25Childhood cancer is one of the leading causes of disease-related mortality among children and adolescents. Although it is relatively rare compared to cancer in adults, its impact is devastating. Among the most common types of pediatric neoplasms are hematologic tumors, such as acute lymphoblastic leukemia (ALL), which accounts for approximately 25% of all childhood cancers.
In recent years, oncological medicine has been profoundly transformed by the advancement of immunotherapies. Among them, CAR-T cell therapy (Chimeric Antigen Receptor T-cell therapy) stands out as one of the most innovative and promising approaches in the fight against hematologic cancers, particularly in pediatric cases that are refractory to conventional treatments.
This article provides a comprehensive overview of the use of CAR-T therapy in pediatric hematology-oncology, addressing its mechanism of action, clinical efficacy, challenges, and the pioneering role of Celluris in the development and democratization of this technology in Brazil and Latin America.
What is CAR-T Cell Immunotherapy?
CAR-T cell immunotherapy is a form of personalized treatment that uses the patient’s own immune system to fight tumor cells. The technique involves collecting the patient’s T lymphocytes, which are subsequently modified in the laboratory to express specific receptors, known as CARs, capable of recognizing tumor antigens such as CD19, present on leukemic B cells.
These modified cells are then expanded in number and reinfused into the patient’s body, where they begin to act as “hunters” of tumor cells. This mechanism allows for highly specific action, with the potential to achieve complete remissions even in patients with cancer resistant to multiple lines of treatment.
Applications in Pediatric Oncology
The primary application of CAR-T therapy in pediatrics has been in the treatment of relapsed or refractory B-cell acute lymphoblastic leukemia. Children and adolescents who do not respond to traditional chemotherapy or who relapse after bone marrow transplantation now have, with CAR-T therapy, a new therapeutic possibility.
Clinical studies conducted in several countries have demonstrated impressive response rates, with complete remission achieved in approximately 80% of cases treated with CAR-T targeting the CD19 antigen. The use of this therapy also extends to B-cell lymphomas and is currently being investigated for other types of hematologic cancers and even solid tumors, although additional challenges remain.
Advantages of CAR-T Therapy in Pediatric Patients
One of the greatest advantages of CAR-T therapy in children is the depth of the responses achieved, even in cases of advanced disease. The possibility of achieving complete remission with a single infusion of cells represents a paradigm shift compared to prolonged treatments involving chemotherapy and radiotherapy.
In addition, the specificity of CAR-T therapy may allow for a significant reduction in long-term toxicity, which is particularly important in pediatric patients whose growth and development may be affected by aggressive therapies. This translates into improved quality of life and fewer long-term complications.
Another favorable aspect is the personalization of the treatment. Since CAR-T cells are produced from the patient’s own cells, there is a lower risk of rejection and adverse immunological effects, contributing to the safety of the procedure.
Adverse Effects and Associated Risks
Despite its benefits, CAR-T immunotherapy is not without risks. One of the main side effects observed is cytokine release syndrome (CRS), an intense systemic inflammatory response caused by the massive activation of CAR-T cells. In some cases, CRS can be severe and require intensive care.
Another possible adverse effect is neurological toxicity, known as immune effector cell-associated neurotoxicity syndrome (ICANS), which may manifest as confusion, seizures, and other transient neurological symptoms. Although these effects are generally manageable with appropriate clinical support, they require treatment centers to be equipped with specialized infrastructure and experienced multidisciplinary teams.
In addition, uncertainties remain regarding the durability of response and the persistence of CAR-T cells in the body, especially in the long term. The possibility of relapse also exists, particularly in cases where the tumor loses the expression of the antigen targeted by the therapy.
Challenges for the Adoption of CAR-T in Pediatrics
The introduction of CAR-T therapy into routine pediatric hematology-oncology faces significant obstacles. One of the main challenges is the logistical and technical complexity involved in the production of the cells. The process requires certified laboratories, high-technology equipment, trained teams, and a robust regulatory system.
Another challenge is the high cost of the therapy, which limits access in many countries. In the United States and Europe, the price of a CAR-T infusion can exceed US$400,000 for the product alone. In countries with fewer resources, such as Brazil, this cost makes the treatment inaccessible to most patients unless local production and supportive public policies are implemented.
Decentralizing production and developing national platforms are essential to enable broader access to CAR-T therapy. This requires investments in research, infrastructure, and partnerships between public and private institutions.
Hospital Adaptation and Public Policies for CAR-T Implementation
In addition to clinical and logistical barriers, there is a need for structural transformation within treatment centers. The approval of therapies such as tisagenlecleucel led to the creation of national plans for the incorporation of advanced therapies, as observed in Spain. These plans include the certification of hospital centers capable not only of administering CAR-T therapy but, in some cases, also producing it internally. This verticalization of the process aims to increase autonomy, reduce costs, and accelerate patient access to these therapies.
For CAR-T therapy to be successfully integrated into routine pediatric hospital care, institutions must adapt their care models. This involves creating specialized clinical committees and implementing specific workflows for patient selection, monitoring, and follow-up. Without alignment between therapeutic innovation and hospital infrastructure, the potential of CAR-T therapy may be underutilized, particularly among vulnerable pediatric populations with limited access to reference centers.
The Need for Specialized Centers
For CAR-T therapy to be effectively incorporated into pediatric oncology, hospitals must be prepared for its administration. This implies not only having access to the technology but also having specialized inpatient units, well-defined clinical protocols, and multidisciplinary teams trained to manage adverse effects and provide post-treatment follow-up.
In addition, some centers may also become involved in the manufacturing of the cells, creating a more self-sufficient and agile model. This would represent a significant advance in consolidating immunotherapy as an integral part of the oncological therapeutic arsenal.
Future Perspectives of CAR-T in Pediatrics
The future of CAR-T therapy is promising and involves several avenues of expansion. Research is underway to develop new generations of CAR-T cells that target antigens beyond CD19, expanding the indications of the therapy to other types of leukemias, lymphomas, and even solid tumors.
There are also studies focused on combining CAR-T therapy with other therapeutic strategies, such as immune checkpoint inhibitors, targeted therapies, and even low-dose chemotherapy, in order to enhance clinical outcomes.
Another expected advance is the reduction of costs and the simplification of production logistics, which may allow the therapy to be performed in medium-sized centers, further expanding its reach.
The Transformative Impact of CAR-T in Pediatric Oncology
CAR-T cell immunotherapy represents a true revolution in pediatric hematology-oncology. With its potential to cure diseases previously considered untreatable, it offers new hope for children and adolescents with refractory leukemias and lymphomas.
However, for this hope to become a reality for all patients, it is necessary to address the logistical, financial, and structural challenges associated with its implementation. Companies such as Celluris play a central role in this process by developing local technological solutions, promoting equitable access, and placing Brazil at the forefront of biotechnology applied to cancer treatment.
The future of pediatric oncology will undoubtedly involve the expansion and consolidation of CAR-T therapy, and with the involvement of innovative and committed initiatives, this future is increasingly within reach.
Read also on our blog about CAR-T Cell Therapy in Autoimmune Diseases and Allergies: The Next Frontier of Personalized Medicine.
