Apatinib for patients (pts) with advanced soft tissue sarcoma (STS) after chemotherapy: A prospective, open-label, single-arm, multicentered study.

Abstract

11553 Background: The development of STS therapeutics has been challenging, especially patients who failed chemotherapy. Anti-angiogenesis inhibitors had shown activity in STS, Apatinib is a TKI targeting on VEGFR-2 which has shown activity in many solid tumors. Methods: A Phase II, open-label, Single-arm, multicentered study was conducted in previously treated pts with advanced STS in China. The patients received apatinib 500mg orally qd in a 28-day-cycle, until disease progression or unacceptable adverse events. Antitumor response assessment was performed every 8 weeks per RECIST V1.1. The primary endpoint was PFS rate in 6 months and secondary endpoint was ORR and OS. Results: As cut-off on Jan 20th 2019, a total of 53 patients were enrolled in 9 centers, 51 patients received at least 2 cycles of Apatinib, 1 patient is still in treatment. The main histological subtypes were alveolar soft part sarcoma(n = 11), synovial sarcoma(n = 6), leiomyosarcoma (n = 6), clear cell sarcoma(n = 6) and undifferentiated pleomorphic sarcoma(n = 5). Overall, 27 of 51 patients were progression free at six months and the 6-m PFS rate was 53.32% (95%CI 37.76%, 66.63%). Until final follow-up, the ORR was 18.75% (9/48) and DCR was 87.5% (42/48). Additionally, median PFS was 7.13 (95%CI 3.84, 9.23) months and median OS has reached up to 24.67 (9.30-NE) months. Adverse events (AEs) were detected among all pts, hypertension and proteinuria are the most common AEs, occurred in 84.91% and 73.57% pts respectively. Grade 3/4 related adverse events were detected in 86.79% of pts, Grade 3/4 hypertension was the most common grade3/4 AE (56.60%). Conclusions: Overall, the present study demonstrates that apatinib has a clinically meaningful anti-tumor activity in pretreated STS pts, showing durable responses and prolonged overall survival. Some of the pts had a long-time benefit from the treatment. Apatinib was safe and generally well tolerated. Further studies on specific STS subtypes would be meaningful. Clinical trial information: NCT03064243 .