Additional Study Information: The researchers hope to study the effectiveness of an investigational drug called AL3818 in people who have metastatic (meaning their disease has spread) or advanced ), specifically alveolar soft partsarcoma (ASPS), leiomyosarcoma (LMS) and synovial sarcoma (SS). The main purpose of the study isto learn the percentage of patients that respond to treatment with AL3818 if you have ASPS or if AL3818 delays the time until cancer worsens when compared to another drug called dacarbazine if a person has either LMS or SS. Other purposes of the study are to learn how long people respond to AL3818, if AL3818 extends overall survival and the safety of AL3818.