 Within each dose cohort, subjects will receive weekly 1 day or less frequent IV Q3W infusions of FS102 during an initial 28-day 4-week DLT observation period. During the DLT observation period, subjects will be assessed for safety, tolerability, dose limiting toxicity, PK, immunogenicity, and clinical disease response. Following assessment by the Investigator, subjects without clinical disease progression and without unacceptable toxicity will be eligible to continue receiving FS102 for up to six 21 Q3W to 28-day weekly cycles. 