Acute lymphoblastic leukaemia is the most common malignant disease in childhood. Although overall survival is 85% in Spain, it decreases to 30-50% in patients who relapse or do not respond to chemotherapy. To promote research and improve treatments, the Spanish Society of Paediatric Haematology and Oncology (SEHOP) created the ReALLNet network in 2021. It is an initiative coordinated by Dr. Pablo Velasco, paediatrician at the Paediatric Oncology and Haematology Service of the Vall d'Hebron Hospital and member of the Childhood Cancer and Blood Disorders group of the Vall d'Hebron Research Institute (VHIR), and Dr. Jose Luis Fuster, head of the Paediatric Oncology and Haematology Service of the Hospital Clínico Universitario Virgen de la Arrixaca and member of the Murcian Institute of Biosanitary Research (IMIB), with the participation of 47 professionals from all over Spain. The results of the pilot test carried out in this network so far have recently been published in Frontiers in Pediatrics.

The Relapsed Acute Lymphoblastic Leukaemia Network (ReALLNet) was born as a bridge between care and research in this paediatric disease so that advances are efficiently transferred to all centres in Spain equally. "With ReALLNet, we are joining forces to make it easier for every child and adolescent to have access to the most advanced and personalised treatment options", says Dr Pablo Velasco.

To this end, a multidisciplinary committee composed of leukaemia experts from clinical, diagnostic, research and even mathematical backgrounds has already been established. This group is responsible for analysing and evaluating cases of patients with relapsed or refractory acute lymphoblastic leukaemia based on genetic testing and new studies such as functional assays, in order to make informed decisions about the most appropriate treatment approach for the patient.
The creation of a registry that includes the clinical and biological data of all children and adolescents and which collects clinical decisions and responses to treatment is also among the various ReALLNet initiatives. A protocol has also been implemented to facilitate the transport of samples from these patients to the network's diagnostic centres, La Paz University Hospital and Sant Joan de Deu Hospital, and the centres for functional studies at the University of Barcelona and Josep Carreras Leukaemia Research Institute, as well as to the project's biobanks, to store them for research purposes.

The ReALLNet team also proposes to generate a therapeutic recommendation guideline that applies the latest advances obtained in recent years and is applicable to all patients in first relapse who, for any reason, are unable to participate in available clinical trials.

Finally, ReALLNet has also developed a software tool to help healthcare professionals find clinical trials in which their patients can participate.

ReALLNet works together with the SEHOP-PENCIL study, led by Vall d'Hebron, which aims to facilitate access to personalised medicine for all children and adolescents with cancer, regardless of their residence. In this case, ReALLNet serves as a platform focused on haematological cancers.