Investigational therapies in phase II clinical trials for the treatment of soft tissue sarcoma.

Introduction: Soft-tissue sarcomas (STS) are a heterogeneous group of diseases that are characterized by a historic lack of active treatment options. However, several new drugs and indications have become available in recent years.

Areas Covered: This article reviews the most relevant phase II studies that utilize chemotherapy agents (aldoxorubicin, amrubicin, trabectedin alone or in combination with doxorubicin, and gemcitabine plus docetaxel), targeted therapies (Imatinib, dasatinib, regorafenib, tivozanib, palbociclib and selinexor), a combination of chemotherapy plus targeted therapies (fucusing on doxorubicin plus olaratumab) and immunotherapies (pembrolizumab, combination of nivolumab plus ipilimumab and adaptive cell therapy) in STS (other than gastrointestinal stromal tumors) (GIST) published from 2015. Some of these strategies are under further clinical development or will likely be assessed in future phase III studies.

Expert Opinion: A series of novel treatments have shown encouraging results in STS in recent years. The most important is the combination of the standard cytotoxic agent doxorubicin plus the platelet-derived growth factor receptor (PDGFR) inhibitor olaratumab, although definitive results from a phase III trial are expected. Immunotherapy has not been as successful in STS so far. However, further investigations are ongoing.