Objective: Bropirimine is an oral immunostimulant found to have efficacy in human transitional cell carcinoma in situ following the initial discovery of its antitumor activity against the murine bladder cancer MBT-2. To determine if bropirimine might have activity in prostate cancer, it was tested against two rodent prostate cancer cell lines in vivo.
Methods: Tumors resulted from subcutaneous injection of PAIII and Dunning MAT-LyLu rodent prostate cancer cells. Bropirimine was given at 250 mg/kg orally on different schedules, and tumor volume and survival were recorded.
Result: In the PAIII model, bropirimine prevented growth when given the day of tumor injection, and 95% of advanced tumors regressed completely when start of therapy was delayed. Bropirimine also caused growth inhibition and prolongation of survival in the MAT-LyLu model.
Conclusions: Bropirimine immunotherapy is very effective in vivo against the PAIII cell line, and it has significant growth inhibition against the Dunning MAT-LyLu cell line.