In this positive and negative controlled study, Proellex showed no microscopic evidence for tumor induction as compared to both controls. Proellex was tested at 10, 40 and 100 times the human dose in this well-recognized and -characterized study, said Repros. Previously, the company reported that the positive control, urethane, yielded easily identifiable tumors on gross necropsy while none were observed in the Proellex treated animals.
This mouse carcinogenicity study of Proellex was sponsored by Repros Therapeutics at BioReliance in Rockville, Maryland using a breed of mice bearing the rasH2 mutation. These rasH2 mice have been genetically manipulated making them primed for the development of tumors when treated with carcinogens.
Male and female animals had been treated with daily doses of Proellex for 26 weeks and an evaluation was made as to whether cancers developed over that period of time when compared to a control material. Gross examination revealed no apparent indication of a tumorigenic response.
All tissues were then assessed for microscopic evaluation. The assessment concluded that there were no treatment-induced hyperplastic or neoplastic changes in any of the Proellex treated groups. A final study report is in the process of being prepared for submission to the FDA.