Kuttesch, John F.

AbstractBackgroundPatients with alveolar rhabdomyosarcoma (ARMS) have inferior outcomes compared to patients with embryonal rhabdomyosarcoma (ERMS) and more effective chemotherapy options are needed for these patients. Vinorelbine is a semisynthetic vinca alkaloid that has clinical activity in relapsed rhabdomyosarcoma (RMS) when used alone or in combination with cyclophosphamide.AimsThe goal of our study was to evaluate whether RMS histology subtype influences response rate to vinorelbine alone or in combination.Materials & MethodsFive Phase 2 trials that enrolled RMS patients were included in the meta‐analysis. Two studies evaluated vinorelbine alone, two studies evaluated vinorelbine in combination with low dose oral cyclophosphamide, and one study evaluated vinorelbine and intravenous cyclophosphamide in combination with temsirolimus or bevacizumab. All RMS patients had relapsed or refractory disease and had received at least one prior therapy. Response was reported according to RECIST1.1 and was defined as a complete or partial response. Response data was obtained from published results or from trial principal investigator. RMS NOS patients were grouped with ERMS patients for this analysis. Summary estimates comparing differences between ARMS and ERMS response rates were generated using a random‐effects model to account for heterogeneity among the studies.ResultsOne hundred fifty‐six enrolled patients evaluable for response were included in the meta‐analysis, 85 ARMS, 64 ERMS and 7 RMS‐NOS. The combined effect generated from the random‐effects model demonstrated a 41% increase (p = 0.001, 95% CI; 0.21–0.60) in response to vinorelbine as a single agent or in combination in patients with ARMS compared to patients with ERMS. There was no significant difference in the rate of progressive disease between patients with ARMS compared to ERMS (p = 0.1, 95%CI; −0.26–0.02).DiscussionVinorelbine is an active agent for the treatment of relapsed or refractory RMS and a meta‐analysis of Phase 2 studies shows that radiographic responses in patients with ARMS were significantly higher than ERMS or RMS‐NOS.ConclusionThese data support further investigation of vinorelbine in newly diagnosed patients with RMS particularly those with alveolar histology.

Abstract Purpose: Vinorelbine (Navelbine) is an orally absorbable Vinca with broad antitumor activity. It differs from other Vinca in that it is structurally modified on the catharanthine nucleus and has differential actions on tubulin that render it less neurotoxic than other compounds in this class. We conducted a phase I study of vinorelbine given the activity of Vinca alkaloids in many pediatric tumors. Experimental Design: We evaluated the safety and pharmacokinetics of oral and i.v. vinorelbine administered weekly × 6 in children (age, 2-17 years) with different tumors. Patients with disease involvement in the bone marrow were eligible but were stratified and dose-escalated separately. Oral vinorelbine (week 1) was administered as liquid-filled gelatin capsules at thrice the i.v. dose. Intravenous vinorelbine doses of 24 to 37.5 mg/m2 were administered on weeks 2 to 6. Results: The dose-limiting toxicity in patients without marrow involvement was reversible neutropenia. Common nonhematologic toxicities included ≤ grade 2 nausea/vomiting and increased hepatic transaminases. A higher mean i.v. ClTB was observed (1.75 ± 1.0 L/h/kg) compared with adult reports, with a mean t1/2B of 16.5 ± 9.7 hours. Mean oral bioavailability was 28.5 ± 22.5%. The apparent oral clearance (12.1 ± 13.0 L/h/kg) and volume of distribution (69.4 ± 30.6 L/kg) were substantially higher than in adults given similar oral doses. Conclusions: The maximum tolerated dose in children without bone marrow involvement was 30 mg/m2, similar to that reported in adults, with myelosuppression being the dose-limiting toxicity. Higher plasma clearance resulted in lower area under the plasma concentration-time curves at a given dose compared with that reported in adults.

Purpose To determine the maximum tolerated dose, toxicity, and pharmacokinetics of gemcitabine in children with refractory solid tumors. Patients and Methods 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 1,000, 1,200 and 1,500 mg/m2 were administered for 3 weeks. Subsequently, gemcitabine was given for only 2 consecutive weeks at 1,500, 1,800, and 2,100 mg/m2. Plasma concentrations of gemcitabine and its metabolite, 2′2′-difluorodeoxyuridine, were measured in 28 patients. Results Forty patients who received 132 courses of gemcitabine were assessable for toxicity. The maximum tolerated dose of gemcitabine given weekly for 3 weeks was 1,200 mg/m2. 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 1,500 mg/m2 for 3 weeks, and one of seven patients at 1,800 mg/m2 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 2,140 mL/min/m2 and 13.7 minutes, respectively. One patient with pancreatic cancer had a partial response. Seven patients had stable disease for 2 to 17 months. Conclusion Gemcitabine given by 30-minute infusion for 2 or 3 consecutive weeks every 4 weeks was tolerated well by children at doses of 2,100 mg/m2 and 1,200 mg/m2, respectively.