Abstract LB-226: The effect of cabozantinib to temozolomide and bevacizumab in patients with heavily pretreated relapsed uterine leiomyosarcoma

Background: Although uterine leiomyosarcoma (ULMS) has been treated with adriamycin, dacarbazine, ifosfamide, gemcitabine, docetaxel, et al, the effect is not satisfactory. We have reported the effect of temozolomide (T) combined with bevacizumab (B) in heavily pretreated relapsed ULMS. In this study, we evaluated the effects of addition of cabozantinib (C) to T and B. Methods: From 2009 to 2015, total 18 patients (pts) with heavily pretreated relapsed ULMS were enrolled. They were treated with T (80mg/body/day) and B (2mg/kg; days 1, 8 and 15, q4 weeks). Since 2013, we expected better efficacy, nine pts out of 18 pts were treated by adding C (140mg/body/week) which is a c-MET inhibitor (TB, n = 9, CTB, n = 9). Treatment was continued until disease progression and/or unmanageable toxicities. The response and adverse events were evaluated using the response evaluation criteria in solid tumors (RECIST), and common terminology criteria for adverse events (CTCAE) version 3.0. Results: As shown in Table, three (18%) of 17 pts had complete response (CR), two (12%) had partial response (PR) and eight (47%) had stable disease (SD) for at least three months. The response rate (RR; CR+PR) and clinical benefit rate (CBR; CR+PR+SD>3mo) were 29% and 76%, respectively. The median progression-free survival was 9.6 (3 - 58) months. When compared CTB with TB, CBR was better in CTB (87.5% vs 67%), but the median administration cycles and progression free interval were not improved. Two peritoneal perforation were observed in CTB. Conclusions: Not only TB but also CTB showed remarkable effect in heavily pretreated relapsed ULMS. These results warrant further prospective and randomized studies. Citation Format: Sayaka Ikeda, Kazuya Kudoh, Naoki Sasaki, Masashi Takano, Tomoko Goto, Ryoko Kikuchi, Tsunekazu Kita, Masaru Sakamoto, Nobuyuki Susumu, Daisuke Aoki, Hiroko Kouta, Yoshihiro Kikuchi. The effect of cabozantinib to temozolomide and bevacizumab in patients with heavily pretreated relapsed uterine leiomyosarcoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-226.