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Abstract Purpose: Loss of PTEN, which is common in glioblastoma multiforme (GBM), results in activation of the mammalian target of rapapmycin (mTOR), thereby increasing mRNA translation of a number of key proteins required for cell-cycle progression. CCI-779 is an inhibitor of mTOR. The primary objectives of this study were to determine the efficacy of CCI-779 in patients with recurrent GBM and to further assess the toxicity of the drug. Experimental Design: CCI-779 was administered weekly at a dose of 250 mg intravenously for patients on enzyme-inducing anti-epileptic drugs (EIAEDs). Patients not on EIAEDs were initially treated at 250 mg; however, the dose was reduced to 170 mg because of intolerable side effects. Treatment was continued until unacceptable toxicity, tumor progression, or patient withdrawal. The primary endpoint was 6-month progression-free survival. Results: Forty-three patients were enrolled; 29 were not on EIAEDs. The expected toxicity profile of increased lipids, lymphopenia, and stomatitis was seen. There were no grade IV hematological toxicities and no toxic deaths. One patient was progression free at 6 months. Of the patients assessable for response, there were 2 partial responses and 20 with stabilization of disease. The median time to progression was 9 weeks. Conclusions: CCI-779 was well tolerated at this dose schedule; however, there was no evidence of efficacy in patients with recurrent GBM. Despite initial disease stabilization in approximately 50% of patients, the durability of response was short. Because of the low toxicity profile, CCI-779 may merit exploration in combination with other modalities. [ABSTRACT FROM AUTHOR]

Objectives: CCI-779 is an ester of the immunosuppressive agent sirolimus (rapamycin) that causes cell-cycle arrest at G1 via inhibition of key signaling pathways resulting in inhibition of RNA translation. Antitumor activity has been demonstrated using cell lines and animal models of malignant glioma. Patients receiving enzyme-inducing anti-epileptic drugs (EIAEDs) can have altered metabolism of drugs like CCI-779 that are metabolized through the hepatic cytochrome P450 enzyme system. The objectives of this study were to determine the pharmacokinetic profile and the maximum tolerated dose of CCI-779 in patients with recurrent malignant gliioma taking EIAEDs. Study design: The starting dose of CCI-779 was 250 mg intravenously (IV) administered weekly on a continuous basis. Standard dose escalation was performed until the maximum tolerated dose was established. Toxicity was assessed using the National Cancer Institute common toxicity criteria. Results: Two of 6 patients treated at the second dose level of 330 mg sustained a dose-limiting toxicity: grade III stomatitis, grade 3 hypercholesterolemia, or grade 4 hypertriglyceridemia. The maximum tolerated dose was reached at 250 mg IV. Pharmacokinetic profiles were similar to those previously described, but the area under the whole blood concentration-time curve of rapamycin was 1.6 fold lower for patients on EIAEDs. Conclusions: The recommended phase II dose of CCI 779 for patients on enzyme-inducing antiepileptic drugs is 250 mg IV weekly. A phase II study is ongoing to determine the efficacy of this agent. [ABSTRACT FROM AUTHOR]

To determine the safety and evaluate the efficacy of repeated administration of virus-producing cells (GLI 328) containing the herpes simplex virus thymidine-kinase gene followed by ganciclovir treatment in adults with recurrent glioblastoma multiforme, we conducted a phase I/II multi-institutional trial. Eligible patients underwent surgical resection of tumor, followed by injections of vector producing cells (VPC) into the brain adjacent to the cavity. An Ommaya reservoir placed after surgery was used to inject a further dose of VPC seven days after surgery, followed seven days later by ganciclovir. Further gene therapy was given at 28-day intervals for up to a total of five cycles. Toxicity and anti-tumor effect were assessed. Of 30 patients who enrolled in the study, 16 experienced serious adverse events possibly related to the experimental therapy. Laboratory testing, including polymerase chain reaction analysis to detect replication-competent retrovirus in peripheral blood lymphocytes and tissues, as well as co-cultivation bioassays, were negative. Before receiving ganciclovir, 37% of the patients showed evidence of transduced peripheral blood leukocytes, but only 12% showed a persistence of transduced cells at the end of the first cycle of ganciclovir. Median survival was 8.4 months. Twenty percent of the patients (n = 6) survived more than 12 months from the date of study entry. This treatment modality is feasible and appears to have some evidence of efficacy. Toxicity may be related in part to the method of gene delivery. [ABSTRACT FROM AUTHOR]

Purpose: To compare two different infusion schedules of phenylacetate (PA) in patients with primary brain tumors and to assess the feasibility of the administration in a multi-institutional setting. Patients and methods: Adult patients with recurrent primary brain tumors were treated with PA on two different schedules. The first schedule (I) consisted of a 2-week continuous, intravenous infusion followed by a 2-week rest period (14 days on, 14 days off) at a dose of 400 mg/kg/day based on ideal body weight. This was repeated once and the 8-week period defined as a cycle. The second schedule (II) consisted of a 12-day continuous infusion at a dose of 400 mg/kg/day based on IBW with a 2-day rest period. This was repeated four times for a duration of 8 weeks which defined one cycle of therapy. Cycles were repeated until tumor progression, unacceptable toxicity, or a delay of more than 28 days from the last day of the preceding infusion. Tumor response was assessed every 8 weeks. The National Cancer Institute toxicity criteria were used to assess toxicity. Dose adjustments were specified for toxicities. Plasma concentrations achieved during the patients'' first cycle of therapy were assessed. Results: The clinical results of the phase II study of patients treated on schedule I were previously reported [8]. Of the nine eligible patients treated on schedule II, seven were assessable for radiographic response. There were no objective responses. One patient had stable disease and six had progressive disease. The median survival was 9 months (95% confidence intervals of 3–12 months). The steady state plasma concentrations of PA and phenylacetylglutamine were comparatively the same between the two dosing schedules. However a 1.7-fold greater amount of PA was delivered by schedule II. Conclusion: The infusions were well tolerated. Despite the feasibility of administering this agent in an outpatient setting, there were no responses seen with the more intensive schedule of PA. [ABSTRACT FROM AUTHOR]