 Inclusion Criteria: - Diagnosed with knee OA as determined by American College of Rheumatology ACR criteria - Pain defined by a level of greater than 30 mm on a 100 mm Visual Analogue Scale VAS - No evidence of active effusion or inflammatory flare, confirmed by investigator - Must exhibit radiographic evidence of tibio-femoral compartment knee OA within 12 months of screening - Stable doses of any non-prescribed supplements e.g. glucosamine or chondroitin sulphate, shark cartilage, diacerhein, soya extract for at least 2 months prior to screening - Unchanged use of physical therapy, biomechanical devices or orthotic support within at least 2 months of screening - Subjects on nonsteroidal anti-inflammatory drug NSAID therapy must discontinue NSAIDs 3 days prior to baseline Day 1 - Before any study-specific procedure is performed, the appropriate written informed consent for participation in the study must be obtained Exclusion Criteria: - Malignancy within the previous 5 years, except for basal cell or in situ cancer - Significant hematologic disease - Active infection or history of recurrent or chronic infections - Known diagnosis of HIV, hepatitis B, or hepatitis C infection - Uncontrolled diabetes or cardiovascular disease and hypertension - Inflammatory arthropathy including secondary OA - Isolated OA of the patellofemoral joint bi or tri-compartmental involvement are not exclusions - End-stage bone-on-bone OA Kellgren Lawrence score of 4 - OA of the hip ipsilateral to the index knee - Total white cell count less than 2.0 x 109L andor platelet count less than 100 x 109L observed within 1 month preceding screening - Prior IA injection of anakinra or experimental interleukin-1 IL-1 inhibitor therapy - Concurrent treatment with subcutaneous SC anakinra - Concurrent or recent less than or equal to 1 month use of experimental therapy - Prior IA corticosteroid injection within 1 month of study - Prior viscosupplement therapy within 3 months of study - Contraindications to IA injections - Subjects who are pregnant or breast-feeding, or plan to become pregnant during the study - Subject is not using adequate contraception - Known allergy to E coli-derived products - Unable to understand informed consent - Concerns regarding subjects compliance with the protocol procedures - Subject will not be available for follow-up assessment - Active substance abuse 