Pharmacokinetically Guided Everolimus in Patients With Breast Cancer, Pancreatic Neuroendocrine Tumors, or Kidney Cancer

PRIMARY OBJECTIVE: To determine frequency of any grade of stomatitis at day 29 (cycle 2, day 1) in patients receiving dose-adjusted everolimus. SECONDARY OBJECTIVES: 1. Progression-free survival rates at 6 months. 2. Pharmacodynamic (PD)-inhibition of downstream mammalian target of rapamycin (mTOR) effectors in peripheral blood. 3. Number of dose adjustments required. 4. Percentage of days on therapy. 5. Average minimum concentration (Cmin) values. 6. Frequency and type of treatments for stomatitis. 7. Genetic predictors of stomatitis development in selected outlier patients. OUTLINE: Patients receive everolimus orally (PO) daily on days 1-28. Treatment repeats every 28 days for up to 6 courses in the absence of disease progression or unacceptable toxicity. Patients also undergo real-time pharmacokinetic therapeutic drug monitoring (TDM) on days 4, 8, and 15 of course 1. Dosing adjustments of everolimus will be performed on day 8, if necessary. If the everolimus dose is adjusted, patients will continue to undergo real-time pharmacokinetic TDM weekly until goal concentrations are achieved on 2 consecutive measures. Patients whose everolimus dose is not adjusted undergo real-time pharmacokinetic TDM on day 1 of courses 2-6. After completion of study treatment, patients are followed up every 12 weeks.