The purpose of this study is to evaluate the activity of FK228 in metastatic renal cell carcinoma (RCC) patients who have developed progressive disease (PD) following or during treatment with immunotherapy.

Inclusion Criteria:

Patients must fulfill all of the following criteria to be eligible for study participation:

• Age ≥ 18 years;
• Histologically confirmed Renal Cell Carcinoma (RCC);
• Metastatic disease, with measurable lesions according to the Response Evaluation Criteria in Solid Tumors (RECIST);
• Failure of prior cytokine therapy;
• Documented progressive disease;

Exclusion Criteria:

Patients are ineligible for entry if any of the following criteria are met:

• Significant cardiac disease including congestive heart failure, history of myocardial infarction within one year, uncontrolled dysrhythmias, or poorly controlled angina
• History of serious ventricular arrhythmia
• Corrected QT interval (QTc) ≥ 500 msec
• Known infection with Human Immunodeficiency Virus (HIV), Hepatitis B, or Hepatitis C;
• Previous extensive radiotherapy involving ≥ 30% of bone marrow
• Coexistent second malignancy or history of prior malignancy within previous 5 years