Past, present and future of therapies in pediatric sarcomas

Progress of oncolytic viruses in sarcomas

Oncolytic virotherapy has shown exciting promise for the treatment of many types of solid tumors. Pediatric sarcomas are an aggressive type of pediatric malignancy known to show limited responsiveness to current therapies, leading to unacceptably high morbidity and mortality. Oncolytic viruses have only recently been used for the treatment of this challenging cancer, and results have been encouraging. Five clinical trials are currently open evaluating the use of oncolytic viruses in pediatric malignancies. Advances in genetic engineering of the viruses include improving the ability of the virus to infect tumor cells, engineering the virus with transgenes which improve the virus' ability to kill tumor cells and manipulating the virus to enhance concomitantly administered therapies. Further understanding of the antiviral immune response and a viral induced anti-tumor immune response will permit a maximization of oncolytic virotherapy.

Educational paper. The development of new therapies for pediatric oncology

Although cure rates for children with cancer are approximately 70%, improvements in cure rates have slowed in the past decade, likely due to our inability to further improve outcome using currently available drugs. Novel drug approaches are needed for children with difficult-to-treat malignancies, such as stage IV neuroblastoma, sarcomas, brain tumors, and relapsed leukemia. Several novel agents show promise for improving outcome in patients with either high risk or recurrent disease. For leukemia, inhibitors of cell cycle progression, such as clofarabine and nelarabine, have shown great promise in their ability to increase treatment efficacy in high-risk disease. Targeted agents such as tyrosine kinase inhibitors, DNA binding compounds (trabectedin), and monoclonal antibodies (GD2 inhibitors for neuroblastoma and anti-CD22 antibodies for pre-B acute lymphocytic leukemia (ALL)) also show promise for future treatment. Extensive reviews of each of these agents are presented elsewhere; this article provides an overview of molecular agents at different stages of FDA/EMA approval; those that are currently approved for use in children, currently approved for use in adults, as well as those that show promise in early clinical trial testing, or are supported by strong preclinical data.