Response to apatinib in advanced alveolar soft part sarcoma

Abstract

Background: Alveolar soft part sarcoma (ASPS) is a rare, hypervascular and chemoresistant soft tissue sarcoma. Apatinib, a novel tyrosine kinase inhibitor that highly selectively binds to the ATP‐binding site of VEGFR‐2 within cells resulting in inhibition of tumor angiogenesis, has shown a substantial potential in angiosarcoma, malignant fibrous histiocytoma and round cell liposarcoma. This study aimed to review the clinical efficacy and safety of apatinib in ASPS. Methods: The clinical information of 6 patients with advanced ASPS who received apatinib were collected. The median age of them was 26.5 years old (17y‐32y). Five patients were found with multiple lung metastases and one (case 4) was with locally advanced unresectable tumor. The maximum diameters of locally advanced tumor and metastatic nodules were measured byMRI and thin‐section CT, respectively. All cases received apatinib at initial continuous daily dosing of 500 mg every 4 weeks. Clinical efficacy was evaluated according to RECIST v1.1. The adverse events (AEs) were graded according to CTCAE v4.03. Results: Median follow‐up from start of apatinib treatment was 10.2months (range, 1‐ 21 months). Five of 6 patients who received at least 1 complete cycle of apatinib treatment were eligible for the efficacy analysis (Table). One patient achieved RECIST complete response and stop apatinib treatment after six cycles. Four patients got partial response. No disease progression was found. The current objective response rate to apatinib treatment was 100% (5/5). The most common grade 3/4 treatment‐related AEs were hand‐foot syndrome (60.0%), hypertension (20.0%), and hepatotoxicity (20.0%). No drug‐related severe AEs occurred. At the time of analysis, all patients were still alive and five patients continued to receive apatinib. Conclusions: Our analysis confirms the short‐term efficacy and safety of apatinib in patients with advanced ASPS. This result supports future randomized controlled trial to further verify anti‐tumor activity of apatinib in stage IV sarcomas.