modification of the intervention before patient's enrollment, new protocol submitted

To date, allogeneic haematopoietic stem cell transplantation (aHSCT) is the only curative treatment for many paediatric and young adult haematological pathologies (acute leukaemia, myelodysplastic syndromes, haemoglobinopathies, bone marrow aplasia, severe combined immunodeficiency). Despite the major therapeutic progress made over the last 50 years, particularly in terms of supportive care, post-transplant morbidity and mortality remains high. Infectious complications, whose incidence varies between 30 and 60%, are the first cause of mortality in the immediate post-transplant period.

In order to protect the patient from the occurrence of severe infectious episodes, aHSCTmust be performed in a highly protected environment (positive pressure chambers).

This has implications for the experience and impact of hospitalization on the patient and family. This is particularly true in paediatrics, whether in children, adolescents or young adults, where it is not only the patient's quality of life that is at stake, but also their emotional and psychomotor development. In these patients, prolonged hospitalization (at least 6 weeks) in a sterile room will be responsible for physical deconditioning accompanied by a decrease in muscle mass, itself concomitant with undernutrition, and an increase in sedentary lifestyle. This prolonged hospitalisation in a sterile room, associated with myeloablative treatments, is therefore the cause of social isolation of patients, but it is also often synonymous with physical inactivity leading to a rapid decrease in physical condition, quality of life and an increase in fatigue.

Today, the benefits of physical activity (PA) during and after cancer treatment have been widely demonstrated.

The objective is to evaluate the feasibility of an adapted physical activity program during the isolation phase for achieving aHSCT in children, adolescents and young adults. This is a prospective, interventional, monocentric cohort study conducted at the Institute of Paediatric Haematology and Oncology in Lyon. The intervention will take place during the isolation phase and consists of an adapted physical activity (APA) program defined at inclusion, integrating supervised sessions with an APA teacher, as well as autonomous sessions. The program is individualized according to age, aerobic capacity, and PA preferences. Sessions are also tailored to the biological, psychological, and social parameters of patients.

The total duration of the intervention is 3 months. To date, no PA studies have been performed in patients under 21 years of age requiring aGCSH during the sterile isolation phase. EVAADE will therefore be the first study in this population to offer an innovative procedure with a connected device.

Inclusion Criteria:

• 8 years ≤ Age ≤ 21 years
• Size more or equal to 110 cm.
• Histologically or cytologically confirmed malignant or non-malignant haemopathy
• Indication for hematopoietic stem cell allograft.
• Hospitalization in a protected room at IHOP/DAJAC.
• Certificate of no contraindication to the practice of an APA, issued by the oncologist or attending physician.
• Having available in the sterile room a smartphone (iPhone 5S version for Apple/version 5 under Android at least) or a tablet (for the realization of the connected challenges) during the whole hospitalization period.
• Written consent signed and dated by the patient or the parents of minor patients with the acceptance of the minor.

Exclusion Criteria:

• Severe Heart Disease and Uncontrolled Cardiovascular Disease