Gemcitabine was given as a 30-minute infusion for 2 or 3 consecutive weeks every 4 weeks, to 42 patients aged 1 to 21 years. Doses of 1000, 1200 and 1500 mg/m(2) were administered for 3 weeks. Subsequently, gemcitabine was given for only 2 consecutive weeks at 1500, 1800, and 2100 mg/m(2). Plasma concentrations of gemcitabine and its metabolite, 2'2'-difluorodeoxyuridine, were measured in 28 patients.

Forty patients who received 132 courses of gemcitabine were assessable for toxicity. The maximum tolerated dose of gemcitabine given weekly for 3 weeks was 1200 mg/m(2). Dose-limiting toxicity was not seen in one-third of children treated at any doses given for 2 weeks. The major toxicity was myelosuppression in three of five patients at 1500 mg/m(2) for 3 weeks, and one of seven patients at 1800 mg/m(2) for 2 weeks. Other serious adverse events were somnolence, fever and hypotension, and rash in three patients. Gemcitabine plasma concentration-time data were fit to a one- (n = 5) or two-compartment (n = 23) open model. Mean gemcitabine clearance and half-life values were 2140 mL/min/m(2) and 13.7 minutes, respectively. One patient with pancreatic cancer had a partial response. Seven patients had stable disease for 2 to 17 months.

Gemcitabine given by 30-minute infusion for 2 or 3 consecutive weeks every 4 weeks was tolerated well by children at doses of 2100 mg/m(2) and 1200 mg/m(2), respectively.