Intraglandular treatment with adipose-derived mesenchymal stem cells in patients with xerostomia due to Sjögren’s disease—a study protocol for aphase 1, triple-blinded, randomized, clinical trial

Xerostomia (the subjective feeling of dry mouth) is a prominent symptom in Sjögren’s disease and often related to hyposalivation. Xerostomia and hyposalivation negatively affect the oral health and have a significant negative impact on general health and overall quality of life. There is no curative treatment for xerostomia due to Sjögren’s disease, and the symptomatic strategies are often inadequate. Hence, there is an immense need for a new therapeutic approach. Findings from an increasing number of both preclinical and clinical studies indicate that mesenchymal stem cell transplantation treatment can alleviate xerostomia and enhance salivary flow rate. Therefore, this trial evaluates the efficacy of mesenchymal stem cell injection in both submandibular glands in patients with xerostomia due to Sjögren’s disease. This trial will include 40 patients with primary Sjögren’s disease, xerostomia, and hyposalivation. Forty participants will be included and randomized to either treatment with allogeneic adipose-derived mesenchymal stem cells or placebo (sterile isotonic saline water). Sex stratification is not planned. Participants will be followed for 1 year, with follow up visit 4 and 12 months after treatment. The primary endpoint is to evaluate the efficacy of injection of allogeneic adipose-derived mesenchymal stem cells in both submandibular glands compared to placebo on whole saliva flow rates measured with sialometry. Further, secondary objectives are to measure the following: safety of the intervention measured by patient self-report and lookup in the electronic patient journal, Sjögren’s disease activity measured with European Alliance of Associations for Rheumatology (EULAR) Sjögren’s syndrome disease activity index, and EULAR Sjögren’s Syndrome Patient Reported Index, presence of HLA antibodies after treatment, and 3 Quality-of-Life questionnaires: Clinical Oral Dryness Score, Summated Xerostomia inventory, and Xerostomia Questionnaire. Current treatment of xerostomia due to Sjögren’s disease shows limited efficacy. Therefore, this trial is designed to evaluate the efficacy of mesenchymal stem cell treatment, compared to placebo, on xerostomia due to Sjögren’s disease. EU CT number: 2024–516715-25–00 (Ethics approval: Approved on 21.10.24). Clinicaltrials.gov identifier: NCT06805448 (registered on 21.01.25). https://euclinicaltrials.eu/search-for-clinical-trials/?lang=en&EUCT=2024-516715-25-00