Safety Study of GC1008 in Patients With Focal Segmental Glomerulosclerosis (FSGS) of Single Doses of GC1008 in Patients With Treatment Resistant Idiopathic FSGS

Inclusion Criteria: * GFR≥25ml/min/1.73m2 calculated by the MDRD equation * Urinary total protein: creatinine ratios \>200mg/mmol derived from the average of 2 first morning voids taken during screening period * Biopsy confirmed as idiopathic FSGS by a central reviewer * Treatment resistance. NOTE:Patients to have received minimum 6 week course of steroids or immunosuppressant * If receiving treatment with an ACEi and/or ARB dose to be stable for a minimum of 4 weeks prior to randomization * Influenza vaccine (according to season) * Negative screening per American Cancer Society (ACS) 2003 guidelines, as appropriate to patient demographics and clinical status Exclusion Criteria: * Secondary FSGS * steroid resistant patients who are unable to reduce their steroid dose to \<10mg/day of prednisolone or equivalent 4 weeks prior to study dosing day * Positive serology for serious infections (including but not limited to infection with Hep B or C, HIV) * Concomitant illnesses:Diabetes Type I; Cardiac or Hepatic disease, HIV; Cancer, precancerous state (eg familial adenomatous polyposis; Any condition requiring treatment with other immunosuppressant drugs within 4 weeks prior to dosing day or during the course of the study * Pre-existing oral-pharyngeal disease (dental carries and other minor dental disease are acceptable) * Haemoglobin level of \<9.0g/dL prior to dosing * Treatment with coumadin, anti-vitamin K analogues or low molecular weight heparins. Patients must have stopped treatment a minimum of four weeks prior to receiving study medication. * Patients requiring ongoing treatment with non-steroidal anti-inflammatory drugs (NSAIDs). Patients must have stopped treatment a minimum of four weeks prior to receiving study medication. * Patients who have had surgery/fracture within 3 months prior to dosing day * History of cancer unresolved within 5 years prior to screening or a known precancerous state; or any form of skin cancer either current or past history * Women who are pregnant, lactating or who plan to become pregnant within 4 months of infusion * Women of childbearing potential unless taking medically acceptable contraceptive * Men with female partners of childbearing potential unless they are taking medically acceptable contraceptive precautions * Use of any investigation drug administered as part of a clinical trial within 4 weeks prior to commencing screening * Other clinically significant, uncontrolled medical condition that in the investigator's opinion may interfere with the assessment or follow-up * Active ethanol or drug abuse, excluding tobacco use * Electrocardiogram (ECG) abnormalities considered to be clinically significant at screening * Unable to comply with the requirements of the study * Active thrombophlebitis, thromboembolism, hypercoagulability states, bleeding, or use of anticoagulation therapy (including anti-platelet agents). Patients with a history of deep venous thrombosis may participate if successfully treated, completely resolved, and no treatment has been given for \>4 months.