[Clinical development in gemcitabine and its clinical pharmacological profile]

Gemcitabine Hydrochloride (hereafter: Gemcitabine) is a new anti-tumor agent being widely used in other countries for treatment of non-small cell lung cancer was recently approved in Japan. The profile of Gemcitabine is considered to be the following 2 points both for non-small cell lung cancer and for pancreatic cancer, of which the study is currently conducted in Japan: high efficacy as foreign data indicate prolongation of survival time and less frequency of serious adverse reactions than other conventional anti-tumor agents. According to the results of Japanese and foreign phase I studies, as clinical pharmacological profile of Gemcitabine, its elimination half-life is rather short such as 20 minutes. Weekly administration by injection over 30 minutes is appropriate since bone marrow suppression and hepatic disorder were frequently observed in case of administration twice a week or injection for more than 60 minutes. Also, population pharmacokinetics results showed a tendency that blood plasma clearance of Gemcitabine was lower in women and aged patients. Dose adjustment depending on gender is not considered to be necessary because the blood plasma clearance amount of Gemcitabine is large enough itself. However, influence caused by aging must be observed continuously in the future. For its profile of mild adverse reactions of Gemcitabine mentioned above, concomitant chemotherapy with other anti-tumor agents is expected be widely conducted in the future, therefore, clinically pharmacological observation of Gemcitabine is important for its appropriate use as well.