In in vivo xenograft models, SAR405838 was able to induce a significant antitumor activity in different types of tumors characterized by P53 wild-type status but lacking MDM2 amplification and a complete and persistent tumor regression in 100% of mice bearing osteosarcoma cancer cells with wild-type P53 and amplified MDM2 [104]. This evidence concerns the gene TP53 and neoplasm.