Evaluation of Intra-Articular Injection Tolerance of Autologous Adipose Tissue-Derived Stromal Vascular Fraction in Adults with Rhizarthrosis Stages DELL 1-3

The primary objective of this study is to evaluate the **tolerance** at 6 months of intra-articular injection of autologous stromal vascular fraction (FVS) for the treatment of rhizarthrosis. This is clinically relevant as it aims to determine the safety and potential adverse effects of this treatment modality, which could influence its adoption in clinical practice for managing rhizarthrosis, a degenerative joint condition affecting the thumb.

Secondary objectives include assessing the efficacy of intra-articular injection of FVS at 1, 3, and 6 months on various clinical outcomes: - Functional level - Pain - Cartilage regeneration - Overall tolerance

These secondary objectives are crucial for understanding the broader therapeutic potential and impact of FVS on patient quality of life and joint health, beyond its safety profile.

The clinical trial involves **adults** diagnosed with rhizarthrosis at DELL stages 1 to 3. The study population includes both **male** and **female** participants, with an age range starting from 18 years and above. Participants are required to have undergone symptomatic medical treatment for at least six months, which has become ineffective, indicating a surgical stage. The trial population was selected based on specific criteria, including a pain score of 4 or higher on the EVA scale and a Quick Dash or PRWHE score of 20/100 or more. Participants must be affiliated with a social security scheme and have provided informed consent. Women of childbearing age are required to use effective contraception, while men must ensure surgical sterility or use mechanical contraception. The sponsor has not provided the total number of participants involved in the study.

The clinical trial is designed to evaluate the **tolerance** of intra-articular injection of **autologous adipose tissue-derived stromal vascular fraction** for the treatment of rhizarthrosis in adults. This study is a Phase IV, randomized, double-blind, controlled trial, with an estimated duration from February 2024 to November 2025. The trial involves a series of structured visits, beginning with an inclusion (screening) visit, followed by follow-up visits at 1, 3, and 6 months, and concluding with an end-of-study visit. The primary objective is to assess the number of treatment-attributable Grade ≥ 3 adverse reactions over a 6-month period post-injection. Secondary endpoints include functional assessment of the hand, pain evaluation, cartilage regeneration, and adverse event monitoring at specified intervals.

Participants will be involved in the study for approximately 6 months. Inclusion criteria require participants to be adults aged 18 years or older with rhizarthrosis DELL stage 1 to 3, who have experienced ineffective symptomatic medical treatment for at least 6 months. Participants must have an EVA pain score of ≥ 4 and a Quick Dash or PRWHE score of ≥ 20/100. Women of childbearing age must use effective contraception, and men must ensure surgical sterility or mechanical contraception. Conditions for early termination from the study include the occurrence of severe adverse reactions or withdrawal of consent by the participant. The investigational product is administered via intraarticular use, with a maximum daily dose of 5 million cells. The study aims to provide valuable insights into the safety and efficacy of this advanced therapy medicinal product in the specified patient population.

The clinical trial involves the administration of an **experimental medication** known as **Autologous Adipose Tissue-Derived Stromal Vascular Fraction 5 Millions Cells**. This medication is formulated as a **cell suspension for injection**. The active substance, **autologous adipose tissue-derived stromal vascular fraction**, is a structurally diverse substance used in cell therapy. The pharmaceutical form is specifically designed for **intraarticular use**, targeting the treatment of rhizarthrosis. The dosage is set at a maximum of 5 million cells per milliliter, with a total dose not exceeding 5 million cells. The treatment period is limited to a single administration, ensuring a controlled exposure to the therapeutic agent. The product is classified as an Advanced Therapy Investigational Medicinal Product (ATIMP) and is categorized under somatic cell therapy medicinal products.

In this study, no non-experimental treatments such as standard-of-care therapy, placebo, or comparator treatments are utilized. The focus remains solely on evaluating the tolerance of the intra-articular injection of the stromal vascular fraction. Participant compliance with the dosing schedule is monitored to ensure adherence to the protocol. The trial aims to assess the safety and tolerance of this innovative treatment approach over a period of six months, providing valuable insights into its potential therapeutic benefits for individuals with rhizarthrosis.

Efficacy in this clinical trial will be assessed through a series of primary and secondary endpoints. The primary endpoint focuses on the number of treatment-attributable Grade ≥ 3 adverse reactions occurring over a 6-month period following the intra-articular injection of **stromal vascular fraction** (FVS) for the treatment of rhizarthrosis. This will provide a measure of the treatment's safety and tolerance.

Secondary endpoints will evaluate various aspects of functional and symptomatic improvement. These include functional assessment of the hand using the Kapandji score, JAMAR and Key pinch tests, active mobility of the trapezio-metacarpal joint in antepulsion and abduction, the Grinding test, and the DASH and PWRHE quick scores. These assessments will be conducted at 1, 3, and 6 months post-treatment. Pain levels will be measured using the EVA scale, alongside monitoring the progress of long-term analgesic treatment. Additionally, cartilage regeneration will be evaluated through MRI and X-ray imaging of the trapezio-metacarpal joint at the same timepoints. Adverse events will be systematically recorded using EvI/EvIG data collection methods.