The study includes a dose escalation phase (Phase Ib) and an expansion phase (Phase II). The dose escalation phase is concluded when the MTD is determined. A dose level (RD) will be designated for the phase II study. For the noncomparative randomized phase II, patients will be randomized to two treatment arms: either ALT-803 at the RD level in combination with BCG (50 mg) or BCG (50 mg) alone.