A pharmaceutical composition for induction therapy which has a hypomethylating agent and a histone deacetylase inhibitor (“HDAC inhibitor”); wherein the hypomethylating agent is a DNA and histone methylation inhibitor such as cladribine and the HDAC inhibitor is, for example, entinostat, panobinostat, vorinostat, and/or romedepsin; further wherein the hypomethylating agent and the HDAC inhibitor are combined in formulations for various administrations including e.g., a continuous delivery system such as a transdermal patch of at least one reservoir or a plurality of reservoirs, oral, a fixed-dose oral combination, intravenous, and combinations thereof. This pharmaceutical composition for induction therapy is used with a monoclonal antibody in the treatment of various cancers, sarcomas, and other malignancies.