Safety and Activity of G-202 in Patients With Clear Cell Renal Cell Carcinoma That Expresses PSMA

Inclusion Criteria: * Male or female patients age ≥ 18 years * Pathologic documentation of clear cell renal cell carcinoma * Disease that is resistant or refractory to standard of care * ECOG Performance Status \< 2 * Most recent tissue biopsy demonstrates PSMA expression by immunohistochemical staining * Adequate bone marrow function measured within 7 days prior to first infusion of G-202 (absolute peripheral granulocyte count \> 1500 cells/m3; platelet count \> 100,000 cells/m3) * Adequate hepatic function measured within 7 days prior to first infusion of G-202 (Albumin ≥ 2.8 g/dL; AST and ALT ≤ 5 x ULN; Total bilirubin \<2 mg/dL) * Adequate renal function measured within 7 days prior to first infusion of G-202 (Proteinuria level ≤ 2 by urine dipstick; Serum creatinine ≤1.5 x ULN) * Normal coagulation profile measured within 14 days prior to first infusion of G-202 (INR ≤ 2.3; aPTT ≤ 1.5 X ULN) * No history of substantial non-iatrogenic bleeding diatheses. Use of anti-coagulants is limited to local use only (for control of central line patency) * Patients must sign an informed consent indicating that they are aware of the investigational nature of the study and are willing to participate in the study * Females of child-bearing potential and males with female partners of child-bearing potential must be willing to use acceptable methods of contraception to avoid pregnancy (for example, oral, injectable, or implantable hormonal contraceptive; tubal ligation; intra-uterine device; barrier contraceptive with spermicide; or vasectomized partner) beginning before the first infusion of G-202 and for 3 months after the last infusion of G-202 Exclusion Criteria: * Uncontrolled cardiac, hepatic, renal, or neurologic/psychiatric disorder * HIV positivity or history of chronic hepatitis B or C infection * Congestive heart failure New York Heart Association (NYHA) class 3 or 4, or history of congestive heart failure New York Heart Association (NYHA) class 3 or 4, unless a 2D echocardiogram or multi-gated acquisition scan (MUGA) performed within 3 months of enrollment demonstrates a left ventricular ejection fraction \>45% * History of another malignancy within the previous 5 years other than curatively treated non-melanoma skin cancer or or intraepithelial carcinoma of the cervix * Surgical resection or major surgery within 4 weeks or stereotactic biopsy within 1 week of first G-202 treatment * Treatment, chemotherapy, radiation therapy, immunotherapy, or investigational drug for the patient's renal cell cancer within 28 days prior to first infusion of G-202 * Currently requiring systemic administration of antibiotics or chronic administration of anti-viral agents * Use of anti-coagulants is limited to local use for control of central line patency * History or evidence of cardiac risk, including corrected QT interval on screening ECG \> 470 msec, clinically significant uncontrolled arrhythmias or arrhythmia requiring treatment with the exceptions of atrial fibrillation and paroxysmal supraventricular tachycardia, history of acute coronary syndromes within 6 months prior to the first dose of study therapy (including myocardial infarction and unstable angina, coronary artery bypass graft, angioplasty, or stenting), any history of congestive heart failure with most recent ejection fraction \< 45% * Uncontrolled cardiac or coronary artery disease * Uncontrolled hypertension (mean systolic BP ≥ 160 mm Hg and/or mean diastolic BP ≥ 100 mm Hg on 3 determinations 5 minutes apart while on 2 anti-hypertensive agents) or hypertension requiring treatment with more than 2 anti-hypertensive agents. * Severe or uncontrolled medical disease, including uncontrolled diabetes, congestive heart failure, chronic renal disease or chronic pulmonary disease * Severe gastrointestinal bleeding within 12 weeks of treatment with G-202 * Requirement for chronic use of medications known to be strong inhibitors or inducers of cytochrome (CYP3A4) iso-enzymes (Appendix 3) Note: If patients can stop receiving these medications, CYP3A4 inhibitors should be discontinued at least 7 days prior to starting treatment with G-202 * Known hypersensitivity to any study drug component including thapsigargin derivatives, polysorbate 20, or propylene glycol * Any other condition, including concurrent medical condition, social circumstance or drug dependency, which in the opinion of the investigator could compromise patient safety and/or compliance with study requirements