NCI Definition: An aggressive malignant neoplasm with a poor response to therapy, usually presenting as stage III/IV disease. It is characterized by the presence of neoplastic cells with morphologic and immunophenotypic characteristics similar to those seen in mature histiocytes. 
There are 2 clinical trials for histiocytic sarcoma, of which 2 are open and 0 are completed or closed. Of the trials that contain histiocytic sarcoma as an inclusion criterion, 2 are phase 2 (2 open).
Cobimetinib and pembrolizumab are the most common interventions in histiocytic sarcoma clinical trials.
2. The AACR Project GENIE Consortium. AACR Project GENIE: powering precision medicine through an international consortium. Cancer Discovery. 2017;7(8):818-831. Dataset Version 6. This dataset does not represent the totality of the genetic landscape; see paper for more information.