This is a randomized, open-label, parallel group study to compare systemic exposure of triamcinolone acetonide following administration into both knees of either FX006 or TAcs.

This is a randomized, open label, parallel group study that will be conducted in male and female patients ≥ 40 years of age with bilateral knee OA.

Approximately 24 patients will be randomized to one of two treatment groups (1:1) and treated with IA injections to both knees of either:

• extended-release FX006 64 mg total dose (approximately 12 patients) or
• immediate-release TAcs 80 mg total dose (approximately 12 patients) Each patient will be screened to confirm the diagnosis of OA and eligibility based on the inclusion/exclusion requirements and will be randomized to treatment on Day 1. Following screening, pharmacokinetics (PK) and safety will be evaluated at 6 out-patient visits scheduled on Study Days 1 [calendar day of injection], 2, 8, 15, 29, and 43.

Inclusion Criteria:

• Written consent to participate in the study
• Male or female greater than or equal to 40 years of age
• Symptoms consistent with OA in both knees for greater than or equal to 6 months prior to Screening (patient reported is acceptable)
• Currently meets ACR Criteria (clinical and radiological) for OA in both knees
• Knee pain in both knees for greater than 15 days over the last month (as reported by the patient)
• Body mass index (BMI) less than or equal to 40 kg/m2
• Morning serum cortisol result within normal range at Screening (5-23 mcg/dL or 138-635 nmol/dL)
• Ambulatory and in good general health
• Willing and able to comply with the study procedures and visit schedules and able to follow verbal and written instructions.
• Willing to abstain from use of protocol-restricted medications during the study

Exclusion Criteria:

• Reactive arthritis, rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, or arthritis associated with inflammatory bowel disease
• History of infection in either knee joint
• Clinical signs and symptoms of active knee infection or crystal disease in either knee within 1 month of Screening
• Unstable joint (such as a torn anterior cruciate ligament) in either knee within 12 months of Screening
• Presence of surgical hardware or other foreign body in either knee
• Surgery or arthroscopy of either knee within 12 months of Screening
• IA treatment of any joint with any of the following agents within six (6) months of Screening: any corticosteroid preparation (investigational or marketed, including FX006), any biologic agent (e.g., platelet rich plasma (PRP) injection, stem cells, prolotherapy, amniotic fluid injection; investigational or marketed).
• IA treatment in either knee with hyaluronic acid (investigational or marketed) within 6 months of Screening
• Parenteral or oral corticosteroids (investigational or marketed) within 3 months of Screening
• Inhaled, intranasal or topical corticosteroids (investigational or marketed) within 2 weeks of Screening
• Females who are pregnant or nursing or plan to become pregnant during the study; men who plan to conceive during the study

Adverse Events were collected following IA administration through the final study visit at 43 days.