Study to Compare Exposure of TA Following Administration of Either FX006 or TAcs in Patients With Bilateral Knee OA

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.

Eligibility Criteria:
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