About steroid-resistant aGvHD
Formerly called bone marrow transplant, Hematopoietic Stem Cell Transplantation (HSCT) is the last therapeutic option for patients with certain blood cancers or severe immunodeficiency. In practice, the treatment is designed to replace the diseased blood cells of the patient with the hematopoietic stem cells of a matching donor (allograft).
Once grafted, these stem cells will produce new healthy and functional blood cells, including white blood cells that will allow patients to bridge their immune deficiency or to eliminate surviving cancer cells.
If this technique has made considerable progress in 60 years, half of transplant recipients are still victims of complications: side effects of conditioning pretreatment (that aims to prevent transplant rejection), long-term susceptibility to infections and GvHD. In the latter case, the donor’s over-active T-cells «turn against» the patient’s tissues: mucous membranes, skin, gastro-intestinal tract, liver and lungs. The acute form appears just after the transplant, the chronic form occurring several months later (preceded or not by an aGvHD).
Affecting between 30 to 55% of patients, GvHD is the main complication of transplantation. To halt this “autoimmune disease”, physicians combine corticosteroids with other immunosuppressive agents. The fact remains that some 30 to 50% of aGvHD gradually become resistant to these first-line treatments.
To date clinicians do not have any standard of treatment for these patients for whom there is a strong unmet medical need. Thus in Europe, 4,000 children and adults die each year from their aGvHD.