Primary Outcome Measures:
- Evaluate the safety and tolerability of high dose IV vitamin C as a monotherapy
- Evaluate the pharmacokinetic profile of IV vitamin C at varying doses
Secondary Outcome Measures:
- Determine if vitamin C accumulates with repeated daily therapy by measuring peak and nadir levels
- Evaluate patient quality of life
- Observe patients for clinical and radiological evidence of anti-tumor activity at the end of treatment
Preclinical studies of pharmacologic doses of vitamin C (ascorbic acid, ascorbate) have shown significant anticancer effects in animal models and tissue culture investigations including cytotoxic effects in certain cancer cell lines at micromolar to millimolar concentrations.
Early clinical studies have shown that intravenous and oral doses of vitamin C may improve symptoms and prolong survival in terminal cancer patients. More recent double-blind placebo-controlled studies have shown that oral adminstration of vitamin C provides no benefit to cancer patients. Conversely, intravenous vitamin C administration raises plasma concentrations as high as 14 mM/L, and concentrations of 1-5 mM/L have been found to be selectively cytoxic to tumor cells in vitro.
The proposed Phase I trial with vitamin C should achieve millimolar concentrations of vitamin C that have been shown to kill tumor cells in vitro. The maximum tolerated dose (MTD), PK, possible drug accumulation with repeated dosing, quality of life, pain response, fatigue status, and hints of efficacy in patients with advanced cancer will be examined.
Purpose
