Spanish researchers have achieved a groundbreaking success in the fight against acute lymphoblastic B-cell leukemia. A new immunotherapy called CAR-STAb, developed in Spain, has proven to be extremely promising in preclinical studies. This development could open up a new treatment perspective, especially for children suffering from the most common form of childhood cancer.
CAR-STAb: A Breakthrough for Resistant Leukemia Cases
The CAR-STAb therapy aims to treat blood cancer cases that do not respond to conventional chemotherapy or where existing immunotherapies do not show sufficient effect. This is a crucial step, as many patients who respond to current immunotherapies still relapse. The study, published in the renowned Journal for Immunotherapy of Cancer, describes in detail how CAR-STAb delivers convincing results in animal models by mobilizing a larger number of defense cells in the body to fight tumor cells more effectively than previous approaches.
The Minds Behind the Innovation: A Team of Top Spanish Researchers
Leading this research are Luis Álvarez-Vallina, Head of the Clinical Research Unit for Cancer Immunotherapy at Hospital Universitario Doce de Octubre and the Spanish National Cancer Research Center (CNIO), as well as Clara Bueno and Pablo Menéndez from the Josep Carreras Leukemia Research Institute. Their common goal is to apply for approval for a clinical trial as early as 2026, thus bringing CAR-STAb therapy closer to patients.
The Enormous Potential of Immunotherapies
B-cells or B-lymphocytes are an essential part of our immune system. Their main task is to identify and neutralize threats. However, a malfunction of these cells can lead to severe diseases such as acute lymphoblastic B-cell leukemia – an aggressive form of blood cancer that, although most common in children (35% of childhood cancer cases), can affect people of all ages.
Currently, chemotherapy is the primary treatment option. If this fails, immunotherapies are used. These include bispecific antibodies, which bring T-lymphocytes into contact with tumor cells, and CAR-T cell therapy, in which the patient’s own T-lymphocytes are modified and reinjected to specifically attack tumor cells. Although both approaches have significantly improved the treatment of resistant cases, there is still room for optimization, as many patients do not respond or experience relapses.
CAR-STAb: The Combination Makes the Difference
The new immunotherapy CAR-STAb combines the best of both worlds: It is a CAR-T therapy that produces a bispecific antibody. This allows CAR-STAb lymphocytes to recognize tumor cells in two different ways, making it harder for them to escape. Another decisive advantage is the ability to recruit unmodified T-cells in the tumor environment, which significantly increases the number of defense cells involved in fighting cancer.
Javier Arroyo, a researcher in Álvarez Vallina’s group at Hospital Universitario Doce de Octubre, explains: “The fact that we use different mechanisms and different points of attack means that if the tumor cell tries to evade immunotherapy, it can be subdued on the one hand. This makes it more difficult for the cell to escape the control of the immune system.” This innovative approach has the potential to sustainably change the treatment landscape for patients with acute lymphoblastic B-cell leukemia.
References
Luis Álvarez Vallina, Clara Bueno, Pablo Menéndez, et al. CD22-CAR T cells secreting CD19 T cell engagers for improved control of B-cell acute lymphoblastic leukemia progression. Journal of Cancer Immunotherapy (2025). DOI: https://doi.org/10.1136/jitc-2024-009048
