An Study to Evaluate Safety and Tolerability of OA-SYS in Subjects With Moderate to Severe Osteoarthritis of the Knee Joint

Inclusion Criteria: * Adults between the ages of 35 - 75 years Body Mass Index (BMI) less than 39 kg/m2 * 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 treatments from Screening through End-of-Treatment * Kellgren-Lawrence grading scale score of 3 or 4 for OA of the knee * No clinically significant abnormalities observed in medical history, physical exam vital signs, and laboratory assessments * For females of reproductive potential: use of effective contraception for at least 1 month prior to screening and agreement to use such a method till end of the study period and negative pregnancy test * For males of reproductive potential: use of condoms and other methods to ensure effective contraception Exclusion Criteria: * Known or suspected infection of the target joint * Subjects with surgery for OA in the target joint * Subject with reactive arthritis, rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, or arthritis associated with inflammatory bowel disease * Subject with myocardial infarction, congestive heart failure, and other severe heart disease or hypertension (or medical history of hypertension) that are not controlled below 140/90 mmHg even with treatment with more than three antihypertensive drugs * Subject with serious medical conditions other than cardiovascular disease * Subject with, or with a medical history of autoimmune diseases * Subject with an infection that requires parenteral antibiotic administration within 30 days prior to screening * Subject with a medical history of mental disorder or epilepsy * Subject abuse alcohol 10 times a week or smoke 25 cigarettes a day * Subject who was diagnosed with cancer within 5 years before screening * Subject who participated in another clinical trial within 6 months prior to the screening of this clinical trial * Subject who was administered with immunosuppressants such as cyclosporin A or azathioprine within 6 weeks prior to the screening * Subject who had intra-articular administration such as sodium hyaluronate injections within 6 months prior to the screening * Clinical findings consistent with active infection or crystal disease in the index joint within 1 month prior to the screening * History of fracture in the index limb or fracture with sequelae within 12 months prior to the screening * Joint instability or history of acute dislocation within 12 months prior to the screening * Planned or anticipated surgery of the joint during the study period * Presence of surgical hardware or other foreign body in the index joint * Surgery or arthroscopy of the index joint within 12 months of screening * Intra-articular treatment of any joint with any of the following agents within 6 months prior to the screening: Any corticosteroid preparation (investigational or marketed), any biologic agent (e.g., platelet rich plasma (PRP) injection, stem cells, prolotherapy, amniotic fluid injection) * Treatment of the index joint with any investigational therapy within 6 months prior to the screening * Serious life-threatening conditions * Allergies to anesthesia * Subject who is breastfeeding.