The purpose of this study is to confirm whether MAG200 (20M or 100M) will improve pain and function of participants with osteoarthritis of the knee compared with placebo. In addition, the two strengths of MAG200 will be compared.

In this study, participants will receive a single injection of placebo or allogeneic ADMSCs (MAG200) administered by IA injection. Participants will be randomised to receive placebo, or MAG200 at a dose of 20 million cells (20M), or MAG200 at a dose of 100 million cells (100M).

It is anticipated that the study will run for approximately 48 months.

Inclusion Criteria

1. Males and females aged ≥ 35 years to ≤ 75 years inclusive.

2. BMI ≥ 19.0 to ≤ 35.0 kg/m2.

3. Documented clinical diagnosis of OA of the study knee.

4. Documented radiological grading of Grade 2 or Grade 3 medial and/or lateral compartment OA of the study knee.

5. Documented radiological grading of OARSI JSN 1-2 of the medial and/or lateral compartment of the study knee.

6. Primary OA treatment of the study knee already attempted within the last 12 months, defined as:

   1. Prescribed analgesia/anti-inflammatory medication where appropriate, AND
   2. an attempted exercise program prescribed by a physical therapist (e.g., physiotherapist, osteopath) or medical practitioner for at least 8 weeks, AND
   3. weight management, where appropriate.

7. Moderate to severe knee specific activity related pain score on the NRS for Pain over the past week.

8. Moderate to severe knee specific functional limitation on KOOS-PS.

9. Less than 5 degrees varus or valgus knee deformity of the study knee relative to neutral alignment.

Exclusion Criteria

1. Any of the following relating to the study knee:

   1. Radiological evidence of KL Grade 4 OA (involving medial, lateral and/or patellofemoral compartment) or OARSI JSN 3.
   2. History of recurrent mechanical instability and / or locking.
   3. Joint surgery or significant knee injury within 12 months prior to Day 1.
   4. Metal in-situ resulting in metal artefact which impacts/prevents MRI assessment.
   5. MRI confirmed:

   i. Generalised full thickness chondral loss involving tibial and/or femoral weight bearing surfaces ii. Total meniscectomy iii. Complete posterior meniscal root tear iv. Subchondral insufficiency fracture v. Osteonecrosis vi. Malignant bone marrow infiltration vii. Solid tumors viii. Traumatic fracture/bone contusion ix. Knee pathology requiring orthopaedic assessment/intervention (e.g., significant loose body)

2. Other causes of the knee symptoms unrelated to knee OA.

3. Significant and debilitating OA in the non-study knee.

Outcome data of published/reported results

Individual de-identified participant data which underlie results reported in this article will be available upon publication. Material will be accessible to investigators whose proposed use of data has been approved by an independent review committee and for data meta-analysis. Requests are to be directed to the corresponding author of the article. No end date is given for request of data.

Requests are to be directed to the corresponding author of the article (clinicaltrials@magellanstemcells.com.au)