Evaluation of Intra-Articular Injection of Allogeneic Adipose Tissue-Derived Mesenchymal Stem Cells Versus Placebo in Patients with Knee Osteoarthritis

The primary objective of this study is to assess the **safety** and clinical efficiency of intraarticular knee injection of adipose-derived mesenchymal stem cells (AD-MSC) compared to a placebo injection in patients with knee osteoarthritis. This evaluation is clinically relevant as it aims to determine the potential of AD-MSC therapy to alleviate symptoms and improve joint function, offering a novel therapeutic approach for managing knee osteoarthritis.

Secondary objectives include:

• To objectively evaluate whether AD-MSC treatment leads to cartilage regeneration as assessed by MRI, using the MRI Osteoarthritis Knee Score and Quantitative MRI protocol.
• To evaluate whether AD-MSC treatment results in pain reduction, measured on a Numerical Rating Scale (NRS).
• To objectively assess whether AD-MSC treatment leads to improvement in function and clinical signs based on clinical examination, including range of motion, effusion tests (swelling), knee diameter on the patellae (swelling), and atrophy (measurement of quadriceps muscle bulk 10 cm above the patellae top).

The clinical trial focuses on evaluating the safety and clinical efficiency of intraarticular knee injection of adipose-derived mesenchymal stem cells in patients with **knee osteoarthritis**. The study population includes both male and female participants, aged between 40 and less than 75 years, who experience chronic knee pain for at least six months with a Numeric Rating Scale (NRS) score of 4 or above at its worst. Participants are required to have Grade II-III osteoarthritis according to the Kellgren Lawrence Classification, with a joint width space of 1-3 mm, and no more than 5 degrees of valgus/varus deformity as determined by axial hip, knee, and ankle x-ray. The trial excludes vulnerable populations and includes individuals with a Body Mass Index (BMI) of less than 35. Participants must be Danish speakers, legally competent, and able to provide written consent. The sponsor has not provided information regarding the total number of participants in the trial.

The clinical trial is designed to evaluate the safety and clinical efficacy of **allogeneic adipose tissue-derived mesenchymal stem cells** (AD-MSC) for the treatment of knee osteoarthritis. This study is a randomized, double-blind, controlled trial, with participants receiving either the investigational product or a placebo via intra-articular injection. The trial is exploratory in nature, focusing on the mode of action of the AD-MSC therapy. The estimated duration of the trial is four years, commencing in October 2023 and concluding in October 2027.

Participants will undergo a series of study visits, beginning with an inclusion (screening) visit to assess eligibility based on specific criteria, such as age, chronic knee pain, and osteoarthritis grade. Following successful screening, participants will be randomized to receive either the AD-MSC treatment or a placebo. Subsequent follow-up visits will be scheduled to monitor knee symptoms, adverse events, and other clinical outcomes. These visits will include assessments using the Knee Injury and Osteoarthritis Score (KOOS), pain diaries, and MRI evaluations for cartilage regeneration. The end-of-study visit will mark the completion of the trial for each participant, where final assessments will be conducted.

The expected length of participant involvement is approximately one year, during which they will be closely monitored for any adverse events and changes in knee symptoms. Conditions that may lead to early termination from the study include the occurrence of significant adverse events or withdrawal of consent by the participant. The primary endpoints of the study are knee symptoms and adverse events, while secondary endpoints include cartilage regeneration, pain levels, range of motion, and other physical assessments. The trial aims to provide valuable insights into the potential benefits and safety of AD-MSC therapy for individuals with knee osteoarthritis.

The clinical trial involves the administration of **allogeneic adipose tissue-derived mesenchymal stem cells expanded** (AD-MSC) as the experimental treatment. This product, identified by the sponsor product code allo-AD-MSC-2023, is provided as a **suspension for injection in a pre-filled syringe**. Each syringe contains 20 million cells in 10 mL of saline. The route of administration is **intra-articular injection**, specifically targeting the knee joint. The AD-MSCs are derived from adipose tissue and are classified as an advanced therapeutic medicinal product. The primary objective of the trial is to evaluate the safety and clinical efficacy of these stem cells in treating knee osteoarthritis.

In addition to the experimental treatment, the study utilizes a placebo control. The placebo is a **solution for infusion** containing **sodium chloride** at a concentration of 9 mg/mL. This solution is manufactured by Fresenius Kabi AB and is also administered via **intra-articular injection**. The sodium chloride solution serves as a comparator to assess the effects of the AD-MSC treatment against a standard saline injection. The placebo is chemically derived and is not classified as an advanced therapeutic product.

Another sodium chloride solution, branded as Natriumklorid "B. Braun", is also used in the study. This product is a **solution for injection/infusion** and is produced by B.Braun Melsungen AG. Like the Fresenius Kabi product, it is administered through **intra-articular injection**. The use of these sodium chloride solutions ensures that the study can effectively compare the therapeutic effects of the AD-MSCs against a chemically inert substance, maintaining the integrity of the trial's placebo-controlled design.

Efficacy in the clinical trial will be assessed through a series of primary and secondary endpoints. The primary endpoint focuses on evaluating knee symptoms using the Knee Injury and Osteoarthritis Outcome Score (KOOS). Additionally, a pain diary will be maintained for the first 30 days following treatment with allogeneic adipose tissue-derived mesenchymal stem cells (AD-MSC) or placebo, and adverse events will be monitored for one year post-treatment.

Secondary endpoints include assessing cartilage regeneration using the MRI Osteoarthritis Knee Score and a quantitative MRI protocol. Pain levels will be measured using the Numeric Rating Scale (NRS). Other secondary measures include range of motion, effusion tests to evaluate swelling, knee diameter at the patellae, and atrophy assessment by measuring quadriceps muscle bulk 10 cm above the patellae top. These assessments will provide a comprehensive evaluation of the treatment's efficacy in managing knee osteoarthritis symptoms.