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.