Eribulin Inhibits Osteosarcoma in a Clinically-accurate Bone-tumor-insertion PDOX Mouse Model.

BACKGROUND/AIM Osteosarcoma is a rare type of bone cancer that affects mostly children and adolescents. First-line chemotherapy for osteosarcoma has not been improved for many decades. Eribulin has been used to treat breast cancer and liposarcoma in the clinic. MATERIALS AND METHODS A patient-derived orthotopic xenograft (PDOX) mouse model of osteosarcoma was established by tumor insertion within the tibia. This model more closely mimics osteosarcoma in clinical settings and was used to test the efficacy of eribulin. Tibia-insertion osteosarcoma PDOX mouse models were randomized into two groups: a control group (n=4) and an eribulin-treatment group (n=5). Mice were treated for fourteen days, four weeks after initial implantation. Tumor size and body weight were measured, and tumor histology was examined. RESULTS Significant tumor growth inhibition (p=0.044) was observed in mice treated with eribulin compared to the control group. Histology demonstrated necrosis in the eribulin-treated tumors. There was no body-weight loss in the treated mice. CONCLUSION Eribulin may be a clinically-effective, off-label chemotherapy for recalcitrant osteosarcoma that has failed first- and second-line therapy.