The perplexing role of immuno-oncology drugs in osteosarcoma.

• Osteosarcoma outcomes have not improved since use of cytotoxic chemotherapy. • Addition of macrophage activators and interferon have been disappointing. • Combination therapies may be needed to exploit the role of the immune system. Osteosarcoma is a rare, primary tumour of bone. Curative treatment consists of multi-agent chemotherapy and complete surgical resection. Despite the use of multi-agent chemotherapy, the risk of recurrence is high. Survival outcomes for patients with osteosarcoma have not changed since the 1980′s. Based on biologic rationale, there has been interest in adding immunotherapies to upfront curative intent chemotherapy, including mifamurtide (a macrophage activator) and interferon. However, results to date have been disappointing. In the metastatic setting, checkpoint inhibitors alone have not proven effective. Ongoing translational work is needed to further understand which patients may benefit from immune-oncology approaches with standard cytotoxic chemotherapy. [ABSTRACT FROM AUTHOR]