A strategy for rapid and easy measurement of plasma concentration of pazopanib.

Abstract

Molecular-targeted anticancer drugs are administrated for any patients in a fixed-dose. The plasma concentration considerably varies among individuals, inducing serious adverse events in some occasions. Recent studies showed relevance of the plasma drug level to the efficacy and toxicity. Nevertheless, the measurement at clinical sites has not yet been fully achieved, owing to lack of the rapid and easy method. To address this issue, we developed a strategy with an electrochemical sensor composed of conductive diamond. Initially, rat plasma mixed in advance with pazopanib was tested. Linear concentration-dependent response was observed along the therapeutic window. Each measurement took ~35 s, and the process was completed in ~10 min. Next, from rats orally administered with pazopanib, and blood of < 60 μL were longitudinally sampled multiple times. Measured T_max was ~4 hours, as described in the literature. Finally, we constructed a portable, palm-size device. These approaches accelerate tailored medicine for cancer.