New steroidal alkylating agents in advanced stage D carcinoma of the prostate

In a previous study, 50 patients with prostatic carcinoma were given continuous oral estramustine phosphate at a dose of 15 mg/kg/day. All patients had progressed on prior standard treatment. The objective and subjective response rates were 19% and 36% respectively. Seven of the 50 patients are still receiving treatment after 1-3 years. One patient who was given estramustine phosphate therapy for 1 year achieved a complete response, which included disappearance of osteoblastic metastasis. He still continues in unmaintained remission despite the fact that estramustine phosphate therapy was stopped because of gastrointestinal toxicity. No serious side effects related to the drug have been seen. Estramustine phosphate may be given safely for a prolonged period and has a place in the treatment of advanced prostatic cancer refractory to hormonal therapy. Twenty-one patients with stage D prostatic adenocarcinoma who failed hormonal therapy were treated with a combination of estramustine phosphate (600 mg/m2/day) plus prednimustine (Leo-1031) (15 mg/m2/day) in daily oral doses. Fifteen patients have been treated with prednimustine alone. The preliminary results of the combination therapy (after 2-9 months) are as follows: five patients (24%) had an objective response and nine patients (44%) had subjective improvement. Only five (24%) did not benefit from the drug and seven (33%) are stable. Of the 16 patients treated with prednimustine alone, one patient has had an unequivocal objective response and one experienced a considerable objective improvement. These preliminary results indicate the possible advantage of adding an alkylating agent (prednimustine) to estramustine phosphate in advanced prostatic carcinoma.