The impact of carboplatin and toceranib phosphate on serum vascular endothelial growth factor (VEGF) and metalloproteinase-9 (MMP-9) levels and survival in canine osteosarcoma.

In this pilot study, 10 dogs with osteosarcoma (OSA) were treated with amputation and subsequent carboplatin chemotherapy (300 mg/m2 IV q3wk × 4 doses) followed by toceranib phosphate (2.75 mg/kg PO q48h starting at day 14 post carboplatin). Monthly clinical monitoring and serum measurements of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-9 (MMP-9) were acquired. No dogs were removed from the study due to toxicity. Levels of VEGF and MMP-9 did not change over time. Seven dogs died related to local recurrence and/or pulmonary or bone metastasis and the remainder died of other causes. Median OSA-free survival was 238 d with 34% 1-year progression-free survival. Median overall survival was 253 d with 30% alive at 1.5 y and 10% alive at 2 y. Although this regimen was well-tolerated, survival times did not exceed previously published data from dogs treated with amputation plus chemotherapy alone.