A Phase Ii Study Of Anlotinib In Treating Patients With Relapsed Or Metastatic Primary Malignant Bone Tumor.

11525 Background: Primary malignant bone tumors are rare forms of cancer and include mainly bone sarcomas, which are categorized into 3 common types based on tissue origin: osteosarcoma, chondrosarcoma and Ewing sarcoma. A phase II trial was designed to explore the anlotinib activity in patients with relapsed or metastatic primary malignant bone tumor. Methods: Eligible pts were received 12mg of anlotinib once daily, 2 weeks on and 1 week off until progression or unacceptable toxicity. Key-eligibility criteria were aged 14-70 years, histologically confirmed diagnosis of osteosarcoma, chondrosarcoma, bone derived malignant fibrous histiocytoma, giant cell tumor, Ewing sarcoma and PNET, confirmed previous chemotherapy failure, ECOG 0-1(0-2 for amputation pts), required at least one measurable lesion. We observed PFS, OS, ORR, DCR and AE in this study. Results: From August 2018 to April 2019, 42 pts were included. Of 42 efficacy-evaluable pts, 25 were man, median age was 28 (14-68) years. There were 29 pts of osteosarcoma, 9 pts of chondrosarcoma, 3pts of Ewing sarcoma and 1 pt of bone derived malignant fibrous histiocytoma. The progression-free rate at 12 weeks (PFR12weeks), ORR and DCR were 71.3%, 9.52% and 78.57%. Median PFS was 5.26 months (95%CI = 3.48-8.44). Median OS was 11.40 months (95%CI = 10.09, [ ). Median PFS of osteosarcoma and chondrosarcoma was 4.83 months (95%CI = 3.48, 7.13 ) and 2.76 months (95%CI = 1.31, [ ) respectively. The most common Gr 3-5 anlotinib-related AEs were hypertension (19.05%), hypertriglyceridemia (9.52%), hand-foot syndrome (7.14%), and proteinuria (4.76%). Conclusions: The phase II study shows a promising activity of anlotinib in patients with relapsed or metastatic primary malignant bone tumor and an acceptable toxicity. Clinical trial information: NCT03527888 .