Leukemia is cancer that begins in the bone marrow and involves abnormal white blood cells (WCB) from lymphatic tissues and bone marrow. Scientists have new theories as to why certain children have a longer remission than their peers once they have received CAR-T cell therapy to treat leukemia. It is now believed that base-edited T-cells will make a difference.
A New Treatment Option
As reported in Gilmore Health News, Scientists at London’s University College have developed a new treatment for children with acute lymphoblastic leukemia (ALL). T cells have been configured by the use of gene editing techniques for children with ALL.
Using the gene editing technique CRISPR, malignant cells are rendered inactive and cease replicating.
Ten children were used in the study who were between the ages of six months and 16 years of age. Significant relapsed CD7+ T cell cancer was evident in the bone marrow. T cells were introduced from healthy volunteers via a method of separating the patients’ blood and returning the balance to circulation (apheresis).
Briefly, the CD7 and CD55 T cell markers were moved, and CAR was added to identify the CD7 T cell receptors which destroyed malignant cells.
As published in Nature Medicine, the researchers used computational analysis to identify a genetic signature of CAR-T cells they believe will be effective long term. CAR-T cells are a type of genetically engineered immune cells that target relapsed or incurable blood cancer.
With the participation of a collaborative team of researchers from Ormond Street (GOSH), and the Sanger Institute, the first step in identifying key markers in this cell population was established. The name of the effort is AUTO1.
Sara Ghorashian, M.D. of the Ormond Institute stated that not only are the characteristics vital to children with ALL but also appear to be beneficial to adults with other types of leukemia.
Other comments were offered by Nathaniel Anderson, M.D. of the Sanger Institute. He said that this is the first time they can rely on their research to provide clues that cause CAR T cells to exist for a greater period and potentially keep children free of cancer after treatment. Dr. Anderson stressed that they are indebted to the children and their families who participated in their research.
ALL is more common among children. The risk factors are genetic abnormalities, radiation exposure, smoking, viral infections, familial history, and chemotherapy. Prognosis, as well as treatment, depends on the type of leukemia, age, and molecular findings. Treatment includes chemotherapy, bone marrow transplant, and radiotherapy.
Ten children were enrolled in the CARPALL study for approximately five years after they had received the CAR-T treatment. The researchers were exposed to a new understanding as to why some CAR-T cells remained in a patient’s bloodstream for a greater length of time whereas others disappeared, allowing the cancer to return.
The cells were analyzed at the genetic level and the researchers identified a “signature” in longer-lasting CAR-T cells. The signature indicated that these long-lasting cells transform into an alternate state, enabling them to police the patient’s body looking for cancer cells. The children continued to donate cells for five years after they had their initial treatment.
This signature could be seen in pediatric patients and adults who were treated with CAR-T cells for other types of leukemia. But the researchers were not able to identify the signature in other types of immune cells. The inference is that the signature may be a marker for longer-lasting cells and may be what causes them to remain in the body.
The Key Genes
The researchers participated in the study by identifying key CAR T-cells that remained in the body for a greater period of time. The team emphasized that the genes provide a point of beginning and a way to improve their effectiveness. The most recent count conducted by Globocan alongside the WHO estimated 471,519 cases involving various subtypes among 38 cancer sites.
Co-senior author and Group Lead Sam Behjati, M.D. commented that the study has been a step forward and illustrates the impact of collaborative science, pioneering research, and genomic science.