Development of XL999 was stopped due to cardiac toxicities in the subjects

This clinical study is being conducted at multiple sites to determine the activity, safety, and tolerability of XL999 when given weekly to patients with metastatic clear cell renal cell carcinoma (RCC). XL999 is a small molecule inhibitor of multiple kinases including VEGFR, PDGFR, FGFR, FLT-3, and Src, which are involved in tumor cell growth, formation of new blood vessels (angiogenesis), and metastasis.

Inclusion Criteria:

• Males and females with histologically confirmed metastatic clear cell RCC
• Measurable disease according to Response Criteria for Solid Tumors (RECIST)
• No prior systemic cytotoxic chemotherapy
• Subjects who have received either no prior therapy for RCC, systemic immunotherapy only (such as interleukin-2 or interferon), or one agent targeting VEGF or a VEGFR (eg, bevacizumab, sorafenib, or sunitinib malate) may be enrolled
• ECOG performance status of 0 or 1
• Life expectancy ≥3 months
• Adequate organ and marrow function
• No other malignancies within 5 years
• Signed informed consent

Exclusion Criteria:

• Radiation to ≥25% of bone marrow within 30 days of XL999 treatment
• Subjects who have received systemic anticancer therapy within 30 days of XL999 treatment
• Subjects who have not recovered to grade ≤1 or to within 10% of baseline from adverse events due to medications administered >30 days prior to study enrollment
• History of or known brain metastases, current spinal cord compression or carcinomatous meningitis
• Uncontrolled and/or intercurrent illness
• Pregnant or breastfeeding females
• Known HIV