Protection against relapse
Immunotherapy leads to complete remission in 60% -100% of patients with acute lymphoblastic leukemia, but the frequency of relapses, unfortunately, is high. According to the results of a new clinical study conducted at the University of Virginia, children and young adults receiving CAR T-cell therapy for acute lymphoblastic leukemia suffer significantly fewer relapses and have a much better chance of survival when treatment is combined with subsequent transplantation of allogeneic (donor) stem cells.
The clinical trial lasted almost five years. In the group of patients who received CAR T therapy followed by stem cell transplantation, the recurrence rate after two years was less than 10%. According to other studies, the recurrence rate after the standard immunotherapy protocol is 50%, and most of the malignant cells lose the target that CAR targets.
Chimeric antigen receptor (CAR) T-cell therapy is performed by genetically modifying a person's own immune cells and injecting them back into the bloodstream to make them more effective cancer cell killers. This therapy demonstrates a high remission rate – up to 100% – 28 days after its initiation in patients with acute lymphoblastic leukemia. Unfortunately, the recurrence rate is high: as one of the studies showed, after 13.1 months, relapse occurred in 40% of patients.
To determine whether stem cell transplantation could reduce the risk of relapse of acute lymphoblastic leukemia, the researchers observed 50 children and young adults aged 4 to 30 years, with an average age of 13.5 years. Allogeneic stem cell transplantation was performed in 21 patients after CAR T therapy, after 24 months, a relapse in this group occurred in 9.5%. For comparison, all patients who did not receive stem cell transplantation relapsed.
No matter how effective CAR T-cell therapy may be in patients with recurrent leukemia, it is now clear that the best results are achieved when treatment is subsequently supplemented with stem cell transplantation. It is worth noting that many patients choose immunotherapy to avoid stem cell transplantation. But after it, there is a chance to completely cure cancer with the help of transplantation; this study demonstrates this.
The researchers now intend to develop an algorithm that will help identify patients who will need stem cell transplantation in advance.
Article by N.N.Shah et al. A Long-Term Follow-Up of CD19-CAR T-Cell Therapy in Children and Young Adults With B-ALL is published in the Journal of Clinical Oncology.
Aminat Adzhieva, portal "Eternal Youth" http://vechnayamolodost.ru based on UVA materials: Stem Cell Transplants Prevent Relapses of Most Common Childhood Cancer.