Stem Cell Therapy Developed in Murcia Cuts Advanced Osteoporosis Fractures by 94%
A phase 1 clinical trial conducted by researchers in Murcia and Miami has found that a single infusion of modified mesenchymal stem cells reduced fragility fractures by 94% in women with advanced osteoporosis, with no serious adverse events reported over an average six-year follow-up.
A single infusion of a patient's own modified stem cells has been linked to a 94% reduction in fragility fractures among women with advanced osteoporosis, according to the results of a phase 1 clinical trial published in the journal Cell. The experimental therapy, developed through a collaboration between the Hospital Clínico Universitario Virgen de la Arrixaca in Murcia, Spain, and the Miami Veterans Affairs Medical Center in the United States, represents an early but closely watched advance in regenerative medicine for a condition that affects millions of people worldwide.
The trial enrolled ten women between the ages of 51 and 72, all of whom had advanced osteoporosis and had already suffered at least one fragility fracture. Each participant received a single intravenous infusion of mesenchymal stem cells extracted from her own bone marrow, cultured in the laboratory and then modified before being returned to the body. The primary goal of the study was to assess the safety of the approach rather than to prove its effectiveness.
Over an average follow-up period of six years, no participant experienced serious adverse events related to the treatment. Researchers also observed a striking drop in fractures. Before the therapy, the women suffered on average more than one fracture every two years. After the infusion, that frequency fell to nearly zero. Improvements were also detected in bone mineral density, in the area of bone tissue, and in markers associated with bone formation, alongside reduced pain and disability in most of the participants.
The key to the therapy lies in a modification made to the cells before infusion. Using a technique called enzymatic exofucosylation, researchers generate a structure known as HCELL, which helps the cells travel from blood vessels into bone tissue. The scientists describe this mechanism as a «transient GPS». Importantly, the modification does not alter the genetic material of the cells and fades progressively after it has served its purpose, a design feature intended to limit long-term risks.
The research involved additional institutions, including the University of Murcia, the Murcian Institute of Biosanitary Research (IMIB), and groups from the Advanced Therapies Network of the Carlos III Health Institute. Their combined expertise in cell biology, immunology, and clinical care made the trial possible, though the authors stress that the findings remain preliminary.
Because only ten women took part and the study lacked a control group, the researchers caution that the results cannot conclusively demonstrate the treatment's efficacy. The trial was designed primarily to establish safety, and the observed reduction in fractures, while dramatic, must be confirmed in larger, controlled studies. A larger trial is already planned for 2027, which should provide more robust evidence about whether the therapy can become a standard option for patients with severe osteoporosis.
Osteoporosis is a condition in which bones become weak and brittle, making even minor falls or everyday movements capable of causing fractures. It is particularly common in postmenopausal women. Current treatments often rely on medications that slow bone loss or stimulate bone formation, but they do not always prevent fractures in advanced cases. A therapy that uses a patient's own cells to rebuild bone tissue could offer a new approach, though questions about cost, scalability, and long-term durability remain unanswered.
The publication of the trial in Cell gives the work a significant platform, and the involvement of both Spanish and American institutions highlights the growing role of international collaboration in regenerative medicine. For now, the researchers present their results as a promising signal rather than a proven cure, and they emphasize that further study is needed before the therapy can be considered for widespread clinical use.
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