Natural Killer Cells(Instituto de Investigación Hospital Universitario La Paz)

This is an exploratory therapeutic study (according to the terminology of the "ICH Harmonised Tripartite Guideline Topic E8. General Considerations for Clinical Trials". EMEA, March 1998. CPMP/ICH/291/95), open-label, non-randomized, multicenter study. It is considered phase I/II since the safety and efficacy of the infusion of allogeneic haploidentical NK cells in combination with chemotherapy and/or radiotherapy in the treatment of pediatric, adolescent and young adult patients with refractory sarcoma will be sought.