Suramin in combination with mitomycin C in hormone-resistant prostate cancer. A phase II clinical study.

BACKGROUND

Hormone-resistant prostate cancer can respond to mitomycin C or to suramin. This trial was undertaken to investigate the value of mitomycin C given with low dose suramin.

PATIENTS AND

METHODS

Thirty-two patients with hormone-refractory prostate cancer were given suramin 350 mg/m2 daily for 5 days, followed by 350 mg/m2 weekly starting on day 14. Mitomycin C 12 mg/m2 was given every 5 weeks starting on day 14.

RESULTS

Toxicity included maculo-papular skin rash in 8 patients, haematological toxicity in 16 (anaemia 13, leucopenia 11 and thrombocytopenia 9, bleeding 8), infection in 4 and fatigue in 11. Ten patients developed neurotoxicity, (temporary sensory peripheral neuropathy in 8, upper limb motor neuropathy in 1, and restless legs syndrome in 1) and 9 developed proteinuria. Other toxicities were mild nausea and vomiting, oedema, transient elevation of liver enzymes, stomatitis, upper gastrointestinal symptoms, and alopecia. During induction treatment the median trough suramin level was 140 micrograms/ml (range 100-273) and during maintenance treatment the median suramin level was 93 micrograms/ml. The median overall trough level was 93 micrograms/ml. There were one complete and 6 partial responses. Fifteen patients had disease stabilization. The median time to treatment failure was 103 days, and the median survival 209 days.

CONCLUSION

The combination of suramin and mitomycin C has therapeutic activity, but causes significant toxicity in patients with hormone-resistant prostatic carcinoma.