Mesenchymal stromal cell infusions of umbilical cord-derived mesenchymal stromal cells in children with Recessive Dystrophic Epidermolysis Bullosa (MissionEB): a qualitative sub study of a randomised, double-blind, placebo controlled, crossover, phase 3 trial

Background Recessive Dystrophic Epidermolysis Bullosa (RDEB) is a rare genetic skin condition causing fragile skin, blistering, and scarring. It leads to chronic pain, slow wound healing, and severe limitations, profoundly impacting patient and family quality of life. Umbilical cord tissue-derived mesenchymal stromal cells (UC-MSC) have shown therapeutic promise. The Mission EB trial (ISRCTN14409785; registration date 25/03/2021) assessed UC-MSC safety and effectiveness in children with RDEB in a placebo-controlled, double-blinded, crossover study. Methods This study used a qualitative research design with semi-structured interviews and thematic analysis, to explore Mission EB trial treatment impact on the quality of life of patients and parents. Parents and patients were interviewed at two time points (approximately 3- and 12-months post-randomisation). Purposive sampling included 10 parents and 6 children; 13 individuals (8 adults, 5 children) were interviewed twice (once in each study period). Interviews were transcribed verbatim, independently coded, with overall impressions agreed upon prior to unblinding. Results RDEB significantly impacted daily life, marked by pain and itch. Participants were hopeful of the trial, willing to pursue minor improvements. UC-MSC infusions led to reduced pain/itchiness, improved wound healing, and resulted in fewer self-reported dressing changes. These benefits often translated to increased energy, improved eating, and greater daily activity participation. Benefits were more pronounced with active treatment. Negative effects were minimal, primarily venous access difficulties. Blinded participants could discern active UC-MSC from placebo based on symptom changes; 10 of 13 showed clear differences aligning with treatment. All parents interviewed expressed willingness for their child to receive treatment again. Conclusions This qualitative research provides valuable insights into perceived benefits of UC-MSC treatment for children with RDEB. Interview findings regarding symptom improvement and participants’ ability to discern active treatment shed light on its perceived benefit in RDEB, especially in milder RDEB patients. The study highlights the critical importance of qualitative methodologies in adding to quantitative trial outcomes and capturing the meaningful impact of interventions on the lives of patients and families particularly where quantitative measures may not fully reflect lived experience.