The objective of this study is to evaluate the safety of an injection of Cingal® in subjects with Osteoarthritis (OA) of the knee who participated in Cingal 13-01, and who received either a Cingal, Monovisc, or saline injection in the 13-01 study. The safety evaluation will be done by a through examination of the incidence of adverse events and physical examination of the knee.

The Cingal 13-02 study is a follow-on study to the recently completed clinical trial Cingal 13-01 [NCT01891396]. Cingal 13-01 was a multi-center, randomized, double-blind, Phase III study that enrolled 368 subjects at up to 20 sites in Canada and Europe. The Cingal 13-01 study objective was to assess the safety and effectiveness of a single injection of Cingal® for relief of joint pain and symptoms in patients with osteoarthritis (OA) of the knee. The study had three arms: the Cingal® investigational arm, an active comparator arm (Monovisc®) and a control arm (saline). Cingal 13-02 is designed to evaluate the safety of an open-label injection of Cingal® in subjects who received a study injection in the Cingal 13-01 trial. Sites that enrolled 5 or more subjects in the Cingal 13-01 study were eligible to participate in the Cingal 13-02 study. All subjects at these sites who met enrollment criteria had the option to participate in the follow-on study.

Inclusion Criteria:

1. Subject completed Cingal 13-01 and is interested in participating in the follow-on study
2. Subject must be willing to abstain from other intra-articular or surgical treatments of the index knee for the duration of the study
3. Subject is willing to discontinue all analgesics except acetaminophen/paracetamol for the duration of the study
4. Subject is willing to use only acetaminophen/paracetamol (up to a maximum of 4.0 grams per day per the package insert) for the treatment of joint pain for the duration of the study. At least twenty-four hours prior to the injection and each follow-up visit, the subject is willing to discontinue use of acetaminophen/paracetamol
5. Subject is able to understand and comply with the requirements of the study and voluntarily provides consent

Exclusion Criteria:

1. Subject received an intra-articular injection or underwent a surgical procedure of the index knee since the study injection in Cingal 13-01
2. Subject is taking medication at the time of consent which could interfere with the treatment procedure, healing and/or assessments. This includes but is not limited to oral or injectable anticoagulant treatments, anti-aggregant platelet treatment and opioid analgesics. Low dose aspirin used for cardiovascular protection is allowed if a stable regimen is maintained for the duration of the study.
3. Subjects who had an oral, intramuscular, intravenous, rectal suppository or topical (excluded in index knee only) corticosteroid within 30 days of signing the ICF are excluded. Topical corticosteroid use at any site other than the index knee is allowed.
4. Subject has a contraindication to IA injections, aspiration of the index knee, corticosteroids, hyaluronan, or acetaminophen/paracetamol.
5. Subject is pregnant or breastfeeding or a woman of child bearing potential who refuses to use effective contraception during the course of the study.
6. Subject participated in a research study other than Cingal 13-01 within 60 days of consent.

There is not a plan to share individual participant data

Analysis population is the Safety Population and consists of all 242 enrolled subjects

Adverse events were collected in Cingal 13-02 within the first six weeks after injection.

The definitions of adverse events and serious adverse events is the same as used in the clinicaltrials.gov definitions. The incidence, timing, severity, and relationship to treatment of all Adverse Events (AE) were collected and coded using Medical Dictionary for Regulatory Activities (MedDRA).

Cingal 13-02 is a follow-on safety trial to Cingal 13-01 and collected safety data only from an open-label injection of Cingal.

Cingal 13-02 was an open label follow-up study. The participants, investigators and outcomes assessors were blinded to the specific study injection subjects had previously received in Cingal 13-01.