Inclusion Criteria:

• Age ≥18 years
• Histologically confirmed, advanced or metastatic RCC with predominantly clear cell histology that is unresectable or medically inoperable.
• Experienced and failed at least one regimen of systemic therapy for RCC with CT documentation of disease progression.
• A previous CT (4 weeks or more prior to the Screening CT) showing progression of the target tumor(s) compared to a prior CT no more than 9 months previously
• At least one target tumor lesion is measurable at Screening with CT scan, according to RECIST, and not previously irradiated
• Karnofsky performance status of ≥70 (ECOG <2)
• Able to understand and sign an informed consent

Exclusion Criteria:

• Significant sarcomatoid, spindle cell, or nuclear grade 4 histology
• Significant non-clear cell RCC (for example, papillary, chromophobe, collecting duct, granular, or unclassified RCC)
• Total bilirubin >1.5 mg/dL
• Serum creatinine >2.0 mg/dL
• Hemoglobin <10.0 g/dL
• Absolute neutrophil count <2000/mm3
• Lymphocytes <800/mm3
• Platelet count <100,000/mm3
• AST (SGOT) or ALT (SGPT) ≥2.5 x institutional upper limit of normal
• Serum calcium >11.5 mg/dl
• International Normalized Ratio of Prothrombin Time (INR) >1.2
• FEV1 <60% predicted or FVC <60% predicted by spirometry (both are to be measured)
• Existing or history of brain metastases
• History of allergic reactions to compounds of similar chemical or biologic composition to the Study Agent rhLF
• Active ischemic heart disease, symptomatic congestive heart failure
• Serious active infection
• Psychiatric illness/social situations that would limit compliance with study requirements
• Autoimmune diseases (e.g., systemic lupus erythematosus, multiple sclerosis or ankylosing spondylitis)
• Other malignancies, except non-melanoma skin cancer, within 5 years of study entry
• Radiotherapy within 4 weeks prior to study treatment start
• Corticosteroid therapy within 4 weeks prior to treatment start, with the exception of inhaled or topical steroids
• Chemotherapy/Immunotherapy (e.g., IL-2, INFα, tumor vaccine) within 4 weeks prior to study treatment start
• Known HIV positive
• Receipt of any investigational medication within 30 days prior to participation in the study
• Pregnant or lactating patients, or fertile female patients with a positive pregnancy test (serum β-human chorionic gonadotropin [β-HCG] at Screening and on Day 1 prior to the first dose), or fertile female patients unwilling to use adequate contraception prior to study entry, during treatment and 30 days after completion of treatment
• Sexually active male patients unwilling to practice contraception while participating on this study and up to 30 days after completion of treatment
• Unable to take liquid medication by mouth or feeding tube