Safety and efficacy of combination therapy with apatinib and doxorubicin in metastatic soft tissue sarcomas: an observational study from multiple institutions

Purpose: Apatinib has shown effectiveness in treating sarcoma. This study aimed to assess the safety and efficacy of apatinib and doxorubicin combination therapy in metastatic soft tissue sarcomas (STS) and to compare the therapeutic effects of two treatments (apatinib after doxorubicin vs apatinib plus doxorubicin) on STS. Patients and methods: A total of 76 patients with metastatic STS who received apatinib and doxorubicin between May 2016 and June 2017 were retrospectively reviewed. Patients were divided into either the apatinib after doxorubicin group (in which apatinib was used after six cycles of doxorubicin chemotherapy) or the apatinib plus doxorubicin group (in which apatinib was used in combination with doxorubicin chemotherapy). Results: There were 55 patients in the apatinib after doxorubicin group and 21 patients in the apatinib plus doxorubicin group. There were significant differences between the apatinib plus doxorubicin group and the apatinib after doxorubicin group in the objective response rate (57.14% vs 25.45%, respectively, p=0.016) and average change from baseline in the target lesion size (−41.71±43.75% vs −1.89±51.61%, respectively, p=0.03). There were no significant differences in disease control rate (85.71% vs 63.64%, p=0.093) and median progression-free survival (8.8 months vs 10.3 months, p=1). Grade 3–4 adverse events were more common with apatinib plus doxorubicin than with apatinib after doxorubicin, and these included leukopenia (5.45% vs 38.1%, respectively, p=0.001), anemia (7.27% vs 28.57%, respectively, p=0.023), oral mucositis (3.64% vs 19.05%, respectively, p=0.046), transaminase increases (0% vs 14.29%, respectively, p=0.011). Conclusion: Our results do not support the use of apatinib plus doxorubicin for metastatic STS unless the specific objective is tumor shrinkage.