Gary K. Schwartz, MD of the Columbia University Medical Center, New York, NY discusses the success and potential of immunology as a treatment for sarcomas. Dr Schwartz explains that sarcoma is a complex cancer, representing 60 different cancers; he continues, highlighting that it now poses as a challenge when doctors are trying to develop new therapies directed at the vast scope of tumor subtypes that need to be considered. He then discusses studies on immunotherapy presented at the 2016 Annual Meeting of the American Society of Clinical Oncology (ASCO), held in Chicago, IL. The first Phase II trial he discusses looked at the effect of a PD-1 inhibitor called pembrolizumab (NCT0230103); PD-1 is a immune checkpoint. Results of the study showed low response rates, of around 15% in 85-90 patients. However, certain subtypes of sarcoma had better response rates. For example, pembrolizumab caused a response in 4 out of 6 patients with undifferentiated pleomorphic sarcoma. In patients with liposarcoma, 1 out of 4 responded also. In a Phase II trial of nivolumab in leiomyosarcoma of the uterus (NCT02428192) however, only one patient responded. Further study is now being done into factors that affect response rates (i.e. the influence of biomarkers). Dr Schwartz suggests that despite the overall low response rates, higher response rates in certain sarcoma subtypes are promising to the future of sarcoma immunotherapies.
