An international expanded-access programme of everolimus: addressing safety and efficacy in patients with metastatic renal cell carcinoma who progress after initial vascular endothelial growth factor receptor-tyrosine kinase inhibitor therapy.

BACKGROUND AND OBJECTIVES: The RECORD-1 trial established the clinical benefit of everolimus in patients with metastatic renal cell carcinoma (mRCC) after failure of initial vascular endothelial growth factor receptor-tyrosine kinase inhibitor (VEGFr-TKI) therapy. The REACT (RAD001 Expanded Access Clinical Trial in RCC) study was initiated to address an unmet medical need by providing everolimus prior to commercial availability, and also to further assess the safety and efficacy of everolimus in patients with VEGFr-TKI-refractory mRCC. PATIENTS AND METHODS: REACT (Clinicaltrials.gov: NCT00655252) was a global, open-label, expanded-access programme in patients with mRCC who were intolerant of, or who had progressed on or after stopping treatment with, any available VEGFr-TKI therapy. Patients received everolimus 10mg once daily, with dose and schedule modifications allowed for toxicity. Patients were closely monitored for the development of serious and grades 3/4 adverse events (AEs). Response was assessed by RECIST every 3months for the first year and every 6months thereafter. RESULTS: A total of 1367 patients were enroled. Safety findings and tumour responses were consistent with those observed in RECORD-1, with no new safety issues identified. The most commonly reported serious AEs were dyspnoea (5.0%), pneumonia (4.7%) and anaemia (4.1%), and the most commonly reported grades 3/4 AEs were anaemia (13.4%), fatigue (6.7%) and dyspnoea (6.5%). Best overall response was stable disease in 51.6% and partial response in 1.7% of patients. Median everolimus treatment duration was 14weeks. CONCLUSION: Everolimus is well tolerated in patients with mRCC and demonstrates a favourable risk-benefit ratio.

Imatinib mesylate (STI571) for treatment of children with Philadelphia chromosome-positive leukemia: results from a Children's Oncology Group phase 1 study.

The purpose of this study was to determine dose-limiting toxicities and pharmacokinetics of imatinib in children with refractory or recurrent Philadelphia chromosome-positive (Ph(+)) leukemias. Oral imatinib was administered daily at dose levels ranging from 260 to 570 mg/m(2). Plasma pharmacokinetic studies were performed on days 1 and 8 of course 1. There were 31 children who received 479 courses of imatinib. The most common toxicities encountered, which occurred in less than 5% of courses, were grade 1 or 2 nausea, vomiting, fatigue, diarrhea, and reversible increases in serum transaminases. One patient at the 440-mg/m(2) dose level had dose-limiting weight gain. There were no other first-course dose-limiting toxicities. A maximum tolerated dosage was not defined. Among 12 chronic myeloid leukemia (CML) patients evaluable for cytogenetic response, 10 had a complete response and 1 had a partial response. Among 10 acute lymphoblastic leukemia (ALL) patients evaluable for morphologic response, 7 achieved an M1 and 1 achieved an M2 bone marrow. We observed marked interpatient variability in the pharmacokinetic parameters. In conclusion, we found that daily oral imatinib is well tolerated in children at doses ranging from 260 to 570 mg/m(2). Doses of 260 and 340 mg/m(2) provide systemic exposures similar to those of adults who are treated with daily doses of 400 and 600 mg, respectively.

Pharmacokinetics and pharmacodynamics of imatinib in a phase I trial with chronic myeloid leukemia patients.

PURPOSE: To evaluate the basic pharmacokinetic (PK) characteristics of imatinib mesylate and assess the relationship between the PK and pharmacodynamic (PD) properties of the drug. PATIENTS AND METHODS: The PK and PD properties of imatinib were investigated during a phase I trial that included 64 adult patients with Philadelphia chromosome-positive leukemias. Patients received imatinib orally once or twice daily. PK parameters of imatinib, derived from the plasma concentration-time curves, were determined. PD response, defined as the WBC after 1 month of treatment with imatinib, was used to develop an efficacy model. A maximum inhibition-effect model was used to describe the relationship between reduction in WBC and drug exposure parameters. RESULTS: Imatinib exposure was dose proportional after oral administration for the dose range of 25 to 1,000 mg. There was a 1.5- to three-fold drug accumulation after repeated once-daily dosing. Mean plasma trough concentration was 0.57 microg/mL (approximately 1 micromol/L) 24 hours after administration of 350 mg of imatinib at steady-state, which exceeds the 50% inhibitory concentration required to inhibit proliferation of Bcr-Abl-positive leukemic cells. Analysis of PK/PD relationships indicates that the initial hematologic response depends on the administered dose for patients with chronic myeloid leukemia. CONCLUSION: Drug exposure (area under the concentration-time curve) is dose proportional for the dose range of 25 to 1,000 mg, and there is a 1.5- to three-fold drug accumulation at steady-state after once-daily dosing. Analysis of the relationship between PD (WBC reduction) and PK parameters at steady-state indicates that a dose of 400 mg or greater is required for maximal PD effect.