Placebo-controlled study on the efficacy of the pyrimido-pyrimidine derivative RA 233 in ovarian cancer.

This prospective double-blind, multicenter study was aimed at evaluating the clinical efficacy of RA 233 (a derivative of dipyridamole) in ovarian cancer. Following primary surgery, 497 patients with ovarian cancer were treated with combination cytotoxic chemotherapy; those in clinical stage II were also treated with pelvic irradiation. The patients were randomly allocated to receive RA 233 (N = 251) or placebo (N = 246) for 2 years. The groups did not significantly differ from each other in any of the clinical, therapeutic, or histopathological variables evaluated. There were no significant differences between RA 233-treated patients and placebo-treated patients with respect to appearance of new metastases, progressive growth of malignancy, or survival of all patients, in any of the clinical stages of the disease, in radically operated patients or in nonradically operated patients, in different histopathological groups, or in different age groups. Hence, supplementation of carcinoma therapy with long-term administration of the antiplatelet drug RA 233 has no clinical benefit in this malignancy. Using Cox's multifactorial stepwise analysis, this study revealed that the clinical stage of the disease, the extent of surgery, and the histopathology of the tumor, but not the age of the patient or the use of RA 233, were significant and independent predictors of survival. With respect to the histopathology, the poor prognosis of serous and mesonephric carcinomas appeared to be independent of the other prognosis indicators.