To evaluate the effectiveness of 4 g Swisse High Strength Deep Sea Krill Oil (Superba BOOST) daily on pain reduction in adults with mild to moderate osteoarthritis of the knee compared to placebo over a 6 month period.

This is a multicentre, randomised, double-blind, placebo-controlled parallel-arm study.

Applicants will be eligible to participate if they have mild to moderate OA of the knee. Diagnosis of OA of the knee will be made according to clinical diagnosis, using the American College of Rheumatology (ACR) Criteria for the classification of Idiopathic OA of the Knee and the Kellgren-Lawrence grading scale. In addition, eligible applicants will have been experiencing knee pain on at least 4 days per week, for at least 3 months and they will report knee pain between 4 and 8 cm (inclusive) on a visual analogue scale (VAS) for the 7 days prior to Day 1 of the trial (Baseline). Severity of OA of the knee will be assessed based on X-ray performed at the Screening Visit using the Kellgren-Lawrence (KL) radiographic criteria, and participants with severe radiographic knee OA (KL joint space narrowing (JSN) above grade 3) will be excluded.

Applicants will attend a screening visit following pre-screening assessments to assess their general health and eligibility for inclusion into the study.

On Day 1 eligible participants will be randomly allocated to receive one of two study treatments. Participants will take the assigned treatments daily for six months.

Participants will return to the clinic at 3 months and 6 months for study assessments. Participants will complete an online survey at 1, 2, 4 and 5 months to assess protocol compliance, adverse events and use of concomitant medications. Any queries from the survey will be followed up by phone call.

A final participant online survey and phone call (if needed) will be conducted 28 days after the 6 month visit for a final safety assessment.

Inclusion Criteria:

1. Male or Female aged 40 - 65 years, inclusive
2. Clinical Diagnosis of OA of the index knee according to the ACR Criteria for the classification of Idiopathic OA of the Knee
3. Kellgren-Lawrence (KL) grade 1-3 OA, evidenced by Knee X-ray performed during the screening period
4. Experiencing pain of the index knee on at least 4 days per week for the last 3 months (based on self-report)
5. Pain of the index knee between 4 and 8 cm (inclusive) as self-assessed on a visual analogue scale (VAS) over the 7 days prior to Day 1
6. Body mass index (BMI) >18.5 kg/m2 and <35 kg/m2 on Day 1
7. Willingness to abstain from use of restricted medications.
8. Habitual intake of long chain (LC) omega-3 polyunsaturated fatty acids (PUFA) (from food and supplements) <500mg/day as assessed using the Australian PUFA food frequency questionnaire (FFQ) during the screening period and willingness to maintain a low intake throughout the study. Higher intakes of LC omega-3 PUFA will require a 3 month washout period.
9. Willing to provide written Informed Consent.

Exclusion Criteria:

1. Severe radiographic knee OA in any knee defined as Kellgren-Lawrence (KL) score >3 based on X-ray (weight bearing) performed during the screening period.

2. Ipsilateral hip OA such that it would compromise assessment of knee pain.

3. Fibromyalgia, chronic pain syndrome or other concurrent medical or arthritic conditions which could interfere with the evaluation of the index knee.

4. History of Reiter's syndrome, rheumatoid arthritis (RA), psoriatic arthritis, ankylosing spondylitis, arthritis associated with inflammatory bowel disease, sarcoidosis or amyloidosis or any other forms of inflammatory arthritis (e.g. gout, pseudogout). Gout is excluded unless the participant is on preventative treatment and has not had an attack in the last 12 months.

5. History or clinical signs and symptoms of infection in the index joint in the last 5 years.

6. Knee pain that is not clinically attributable to OA of the knee (e.g., radicular low back pain and hip pain that is referred to the knee that could cause misclassification).

7. Pain in any other area of the lower extremities or back that is equal to or greater than the index knee pain (based on self-report).

8. Arthroscopy or open knee surgery in the index knee in the previous 12 months or planned for the duration of the study period.

9. Intraarticular (IA) or Intramuscular (IM) corticosteroid (investigational or marketed) in any joint within 3 months of Screening or Oral corticosteroids (investigational or marketed) within 1 month of Screening.

10. IA hyaluronic acid (investigational or marketed) in the index knee within 6 months of Screening

11. Any other IA intervention or therapy within 3 months of Screening .

12. Regular use of opioids/opiates within 4 weeks of Day 1 equivalent to >30mg codeine per day, for 5 days or more, unless participant agrees to a washout period of at least 4 weeks prior to Day 1.

13. High dose NSAIDs within the last month, defined as at the maximum dose recommended for the symptomatic treatment of arthritis pain (e.g., diclofenac ≥150 mg/day, aceclofenac ≥100 mg/day, meloxicam ≥15 mg/day, naproxen ≥1,000 mg/day, piroxicam ≥20 mg/day, and ibuprofen >2,400 mg/day), unless participant agrees to a washout period of at least 4 weeks prior to Day 1.

14. Bleeding disorders, currently taking anticoagulants or has received anticoagulants within 28 days of Day 1, with the exception of low dose aspirin up to150mg daily.

15. Regular use of and not prepared to abstain from glucosamine, fish oil, curcumin and other complementary medicines/supplements, that may affect the study results. A washout period of minimum of 4 weeks will apply prior to Day 1, except in the case of fish oil, where 3 month washout will apply.

16. Positive urine dipstick pregnancy test at screening or Day 1, currently pregnant and/or breastfeeding.

17. Women of child bearing potential (WOCBP) who:

    1. Are not currently using effective methods of contraception and
    2. have not been using effective methods of contraception for 14 days prior to Day 1 and
    3. are not willing to use effective methods of contraception throughout the study

18. History of or known presence of alcohol abuse or illicit drug use, any surgical history, clinically significant conditions (i.e renal or urological disease, cardiac disease, liver disease, gastrointestinal disease or any other significant disease) or organ dysfunction that in the opinion of the investigator may affect the participant's ability to participate in the study or the study results.

19. Currently hospitalised or any planned hospitalisations during the study or up to 1 month following the last dose of study product that may affect the participants ability to comply with the study in the opinion of the medical investigator.

20. Received an investigational drug within 3 months of Day 1 that in the opinion of the investigator may affect the applicant's ability to participate in the study or the study results.

21. Known or suspected allergies to the investigational products

22. History of an adverse reaction or known hypersensitivity to seafood or shellfish.

23. Hypertension (blood pressure ≥140/90 mmHg at screening. (Participants with an elevated BP at screening may be included if they are able to provide a treating doctor letter stating either that they do not have hypertension or that their hypertension has been well controlled for at least 4 weeks).

Double-blind