A randomized, double-blind, placebo-controlled, multi-center, phase 3 study to determine the efficacy and safety of TG-C in subjects with Kellgren and Lawrence Grade 2 or 3 Osteoarthritis of the Knee, Osteoarthritis Research Society International (OARSI) medial joint space narrowing (JSN) Grade 1 or 2 of the knee joint. TG-C is to be administered by a single intra-articular injection to the damaged joint area via ultrasound guidance. Patients will be followed for 24 months for safety and efficacy.

This protocol is designed to assess the safety and efficacy of TG-C in treating symptoms of osteoarthritis of the knee and determining disease modifying effects of TG-C. This study is intended for the treatment of patients with K&L Grade 2 and 3 osteoarthritis and OARSI JSN Grade 1 and 2. Assessments will be made on both the symptomatic effects of pain (VAS), function (WOMAC), and Quality of Life (SF-12) as well as the physical effects (JSW, MRI evaluations of whole knee joint organ tissues and structure) and biochemical biomarkers. This is a placebo-controlled study, TG-C will be compared to normal saline as a control. Additionally, this protocol is designed to evaluate the safety of TG-C. Safety will be evaluated by observation of the injection site for irritation or other effects, the incidence and severity of adverse events, and changes in physical examination findings, radiographic criteria, and laboratory tests. Patients will be followed for 24 months for both safety and efficacy with annual cancer surveillance questionnaires through 15 years post dose for subjects who do not enroll in the Long Term Safety study.

Inclusion Criteria:

• Aged 40 or older
• BMI between 18.5 and 40
• KL Grade 2 or 3 knee OA
• OARSI Grade 1 or 2 medial JSN
• Pain >= 40 on VAS scale
• Written informed consent
• Using birth control

Exclusion Criteria:

• Knee symptoms that result in difficulty or inability to walk
• Knee effusion >2+
• Has Grade 3 OARSI JSN
• MRI exam indicates fracture or tumor
• Has a positive result on RCR testing at screening
• Has taken NSAIDS with 14 days of baseline
• Has taken steroidal anti-inflammatory or biologic therapy medication within 2 months of baseline
• Chronic (>21 days) narcotic use
• Recent history (within 1 year) of drug or alcohol abuse
• Pregnant or lactating
• Has received injection to target knee within 2 months prior to study entry
• History of various disorders of the knee including but not limited to rheumatoid arthritis, psoriatic arthritis, autoimmune disorder, chondrocalcinosis, gout, hemochromatosis, villonodular synovitis, or synovial chondromatosis
• Severe hip osteoarthritis ipsilateral to the target knee
• Ongoing infectious disease including but not limited to HIV, HTLV-1, VSV-G, HBV, or HCV.
• Clinically significant congestive heart failure, hepatic disease, kidney disease, adrenal insufficiency, acromegaly, uncontrolled hyper- or hypothyroidism, or non-specified uncontrolled endocrine disorder.
• Uncontrolled diabetes based on a HbA1c > 8% at screening.
• Documented active malignancy within the last 5 years except for basal cell carcinoma, squamous cell carcinoma, and benign pigmented nevi.

Double-blind