Antitumor activity of ormustine against transplantable solid murine tumors. Part I
Background. Drugs of nitrosourea class are actively and successfully administered in oncology practice. However, at present, the search for new antitumor agents of this class is very urgent. Objective: to examine in vivo antitumor activity of ormustine, a new Russian drug from alkylnitrosourea class, against solid transplantable murine tumors: melanoma B16 and epidermoid Lewis lung carcinoma. Materials and methods. The assessment of antitumor activity of ormustine and a reference drug mustophoran (Les Labolatories Servier, France) was carried out in B6D2F1 mice. Ormustine was administered intravenously at a single dose of 50-135 mg/kg. Mustophoran was administered intravenously at a dose of 32 mg/kg twice (on days 2 and 9) and 3 times at a dose of 25 mg/kg (on days 2, 6 and 9). The follow-up period lasted till the death of animals. The antitumor effect of agents was assessed by the tumor growth inhibition and increase in life span of experimental mice compared to control animals. Results. It has been defined that the single intravenous dose of ormustine (125 mg/kg) is therapeutic for mice bearing melanoma B16 and epidermoid Lewis lung carcinoma. Conclusions. Ormustine possesses high antitumor effect against solid transplantable murine tumors. Ormustine is not inferior to mustophoran in the therapeutic effect against melanoma B16.