Axitinib dose titration: analyses of exposure, blood pressure and clinical response from a randomized phase II study in metastatic renal cell carcinoma.

BACKGROUND: In a randomized, double-blind phase II trial in patients with metastatic renal cell carcinoma (mRCC), axitinib versus placebo titration yielded a significantly higher objective response rate. We evaluated pharmacokinetic and blood pressure (BP) data from this study to elucidate relationships among axitinib exposure, BP change, and efficacy. PATIENTS AND METHODS: Patients received axitinib 5 mg twice daily during a lead-in period. Patients who met dose-titration criteria were randomized 1:1 to stepwise dose increases with axitinib or placebo. Patients ineligible for randomization continued without dose increases. Serial 6-h and sparse pharmacokinetic sampling were carried out; BP was measured at clinic visits and at home in all patients, and by 24-h ambulatory BP monitoring (ABPM) in a subset of patients. RESULTS: Area under the plasma concentration-time curve from 0 to 24 h throughout the course of treatment (AUCstudy) was higher in patients with complete or partial responses than those with stable or progressive disease in the axitinib-titration arm, but comparable between these groups in the placebo-titration and nonrandomized arms. In the overall population, AUCstudy and efficacy outcomes were not strongly correlated. Mean BP across the population was similar when measured in clinic, at home, or by 24-h ABPM. Weak correlations were observed between axitinib steady-state exposure and diastolic BP. When grouped by change in diastolic BP from baseline, patients in the ≥10 and ≥15 mmHg groups had longer progression-free survival. CONCLUSIONS: Optimal axitinib exposure may differ among patients with mRCC. Pharmacokinetic or BP measurements cannot be used exclusively to guide axitinib dosing. Individualization of treatment with vascular endothelial growth factor receptor tyrosine kinase inhibitors, including axitinib, is thus more complex than anticipated and cannot be limited to a single clinical factor.

Taking a bite out of CRISP. Strategies on using and conducting searches in the Computer Retrieval of Information on Scientific Projects database.

A vast array of information useful to the scientific community is readily available on the internet. Currently, the National Institutes of Health (NIH) offers user access to several large databases, some of which are pertinent to nurses interested in research, health policy formation, and identifying funded research projects. One such database, the Computer Retrieval of Information on Scientific Projects (CRISP), provides information on research grants funded by the NIH from 1972 to the present. Retrieval of scientific information for each project in CRISP is made available by project title, grant number, abstract, principal investigator, eight-digit CRISP Thesaurus terms, and key words. This article introduces the reader to CRISP and provides a set of succinct strategies for conducting comprehensive searches in the database.