Evaluation of the antitumor activity of 2-[3-(2-chloroethyl)-3-nitrosoureido]-1,3-propanediol (chlonisol) in C57BL/6 mice with intracranially transplanted B16 melanoma

Background. The arsenal of antitumor drug therapy for melanoma brain metastases is limited. The search and study of new agents capable to penetrate the blood-brain barrier and provide a therapeutic effect against intracranial tumors remains an unmet clinical need. The aim is to evaluate the antitumor activity of the domestic derivative of nitrosoalkylureas, chlonisol, in mice with intracranially transplanted syngeneic B16 melanoma. Methods. The experiment was carried out in 18 female inbred C57BL/6 mice. After intracranial tumor transplantation, performed according to modified technique, the animals were randomized into two groups: I. Control (n = 10) – the animals were injected with normal saline 10 ml/kg intraperitoneally; II. Chlonisol (n = 8) – the animals were treated with the test compound at a dose of 15 mg/kg in normal saline intraperitoneally. The single administration of normal saline and chlonisol was performed 24 hours after tumor transplantation. The end point of the study was overall survival (OS) of the animals. Results. Compared with the control group, administration of chlonisol significantly increased the median OS of mice from 13 to 18 days (log rank test, p = 0.0005). Chlonisol significantly decreased the risk of death by 71 % compared with the control group (HR = 0.29; 95 %CI 0.10–0.82). By the 15th day after intracranial transplantation of B16 melanoma, all 10 mice in the control group died from intracerebral tumors (100 %), whereas in the chlonisol group only 2 out of 8 (25 %) mice died (Fisher's exact test, p = 0.0015). Conclusion. Despite the exploratory nature of the present study, it provides a good starting point for further research of chlonisol in brain tumors.

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