The purpose of this study is to evaluate the safety and tolerability of extended treatment with FK228 in patients with metastatic renal cell carcinoma or hormone refractory prostate cancer who have at least demonstrated stable disease on prior Fujisawa sponsored FK228 clinical trials.

This is a Phase II, non-randomized, open-label, single arm, continuation trial.

Inclusion Criteria:

• Patient has completed 6 cycles of therapy in a prior Fujisawa-sponsored FK228 clinical trial;
• Patient has immediate past participation (not to exceed 21 days from Day 15 of cycle 6 in the previous study) in a prior Fujisawa-sponsored FK228 clinical trial;
• Patient has demonstrated stable disease, partial response or complete response as best overall response in their prior Fujisawa-sponsored FK228 clinical trial.

Exclusion Criteria:

• Patient has been on a prior Fujisawa-sponsored FK228 clinical trial, left the trial and then received alternative anti-neoplastic therapy