This study evaluates a novel agent, SB-061, for the treatment of osteoarthritis of the knee. Half of the patients will receive the agent via intra-articular injection and half will receive a placebo injection.

The treatment of pain associated with osteoarthritis may include periodic intra-articular injections of corticosteroids or viscosupplements such as hyaluronic acid. SB-061 is anticipated to relieve osteoarthritis pain by reinforcing the cartilage matrix and providing a lubricating coating of the cartilage. Subjects will receive 2 intra-articular injections of either SB-061 or placebo and be followed for 3 months to evaluate pain amelioration. Subjects and Investigators are blinded to treatment allocation.

Inclusion Criteria:

• Femorotibial osteoarthritis of the knee
• Radiological OA Kellgren-Lawrence grade 2 or 3
• WOMAC Pain 1 score of the target knee of ≥4 and ≤ 9

Exclusion Criteria:

• Hypersensitivity to medications or to intra-articular injections
• Intra-articular delivery of corticosteroids or hyaluronic acid in the target knee within 6 months of study
• High dose systemic corticosteroid treatment of longer (>14 days) duration w/in 6 months of study
• Major surgery or arthroscopy of the target knee within year prior to study
• Planned surgery in the target knee within the next 3 months
• Concomitant inflammatory disease affecting either knee