The purpose of this study was to evaluate the safety, pharmacokinetics and pharmacodynamics of FX006 in patients with osteoarthritis of the knee.

This study was a double-blind, randomized, parallel-group, active comparator design. The study was conducted in male and female patients ≥35 years of age with symptomatic OA of the knee.

Twenty-four (24) patients with knee OA were randomized (1:1:1:1) and treated with a single IA injection of either 10, 40, or 60 mg of FX006 or 40 mg of TCA IR.

Each patient was evaluated for a total of 6 weeks following a single IA injection. Following screening, safety, PK and pharmacodynamics (PD) were evaluated during one (1) 48-hour in-patient period (Day -1 to Day 2), two (2) 24-hour in-patient periods (Day 14-15 and Day 42-43) and seven (7) out-patient visits (Days 3, 4, 5, 8, 22, 29 and 36).

Main Inclusion Criteria:

• Willingness and ability to comply with the study procedures and visit schedules and ability to follow verbal and written instructions
• Male or female >=35 years of age
• Diagnosis of unilateral or bilateral OA of the knee for at least 6 months prior to Screening with confirmation of OA according to American College of Rheumatology Criteria for Classification of Idiopathic OA of the Knee (clinical and radiological) based on an X-ray performed within 6 months prior to Screening or during the Screening period
• Body mass index (BMI) ≤ 40 kg/m2
• Willingness to abstain from use of the protocol-specified restricted medications

Main Exclusion Criteria:

• History of Reiter's syndrome, rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, arthritis associated with inflammatory bowel disease, sarcoidosis or amyloidosis
• History of arthritides due to crystals (e.g., gout, pseudogout)
• History of infection in the index joint
• Clinical signs and symptoms of active knee infection or crystal disease of the index knee
• Presence of surgical hardware or other foreign body in the index knee
• Unstable joint (such as a torn anterior cruciate ligament)
• IA corticosteroid (investigational or marketed) in any joint within 3 months of Screening
• IA hyaluronic acid (investigational or marketed) in the index knee within 6 months of Screening
• Oral, inhaled or intranasal corticosteroids (investigational or marketed) within 1 month of Screening
• Prior arthroscopic or open surgery of the index knee within 12 months of Screening
• Planned/anticipated surgery of the index knee during the study period
• History of or active malignancy, with the exception of resected basal cell carcinoma, squamous cell carcinoma of the skin, or resected cervical atypia or carcinoma in situ within 5 years
• Insulin-dependent diabetes
• History of or active Cushing's syndrome
• Any other clinically significant acute or chronic medical conditions (e.g., uncontrolled diabetes)
• Skin breakdown at the knee where the injection would take place
• Women of child-bearing potential not using effective contraception or who are pregnant or nursing

Adverse Events were collected from post injection on Day 1 through Day 43.