Study to Evaluate the Efficacy and Safety of FX006 in Patients With Hip Osteoarthritis

This is a two-part, multi-center, randomized, double-blind, placebo-controlled, parallel-group study in patients with hip OA. Approximately 70 patients will be enrolled in Part I and approximately 440 patients will be enrolled in Part II of the study. In each part, patients will be randomized to one of two treatment groups (1:1) and treated with a single IA injection of either 32 mg FX006 or normal saline.

This is a two-part, multi-center, randomized, double-blind, placebo-controlled, parallel-group study in patients with hip OA. Approximately 70 patients will be enrolled in Part I and approximately 440 patients will be enrolled in Part II of the study. In each part, patients will be randomized to one of two treatment groups (1:1) and treated with a single IA injection of either 32 mg FX006 or normal saline.

FX006 or saline placebo will be administered as a single IA injection with a 12-week follow-up period in the double-blind phase.

Patients participating in Part I of the study will be treated with a single IA injection of either 32 mg FX006 or normal saline and will return for follow up visits at Weeks 12, 16, 20, and 24. The patients will be discontinued at the time of notification by the Investigator.

Patients participating in Part II of the study will be treated with a single IA injection of either 32 mg FX006 or normal saline and will return for follow up visits at Weeks 12, 16, 20, and 24.

Patients participating in Part II of the study that are not clinically indicated for a second injection at Week 12 will return to the clinic at Weeks 16, 20, and 24 and will receive an open-label injection of FX006 at the first evaluation where the patient has been determined to meet all criteria. Patients will then return for follow-up visits every 4 weeks for 12 weeks post second injection and will complete the study 12 weeks post second injection (e.g., Week 24, 28, 32, or 36 depending on when the patient receives the open-label injection).

Patients participating in Part II of the study who are not eligible for a second injection after evaluation at Weeks 12, 16, 20, and 24 will complete the study at the Week 24 visit and complete the End of Study (EOS) assessments.

Eligibility Criteria:
Inclusion Criteria:

* Willingness and ability to comply with the study procedures and visit schedules and ability to follow verbal and written instructions
* Patients 40 to 80 years of age, inclusive, on the day of randomization (Day 1)
* Body Mass Index (BMI) ≤ 40 kg/m2
* Symptoms associated with OA of the index hip for ≥ 3 months prior to Screening visit
* Currently meet the American College of Radiology (ACR) Criteria (clinical and radiological) for OA of the index hip
* Kellgren-Lawrence (KL) Grade 2 or 3 in the index hip as confirmed by X-ray during Screening visit (centrally read)
* Qualifying mean score on the WOMAC A and C (0-10 NRS scale)
* Agree to maintain the similar activity level throughout the study
* Willingness to abstain from use of restricted medications

Exclusion Criteria:

* Patients who cannot washout of prohibited medications
* Diagnosed as secondary OA in the index hip including but not limited to articular fracture, major dysplasia or congenital abnormality, osteochondritis dissecans, acromegaly, ochronosis, hemochromatosis, Wilson's disease, or primary osteochondromatosis, etc.
* Ipsilateral chronic knee pain
* Sciatica
* Atrophic osteoarthritis, femoral head necrosis and/or collapse, or subchondral bone insufficiency fracture in the index hip joint determined via central reading
* Current or history of infection in the index hip (e.g. osteomyelitis) or current skin infection at injection site
* Trauma or surgeries (e.g., arthroscopy, knee surgery) of lower limbs within 52 weeks with sequelae, etc.
* History or current evidence of reactive arthritis, rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, or arthritis associated with inflammatory bowel disease, systemic lupus erythematosus or other autoimmune diseases
* Any planned surgeries in the lower limbs during the study period, or any other surgery during the study period that would require use of a restricted medication
* Presence of surgical hardware or other foreign body in the index hip
* Planned/anticipated surgery of the index hip or any other surgery that would require use of a restricted medication during the study period
* IA corticosteroid of any joint within 3 months of Screening visit (investigational or marketed, including FX006)
* IA treatment of index hip with any of the following agents within 6 months of Screening: any biologic agent or hyaluronic acid (investigational or marketed)
* IV or IM corticosteroids (investigational or marketed) within 3 months of Screening
* Oral corticosteroids (investigational or marketed) within 1 month of Screening
* Inhaled, intranasal or topical corticosteroids (investigational or marketed) within 2 weeks of Screening visit
* Planned or expected changes to lifestyle with regard to physical activity, physical therapy, acupuncture, transcutaneous electrical nerve stimulation (TENS), or bracing within 1 month prior to Screening and changes throughout the duration of the study
* Women of child-bearing potential (not surgically sterile or post-menopausal for at least 1 year as documented in medical history) not using a highly effective method or who are pregnant or nursing