The purpose of this study is to assess the safety and tolerability of the multiple receptor tyrosine kinase (RTK) inhibitor (including EGFR, VEGFR2, ErbB2, and EphB4) XL647 when given orally daily to adults with advanced solid tumors.

Inclusion Criteria:

• Subject has histologically confirmed malignancy that is metastatic or unresectable
• Subject has disease that is assessable by tumor marker, physical, or radiologic means
• Subject is at least 18 years old
• Subject has an ECOG performance status ≤ 2 (Karnofsky ≥ 60%)
• Subject has a life expectancy ≥ 3 months
• Subject has normal organ and marrow function
• Subject gives written informed consent
• Subject must use an accepted method of contraception during the study
• Female subjects of childbearing potential must have a negative pregnancy test

Exclusion Criteria:

• Subject has received anticancer treatment within 30 days of first dose of XL647
• Subject has received another investigational agent within 30 days of first dose of XL647
• Subject has known brain metastases
• Subject has corrected QT interval (QTc) of > 0.45 seconds
• Subject is currently receiving anticoagulation therapy with warfarin
• Subject has uncontrolled intercurrent illness
• Subject is pregnant or breastfeeding
• Subject has known HIV