This study will evaluate dosing regimens of 4975 in terms of safety and tolerability when delivered as an intra-articular injection in the knee. Secondary objectives will be to explore the efficacy of 4975 in terms of onset, extent and duration of pain relief.

This is a single site study. The study drug, 4975, will be administered in various dosing regimens by intra-articular injection followed by an observation period of up to 12 weeks. Pain in the treated knee will be assessed before, during and after administration of the study drug.

Inclusion Criteria:

• Male or female patients aged 40 years or over.
• Body mass index (BMI) of 35 or less.
• History of OA of the knee for at least 1 year and has experienced pain in the target area for at least six months.
• X-Ray of the target knee.
• Willing and able to complete the study procedures.

Exclusion Criteria:

• Female patients who are pregnant or lactating or who plan to get pregnant.
• Clinically significant form of joint disease other than OA.
• Medical condition that could adversely impact the patient's participation, safety or affect the conduct of the study.
• Prior major trauma in the target knee or major surgeries such as partial or total knee arthroplasty.
• Arthroscopic surgery on the target knee within 6 months.