This is an open label, dose escalation study of ARQ 171 administered via intravenous infusion (IVI) into a peripheral vein weekly.

Patients with advanced solid tumors, who are refractory to available therapy or for whom no standard systemic therapy exists, will be enrolled.

Inclusion Criteria:

• Signed written informed consent must be obtained and documented prior to study-specific screening procedures.
• A histologically or cytologically confirmed advanced solid tumor
• ≥ 18 years of age
• Measurable disease as defined by Response Evaluation Criteria in Solid Tumors
• Karnofsky performance status ≥ 70%
• Male or female patients of child-producing potential must agree to use contraception or avoidance of pregnancy measures during the study and for 30 days after participation.
• Females of childbearing potential must have a negative serum pregnancy test.
• Laboratory results must meet study criteria.

Exclusion Criteria:

• Anti-cancer chemotherapy, radiotherapy, immunotherapy, or investigational agents within four weeks of first infusion
• Surgery within 4 weeks prior to first infusion
• Known untreated brain metastases
• Pregnant or breastfeeding
• Uncontrolled intercurrent illness, or uncontrolled infection or psychiatric illness/social situations that would limit compliance with study requirements
• Other cancer within the last five years, with the exception of adequately treated cone-biopsied in situ carcinoma of the cervix uteri or basal or squamous cell carcinoma of the skin