Safe and effective use of cabozantinib and nivolumab in stabilizing disease progression of tissue sarcoma after multiple lines of standard therapy

Abstract

Introduction: Soft-tissue sarcomas (STS) are a rare and varied group of tumors with limited treatment options. In recent years, immune checkpoint inhibitors have demonstrated efficacy in an increasing number of solid tumors. Nivolumab, a PD1-inhibitor, demonstrates improved overall survival (OS) and progression-free survival (PFS) in renal cell carcinoma, melanoma, and gastrointestinal stromal tumor (GIST). The tyrosine kinase inhibitor (TKI), cabozantinib, demonstrates an antitumor effect in osteosarcoma and Ewing sarcoma. Case Series: Here we describe two patients with recurrent and refractory STS. Both patients failed multiple lines of conventional therapy including neoadjuvant radiation, surgical resection, and palliative chemotherapy before achieving partial response with combination cabozantinib and nivolumab. Conclusion: These cases demonstrate the safety and efficacy of using combination nivolumab and cabozantinib in treatment of STS warranting further investigation of immunotherapy treatment.