KDR and osteosarcoma: A phase-2 trial investigating the combination of the VEGFR2 inhibitor apatinib and the PD-1 inhibitor camrelizumab in osteosarcoma patients of 11 years old or older reported clinical benefits in 30% of patients at 6 months, an ORR in 21% (9 out of 43 patients), and a median PFS of 6.2 months [60].