Safety and efficacy of multiple tyrosine kinase inhibitors in pediatric/adolescent and young adult patients with relapsed or refractory osteosarcomas: A single-institution retrospective analysis.

The safety profile of MTKI therapies in pediatric and AYA patients was comparable to that in adult patients. MTKI therapies, particularly regorafenib, against pediatric relapsed osteosarcoma can suppress tumor growth and prolong PFS with tolerable adverse events.